URBAN & RURAL RUNOFF ROUTING APPLICATION

URBAN & RURAL RUNOFF ROUTING APPLICATION

GETTING STARTED MANUAL

xprafts Getting Started Manual Version 2013

TUTORIAL 1: AN OVERVIEW OF XPRAFTS 1 1.1 Introduction 1 1.2 Origin of xprafts 2 1.3 Accessing Help 4 1.4 Contact Us 4 1.5 Graphical Interface 5 1.6 Technical Overview 5

TUTORIAL 2: BASICS OF XPRAFTS 16 2.1 Introduction 16 2.2 Network Terminology 17

TUTORIAL 3: INPUT VARIABLES 23 3.1 Percent Impervious on Various Slopes 23 3.2 Manning’s n values on Rural Catchments with Various Slopes 24 3.3 Manning’s n values in Urban Areas 24

TUTORIAL 4: CREATING A SIMPLE NETWORK 26 4.1 Simple Network Introduction 26 4.2 Loading the Program 26 4.3 Creating the Network 27 4.4 Naming the Network 30 4.5 Setting the Global Database Information 32 4.6 Job Control Data 37 4.7 Link Data 39 4.8 Sub-Catchment Data 40 4.9 Saving the File and Solving the Network 42 4.10 Reviewing Results 42 4.11 Exiting Program 43

TUTORIAL 5: LINKING TO EXTERNAL DATABASES 44 5.1 Introduction 44 5.2 Setting up the Model 44 5.3 Linking with External Database 44 5.4 Importing Global Data 51

TUTORIAL 6: SUBDIVISION - PRE DEVELOPMENT 55 6.1 Using a Template 55 6.2 Adding a Background Image and Zoom Tool 56 6.3 Creating Nodes 58 6.4 Creating Links 59 6.5 Creating Catchments 60 6.6 Initial/Continuing Rainfall Loss Model 64 6.7 Reviewing Rainfall Data 66 6.8 Solving Hydrographs 69 6.9 Reviewing Graphical Results 70 6.10 Tabular Results and Data Input (xp tables) 73

TUTORIAL 7: SUBDIVISION - POST DEVELOPMENT 75 7.1 Entering Nodes and Links for the Post Developed Site 75 7.2 Splitting Catchments into Pervious and Impervious subcatchments. 76 7.3 Optimizing Basin 81

TUTORIAL 8: RIVER EXAMPLE 89 8.1 River Example Introduction 89 8.2 Link and Node Data 89 8.3 Infiltration and Rainfall Data 91 8.4 Weighted Rainfall Data to Individual Sub-Catchments 95 8.5 Gauged Flow or Stage Data 97 8.6 xprafts Review Results 99

TUTORIAL 9: DETENTION BASIN VERSUS ON SITE DETENTION 101 9.1 Introduction 101

xprafts Getting Started Manual Version 2013

9.2 Pre-Subdivision 103 9.3 Post Subdivision 111 9.4 Community Pond (PostSubPond.xp) 114 9.5 Post Subdivision with OSDs 119

TUTORIAL 10: PMP ESTIMATION 125 10.1 Introduction 125 10.2 Create File from Template 127 10.3 Load Background Image and Catchment Extent 127 10.4 Creating Subcatchments 128 10.5 Create catchment collection points 129 10.6 Setting up Spatial Distribution for Short Duration PMP 132 10.7 Automated Storm Generation 134 10.8 Setting up GSDM Data for Shorter Duration Storms 137 10.9 Setting up GSAM Data for Longer Duration PMP 140 10.10 Setting up GTSMR Data for Longer Duration PMP 144 10.11 Analysis and Results 144

xprafts Getting Started Manual Page 1

Tutorial 1: An Overview of xprafts

1.1 Introduction

xprafts is a comprehensive software program to simulate runoff hydrographs at

defined points throughout a watershed based on a set of catchment characteristics and

specific rainfall events. As shown in the diagram below the watershed can be subdivided

into a number of sub-catchments from which runoff hydrographs are produced and routed

through any configuration of network storages, channels, and pipes to determine flood

mitigation options, drainage strategies, or hydraulic design data.

Hyd

rogr

aph

Mod

ule

Q1Q2

Q3

Pipe

#2

Q

Q1(t)

Q2(t)

Q3(t)

t

Q4

Q5Q6

Q9

Diversion Channel

#2

#1

Q10 #2

q(t)*L

Basin ModuleQ7

Q8 Q6(t)

t

Q

Q

t

Q4(t)

Q5(t)

Pipe/Floodway

Q8(t)

Q7(t)

Channel Modules

t

Q9(t)

Q10(t)q(t)*L

Q11

Q12

Q

t

Q12(t)

#1

#1

RI

t t

+ RP

Impervious Area Pervious Area

RI

t t

+ RP

Impervious Area Pervious Area

#2

#1 Initial & Continuing Rainfall

Losses

Philips’ Infiltration Losses

Rainfall Excess

Computed Hydrographs

Rainfall Input

Figure 1. 1 - Graphical Representation of xprafts

xprafts is suitable for application on catchments ranging from rural to fully urbanised.

There are no specific limitations on catchment size. xprafts has been successfully used

for catchments in excess of 20,000km2 including on-site detention. xprafts is capable

of analysing watersheds including natural waterways, formalised channels, or pipes,

retarding and retention basins and any combination of these.


xprafts can be used to evaluate the effects of floods on major storage dams and the

effect of a dam break on watershed. It can also simulate the attenuating effects of channel

and floodplain storage on catchment runoff and assist the formulation of drainage

strategies on developed or developing catchments. xprafts can also be used to

facilitate flood forecasting and subsequent flood plain management activities. The model

allows rapid designs of networks with retarding/retention basins, giving great flexibility in

sizing outlets and emergency spillways to meet optimum requirements.

xprafts can be used as either an event-based model (design storms) or continuous

simulation model (historic time series rainfall data including the areal distribution over

watershed). When operating in either mode, the program has the option to utilise a water

balance model generating continuous excess rainfall. This water balance model is a

modified version of the Australian Representative Basins Model (Black & Aitken 1977,

Goyen 1981, Goyen 2000).

In summary xprafts may be used for any of the following tasks:

Evaluating catchment runoff peaks and volumes;

Sizing of hydraulic elements within a drainage system, including reservoirs and retarding basins, pipes, channels, floodways and river training works;

Examining of drainage and flood mitigation strategies;

Assessing the effects of various catchment changes, or urbanization, on runoff peaks and volumes;

Predicting flows for a flood warning system;

Estimating sewer flows; and

Generating hydrograph flows for hydraulic modeling in other software packages (i.e. xpstorm and xpswmm).

1.2 Origin of xprafts

The Rainfall/Runoff Routing Model described in this manual originated in 1974 in response

to the need of analysing a complex drainage system associated with a major development

in Darwin including a new town for about 150,000 persons.

The program was originally developed jointly by Willing & Partners Pty Ltd and the Snowy

Mountains Engineering Corporation (SMEC) (Goyen & Aitken 1976), and was named the

Regional Stormwater Drainage Model (RSWM).

The concept of the RSWM model followed intensive research in the early 1970s into existing

methods and computing rainfall/runoff models available in Australia and overseas including

Britain, France and the United States of America.

A number of technical investigations were undertaken, including local research, a study

tour by Mr. A.P. Aitken of SMEC (Aitken 1973), and a research project for the Australian


Water Resources Council. Prior to the model being developed a number of research

activities concluded that no appropriate model consistent with Australian conditions and

data was available. This was particularly evident for urbanised and developing catchments.

The basic aim of the development of the RSWM program included the following:

Provide a deterministic model capable of handling any conceivable drainage or river system including natural and artificial storages;

Limit data input requirements to be consistent with the availability of data and the required accuracy of results;

Allow rapid engineering and economic assessment of alternative solutions to flooding and drainage problems. Since 1974 the RSWM model has been applied to studies throughout New South Wales, the Northern Territory, the Australian Capital Territory, Victoria, Papua New Guinea and Indonesia.

Watershed studies have ranged from rural to fully urban with catchment areas ranging

from less than 0.1 ha to several thousand square kilometers. The model has been improved

on a semi-continuous basis since 1974 and continues to be updated as results of ongoing

research is incorporated into the model structure. In the early 1980’s the program was

renamed the Runoff Analysis and Flow Training Simulation program (RAFTS). This was to

reflect the major shift to included detailed urban analysis during the period between 1983

and 1997.

The significant changes during the early 1980’s to the xprafts program are as below:

Separate consideration and routing of impervious and pervious sub areas within a sub-catchment. This procedure was found to greatly improve urban runoff parameter calibration;

Separate routing of pipes and channels in a floodway environment;

Major enhancements in the retarding basin module to include hydraulically interconnected basins, on-line and off-line basins with reverse flow considerations;

Substantial rewriting to make it compatible with micro-computer technology in terms of storage requirements and execution time;

Significant enhancements to the urban drainage capabilities of the program;

Improvements to the very large river basin simulation capabilities of the program.

In the 1980’s the custodianship of the programs development transferred from the general R&D within Willing and Partners Pty Ltd Consulting Engineers to XP Solutions (formerly XP Software), a dedicated development group acting independently of the consulting organisation.

Since 1997 the enhancements have continued and include:


Water Sensitive Urban Design (WSUD) including advanced on-site detention and retention analysis, roof water tank consideration, and advancements in Flood Forecasting facilities;

Advances in sub-catchment analysis to provide improved scaling of process between sub-catchments of different sizes;

Automatic simulation of probable maximum precipitation (PMP); and

Major rewriting of the program to be fully Microsoft Windows compatible and work in full 32 bit operating code.

1.3 Accessing Help

The Help menu and Documentation are available for users and are easy to access. To

access Help information whilst using xprafts you can either make a selection from the

Help menu or simply click on the Help icon located on your toolbar. Some dialogs also

provide a Help option to specific information to that window. If you click on the Help icon

the pointer will turn into a question mark, then click on the area you require more

information about. If this is not active press key F1 while the dialog is open. This will

provide relevant help for all items in that dialog. Printed documentation is also available

from XP Solutions.

1.4 Contact Us

If you do experience difficulties when using our software please contact our technical

support team:

XP SOLUTIONS

Phone. +61-2-6253-1844

Fax. 61-2-6253-1847

PO Box 3064

Belconnen ACT 2617, Australia

Website: www.xpsolutions.com

Email: [email protected]

To improve your skills and increase productivity we would encourage you to attend our

training workshops that are organised on a regular basis. These workshops provide

comprehensive information to help you get the most out of our XP Solutions’ products.

Information regarding these workshops is regularly posted on our website. Alternatively

you can contact us using the email address or phone number as above. Should you need we

can also tailor our workshops to meet your particular requirements as well as organise in-

house training options.


1.5 Graphical Interface

The graphical EXPERT environment (XP) is a friendly, graphic based environment utilized

by a range of software developed by XP Solutions. It encompasses data entry, run-time

graphics and post-processing of results in graphical form, and user definable tables.

Figure 1.2 - Graphical Interface

In xprafts the EXPERT shell acts as interpreter between the user and the model in the

classical style of an embedded expert system. The environment incorporates both pre- and

post-processors which use the expert system knowledge of experienced users to filter input

data and to create and interpret a valid and reasonable model of the system being

simulated.

The EXPERT environment of xprafts allows engineers to devote more time to gaining

an understanding of the problem rather than spending significant effort to the mechanical

tasks of entering and checking data, getting a model to run and interpreting outputs.

xprafts allows users to work with CAD and GIS drawings to create scaled views of the

drainage basin being considered. A detailed base map may be used and drainage networks

can be created as a layer on top of this map. Base maps may be imported from third party

CAD and GIS packages.

1.6 Technical Overview

xprafts is a non-linear runoff routing model used extensively throughout Australia and

the Asia Pacific Region. xprafts has worked very well on catchments ranging from a

few square metres to thousands of square kilometres, for both urban and rural nature.


xprafts can model up to 10,000 different nodes and each node can have any size sub-

catchment attached as well as a storage basin. Additionally multiple on-site detention or

retention structures, within a sub-catchment, can be included in the analysis.

xprafts uses the Laurenson non-linear runoff routing procedure to develop a sub-

catchment stormwater runoff hydrograph from either an actual event (recorded rainfall

time series) or design storm using Intensity-Frequency-Duration (IFD) data together with

dimensionless storm temporal patterns as well as standard AR&R 1987 data. From the

2009 version onwards xprafts simulates Probable Maximum Precipitation (PMP).

Three loss models may be employed to generate excess rainfall. They are:

Initial/Continuing loss;

Initial/Proportional loss; and

ARBM full water balance model.

A reservoir routing model allows routing of inflow hydrographs through a user-defined

storage using the level pool routing procedure and allows modelling of hydraulically

interconnected basins and on-site detention facilities.

Three levels of hydraulic routing are available within xprafts:

Simple hydrograph lagging in pipes and channels;

Muskingum method;

Muskingum-Cunge procedure to route hydrographs though channel or river reaches; and

The hydrographs may be transferred to the xpswmm/xpstorm hydraulic simulation

program for detailed hydraulic analysis.

Hydrograph Generation: The Laurenson runoff routing procedure is used in xprafts

for the following reasons:

it offers a flexible model to simulate both rural and urban catchments;

it allows for non-linear response from catchments over a large range of event magnitudes;

it considers time-area and sub-catchment shape, and

it offers an efficient mathematical procedure for developing both rural, urban and mixed runoff hydrographs at any sub-catchment outlet.

Data requirements for xprafts consist of: catchment area, slope, degree of

urbanisation (derived from the nominated fraction impervious area), losses (observed or

design) and rainfall data.

These parameters are used to compute the storage delay coefficient for each sub-

catchment to develop the non-linear runoff hydrograph. A default exponent is adopted

although the user may specify this value with either a different non-linear exponent or


rating table of flow vs. exponent to define different degrees of catchment non-linear

response.

Each sub-catchment is, by default, divided into 10 equal sub-areas as shown in Figure 1.3.

Each sub-area is treated as a cascading non-linear storage following the relationship

S , where n by default is set to – 0.285 and b is computed from observed catchment

event data or specified in terms of catchment parameters. The rainfall is applied to each

sub-area, and the rainfall excess is computed and converted into an instantaneous inflow.

This instantaneous flow is then routed through the sub-area storages to develop individual

sub-catchment outlet hydrograph. Figure 1.4 shows a diagram for the process.

10

1

2

34

56

78 9

A

1.00.9

0.8

0.70.6 0.5 0.4

0.30.2

0.1

P1

P2P3

P4 P5P6

P7P8

P9

P10

K1

K2

K3K4

K5K6

K7

K8

K9

K10

Catchment boundary

Isochrone

APluviograph

5 Subarea number

K2 Subarea concentrated storage

P7 Subarea total rainfall

Figure 1.3 - Subarea Definition


Su

ba

rea

1S

ub

are

a 2

Pluviograph A

Pluviograph A

Ra

infa

ll In

ten

sity

Exce

ss R

ain

fall

Inte

nsity

Exce

ss R

ain

fall

Inte

nsity

Insta

nta

ne

ou

s In

flo

wIn

sta

nta

ne

ou

s In

flo

w

Subarea excess

rainfall

Subarea excess

rainfall

Instantaneous

Subarea Inflow

Instantaneous

Subarea Inflow

Routing through

non-linear

subarea storage

Routing through

non-linear

subarea storage

Outflow from

subarea 1

Outflow from

subarea 2

Ou

tflo

wO

utflo

w

Time

Time

S=k1(q)*q

S=k2(q)*q

S=volume of storage (hrs*cumecs)

q=instantaneous rate of runoff (cumecs)

k(q)=storage delay time as a function of q (hrs)

Loss model

Loss model

Figure 1.4 - Diagrammatic Representation of Hydrograph Generation

Figure 1.5 - Storm Data

Rainfall: Any local Intensity-Frequency-Duration (IFD) information may be used to

generate hydrographs. Rainfall input can be of two types, either Design Rainfall or Historic

Rainfall. Design rainfall may be entered as a dimensionless temporal pattern with average

rainfall intensity. In Australia design rainfall patterns may be input from AR&R 1987, with

intensity information derived from Volume 2 of AR&R 1987. In this way the appropriate

intensity for the given ARI and duration is computed automatically. The zone of different


regions of Australia may be entered and the appropriate temporal pattern can also be

automatically identified from the inbuilt standard temporal patterns from AR&R 1987.

Historical events may be entered either in fixed or variable time steps allowing long periods

of recorded data to be defined efficiently. Alternatively, rainfall data can be read from an

external rainfall file in ASCII text format either in HYDSYS or XPX formats.

Loss Models: The rainfall excess can be computed using either of the following methods:

Initial/Continuing: The initial depth of rainfall loss is specified along with a continuing rate of loss. For example, 15mm initial loss plus 2.5 mm/hr of any further rainfall.

Initial/Proportional: The initial depth of rainfall loss is specified along with a proportion of any further rain that will be lost. For example, 15mm initial and 0.6 times any further rainfall.

ARBM Loss method: Infiltration parameters to suit the Philip’s infiltration equation using comprehensive ARBM algorithms are used to simulate catchment infiltration and subsequent rainfall excess for a particular rainfall sequence and catchment antecedent conditions.

Figure 1.6 - Hydrologic Losses


Figure 1.7 - Diagrammatic Representation of ARBM Loss Model

The ARBM model are requires data including sorptivity, hydraulic conductivity, upper and

lower soil storage capacities, soil moisture redistribution, groundwater runoff and

catchment drying. These parameters can be determined from field measurements and is

considered to provide a more realistic catchment response to storms - especially with

multiple bursts. More details can be found in the Help file where users can find typical

values for catchments. A proportion of outflows from the ARBM loss method may be

redirected as base flow in a given reach.

Storms: Up to 10 storm events can be analysed in the same run and the results able to be

displayed on the screen and reviewed to determine the critical duration for each location in

the drainage system.


Figure 1.8 – Stacked Storms Dialog

Simulation runs of any period of time, from minutes to years, can be accommodated.

Weighting of different Rainfall Stations in individual sub-catchments is provided.

Figure 1.9 - Catchment Storms


Gauged Data: Gauged Data may be entered by users or read directly from an external file

and compared to the computed hydrograph for to assist the calibration and verification of

the drainage network simulation.

Hydraulics: Hydrographs, which have been developed at individual nodes may be

transported through the drainage system in three ways:

Translation (Lagging): Users specify length of travel time from one node to the next and the hydrograph is translated on the time base by this length of time with no attenuation of peak flow. Appropriate values may be derived by estimating the velocity of flow and consequently the wave celerity, and knowing the length of travel.

Pipe Flow: A pipe may be specified (or sized) to carry flows. Any flows that exceed the capacity of the pipe will travel via the surface to either of two destination nodes. The travel time in this pipe may be either computed or set to a fixed number of minutes.

Channel Routing: A Channel/Stream may be defined using either compound trapezoidal channel or HEC2 style arbitrary sections. The cross-section shape may be imported directly from an existing HEC2 file. The Muskingum-Cunge method is used to route the flow through the channel with the consequent attenuation of the peak flow and delay of the hydrograph peak. Alternatively the detailed channel data simple Muskingum K & X parameters may be utilised.

Figure 1. 10 - Channel Routing


Note: Any nodes may have a diversion link defined in addition to the normal link that will divert some or all of the flow and delay of the hydrograph peak.

The hydrographs generated in xprafts can be transferred to the xpswmm /

xpstorm hydrodynamic models. Hydrographs may also be read into other xprafts

models. For detailed description of xpswmm and xpstorm see separate xpswmm and

xpstorm technical descriptions on our website: www.xpsolutions.com.

Storage Basins (On-Site Detention, Ponds, Dams, etc.): Any nodes in xprafts may

be defined as a storage node. This storage can be small as few cubic meters or large as a

few millions cubic meters. On-line and off-line storages can be simulated and the storages

can be hydraulically interconnected.

Puls’ level pool routing technique is used to route the inflow hydrograph through the

nominated storages. A stage/storage relationship is defined for each storage.

Figure 1.11 - Retarding Basin

Different outlet structures can be modelled including:

circular pipe culverts;

rectangular box culverts;

broad crested weirs;

sharp crested weirs;

ogee weirs;


erodible weirs;

multi-level weirs;

high level outlets;

rating curve outlets;

evaporation; and

infiltration.

Optimization methods are also available to help design the basin. You may optimize the

basin for a maximum discharge or for a maximum allowable storage.

Importing Data: Data may be imported from an ASCII text file in the XPX file format. This

format allows users to create new data and objects as well as update and add to existing

xprafts networks. This facility may be used to import information from GIS’s, FIS’s

CAD packages and other databases. Additionally, data may be directly imported from any

ODBC compliant database including Excel, DFF Dbase, etc. Plan drawings may be

imported from virtually any CAD or GIS packages to be used as a scaled base map. Formats

accepted include BMPs, Shape files, JPEG, DWG, DXF etc.

Output: xprafts provides results and data in various forms. All graphical displays may

be output to printers, plotters and to DXF files.

Graphical Output: xprafts provides graphs of rainfall, rainfall excess, and hydrographs

including total and local components of hydrographs. Stage history and storage history are

also available for any pond or basin in the drainage system. The graphs of multiple

locations may be displayed and printed or results exported to a comma delimited ASCII text

file for use in spreadsheets or databases.


Figure 1.12 - Graphical Output

Tabular Reports: Comprehensive tabular reports can be generated for both hydrology and

hydraulic results and data. In addition, an ASCII text output file is available with detailed

information on both hydrology and hydraulic calculations.

Figure 1.13 - Tabular Reports


Tutorial 2: Basics of xprafts

2.1 Introduction

xprafts models are built to represent the channel/pipe network within an urban, rural,

or partly urban catchment. Figure 1.1 in the Tutorial 1 diagrammatically describes a typical

catchment and channel/pipe network. The network is made up of links with a node at each

end. Each node is at the downstream end of a sub-catchment that collects local inflows.

The minimum number of nodes required to represent a catchment network is one and

located at the catchment outlet. In this case the node sub-catchment’s area is equal to the

complete catchment. Sub-catchments can be optionally split into two portions: usually

representing separate pervious and impervious areas within an urban sub-catchment.

Storm infiltration can be represented by simple initial continuous loss estimates or

infiltration determined using a comprehensive soil water balance module.

Nodes can contain the definition of a retarding basin. Individual sub-catchments can also

contain multiple water sensitive urban design storage structures including on site detention

and retention facilities.

Computed hydrographs, based on an input storm of any durations, are estimated at each

defined node. Additionally, channel routing estimates velocity, normal depth and storage

hydrograph attenuation.


2.2 Network Terminology

1

4

79

1.01

2.01

1.02

3.01

1.03

1.04

Reservoir or retarding

basin

1.05

Main

chan

nel o

r river

Node Point (defining location of

hydrograph)

Isochrones

3.01 Link number

Watercourse

Sub-catchment Boundary

7 Subarea

For clarity, isochrones are shown

only in this subcatchment

Figure 2.1 - Network Terminology

As indicated in section 1.6 each sub-catchment is divided into ten (10) sub-areas (called

isochronal sub areas). These areas are based on equal times of travel to the sub-catchment

outlet. Any sub-catchments can contain distributed water sensitive urban design structures

such as on-site detention tanks/ponds, roof water tanks and/or infiltration/evaporation

structures.


Link A

Link B

Local sub-catchment X

Local

sub-catchment Y

Top subcatchment slope

(X) for link AIntermediate

subcatchment slope (X) for

link B

Alternate subcatchment

slope (X) for link B

Main channel slope AB for

link A

Slope of subcatchment Y

is defined as average

slope based on a range of

alternate weighted

catchment slope

Figure 2.2 - Link Node Network

A link, by xprafts definition, includes an upstream node and a downstream node. The

upstream node has an optional local sub-catchment attached. The upstream node can also

include an optional retarding basin. Links routing is carried out between the upstream and

downstream nodes. The flow entering the upstream node can consist of that from the local

attached sub-catchment, any upstream channel flow (from upstream link) and any flow

diverted from any upstream node.

The slope of the sub-catchment is defined as described in Figure 15, depending on whether

the sub-catchment is at the top of the network or at mid-way in the network. The channel

slope within the channel routing module is simply the average bed slope of the channel

between upstream and downstream nodes.

xprafts divides the sub-catchments or the pervious and impervious portions into a

further 10 isochronal sub areas. In this way large sub-catchments can be represented via

their time/ area (slope) characteristics. By default xprafts adopts 10 equal sub-areas as

shown in Figure 2.3.


10

1

2

34

56

78 9

A

1.00.9

0.8

0.70.6 0.5 0.4

0.30.2

0.1

P1

P2P3

P4 P5P6

P7P8

P9

P10

K1

K2

K3K4

K5K6

K7

K8

K9

K10

Catchment boundary

Isochrone

APluviograph

5 Subarea number

K2 Subarea concentrated storage

P7 Subarea total rainfall

Figure 2.3 – Isochrones

Retarding Basins/Detention Basins are represented in xprafts by defined stage/storage

and stage/discharge curves. A retarding basin can optionally occur at any node in network.

The stage/discharge curve can be internally estimated using defined outlet structure

characteristics.

When two storage structures interact hydraulically during a storm event xprafts

automatically accounts for the varying stage discharge characteristics based on the relative

levels in each basin.


Figure 2.4 - Retarding Basin

A range of spillway conditions are available within a basin including standard weirs,

collapsible weirs as indicated in diagram and direct stage/ discharge routing and curves.


Figure 2.5 - Fuse plug Spillway

Figure 2.6 - Multiple Orifices

Inlets to basins can include multiple level entrances to provide hydrograph attenuation at

various return periods.


Figure 2.7 - Floodway

Channel Routing can be based on simple lagging of hydrographs between the link’s

upstream and downstream node or Muskingum routing directly inputing K and X values or

Muskingum-Cunge routing that automatically computes K and X values based on input

channel x-sections and longitudinal characteristics.


Tutorial 3: Input Variables

The shape of the hydrograph is influenced by the following variables:

Area

Slope

Roughness

Urbanisation (expressed as percentage impervious)

Rainfall loss model

The values shown in the following charts use the rainfall intensities and patterns for Cairns,

in north Queensland. They are used to show the general behaviour of the model. Consider

creating similar curves using the temporal patterns for your project area.

3.1 Percent Impervious on Various Slopes

Flat slopes are more affected by changes in percentage of Impervious area.

- 0.050 0.100 0.150 0.200 0.250 0.300 0.350 0.400 0.450 0.500

0 20 40 60 80 100 120Pe

ak

Flo

w/h

a (

m3

/s/h

a)

'

Percentage Impervious [%]

1 ha catchment with n = 0.025

s=0.01%

s=0.1%

s=1%

0

0.1

0.2

0.3

0.4

0.5

0.6

0 20 40 60 80 100 120Pe

ak

Flo

w/h

a (

m3

/s/h

a)

'

Percentage Impervious [%]

1 ha catchment with n = 0.025

s=5.%

s=10.%

s=15.%


3.2 Manning’s n values on Rural Catchments with Various Slopes

Manning’s n values on rural catchments can have a significant effect on peak flows.

3.3 Manning’s n values in Urban Areas

Manning’s n values in highly urbanized areas have less effect as the slope is greater than

1%.

0

0.05

0.1

0.15

0.2

0.25

0.3

0.35

0 0.01 0.02 0.03 0.04 0.05 0.06Pe

ak

Flo

w/h

a (

m3

/s/h

a)

'

n value

1 ha catchment with 0% impervious

s=.01%

s=.1%

s=1.%

0

0.05

0.1

0.15

0.2

0.25

0.3

0.35

0.4

0.45

0.5

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Tutorial 4: Creating a Simple Network

4.1 Simple Network Introduction

This example takes you through the construction of a basic network using simple link

lagging and global storm data. It is intended to give the user a basic understanding of how

to navigate the environment and build a network. In this model, xprafts calculates the

runoff hydrographs for each of the sub-catchments and then combines and lags them down

the system.

The steps to complete the tutorial follow.

1. Load the Program;

2. Creating the Network;

3. Naming the Network;

4. Set the Global Database Information;

5. Job Control Data;

6. Link Data;

7. Sub-catchment Data;

8. Saving the File;

9. Solving the Network;

10. Reviewing the Results; and

11. Exiting the Program.

4.2 Loading the Program

1) Open xprafts from the Start menu on your Desktop.


2) The default Open File dialogue will appear. At this point you can browse to

an existing file, or

create a new one, or

create a file from template.

The opening window displays a list of the most recently used files. In this example we

will create a new file, so select Open a new database, and then click OK.

3) Enter the File Name as Tutorial 4.xp. Then select Save.

4.3 Creating the Network

The Tool Icons from the Toolbar are used to create a network.

Pointer is used to select objects, move objects, reconnect links, rescale the

window, change object attributes and to enter data.

Text Tool is used to annotate the network.

Node Tool creates nodes representing physical elements such as manholes, inlets,

ponds or outfalls.

Basin Tool. Represents storage structures such as retarding basins detention


ponds, and reservoirs.

Link Tool creates single connections between nodes. May be physical elements or

indicative of a connection, e.g. pipes, channels, overland flow paths, pumps,

orifices, weirs etc. Note that this is to specify a Lagging Link

Channel Tool. Creates Routing Channels.

Diversions Tool. Creates diversions.

Catchment Tool. Digitizes catchments.

Ruler. Measures lengths and areas.

Select All Nodes. If you click on this, all the nodes in the network will be selected.

Select All Links. If you click on this, all the links in the network will be selected.

To create a network, select the Link Tool from the Tool strip. Clicking in the window will

create the node, define its position and give it a unique name. Click where you want

subsequent nodes and the link joining them will automatically be created. When you

double mouse click, the link will be created and the cursor will be ready for creating another

link. If there are more than one branch to the network, repeat the procedure mentioned

above.

To enter data about the elements, select the Pointer Tool and Double Click on them.

The following steps will show you how to create a basic network.

1) Select the Link Tool from the Toolbar by clicking on it . Note that the model will

create nodes and links simultaneously when the link icon is selected.

2) Now click on the window to make node 1 and then node 2 as follows.


3) Then click again to make link 2 and node 3. Double Click to end.

4) Now, click again and create link 3 as shown.


5) Press the ESC key when you have finished. Now the Pointer key will be active.

Note: You should not to be concerned if the nodes, and links names do not match with those

shown in the image above. The names will be changed in the following steps.

4.4 Naming the Network

By default links and nodes that are automatically named as node1, node2… and link1,

link2… as you create them in the model. Although it is not necessary to change the node

and link names from the default names, changing the names may make them more

meaningful to you. The following steps show you how to change the name.

1) Select node 4 by clicking on it. Then Right Click with your mouse and select

Properties. Alternatively, Select node 4 by clicking on it with your mouse and then

selecting Attributes from the Edit menu on your toolbar. Then type in the node

name Cat A.


2) Repeat the procedure with other nodes as shown in the Figure below.

Note that he X and Y coordinates displayed depend on the location of the node in the window

and may differ from those shown in this example. Since the layout is schematic the actual

values are unimportant. However, you can change them at this point if you wish.

3) You may also wish to change the display attributes at this stage. You may edit the

attributes by a group edit as well. Select All Nodes or All Links buttons, go to

Edit/Attributes.


4.5 Setting the Global Database Information

Global database information contains all of the relevant data that is shared by various

components within the model. It usually pertains to such information as storm types,

infiltration and other losses. There is also the facility to control your table definition.

1) Select Global Data from the Configuration menu. Alternatively click on Global

Database icon .

2) Highlight Temporal Patterns by clicking on it. Then click on the New button.

3) A new field will appear with the name of TP#1. This can be altered to suit your

requirements by either using the backspace key or by selecting Rename. In this

example we will use the name 60min.


4) Whilst the name is still selected click Edit and enter the data as follows:


Note: Fraction per time interval is the dimensionless pattern which sums up to 1. For

Australian projects, you can specify the temporal pattern zone based on the ARR 1987 and the

program will automatically picks up the pattern. This will be explained further in the following

tutorials.

5) Click OK to continue.

6) To enter the data for a RAFTS storm, select RAFTS Storms from the Global

Databases dialog. Select New and enter the name Design100Yr-60min.

7) Select Edit to open the Storm Data dialog, enter Average Recurrence Interval as

100 years, under the Average Intensity box select Direct and enter 76.3 mm/hr. For

the Temporal Pattern box, select Reference by clicking on the radio button, then

click on the box to open the Select dialog, highlight 60 min from the list and clicking

on Select. Enter Storm Duration as 60 (min).


Note: You can allow xprafts to estimate the intensity from the IFD curves depending upon

zones by choosing the option IFD calculation and ARR Standard Zone. You can get the IFD

values from the Australian Bureau of Meteorology website:

http://www.bom.gov.au/water/designRainfalls/ifd-arr87/index.shtml

8) Select OK to continue.

9) To enter the Initial/Continuing Loss data, select Init./Cont. Losses. Then click New

and enter the name IL 15-2.5.



10) Then click on Edit.

11) Enter Initial Loss as 15 (mm). Click the Absolute button and enter the Continuing

Loss as 2.5 (mm/hr).

12) Select OK to exit the Initial/Continuing dialog box. Select OK to exit the Global

Databases dialog.


4.6 Job Control Data

1) Select Job Control from the Configuration menu, or select the Job Control Icon .

Job Control allows you to enter data such as time of simulation and the general

model control information.

2) Enter the Title as Tutorial 4. This name will be used for the result output only.

3) Select Simulation Details from the top of the Job Control dialog. Enter Start Date

and Time. The default values 01/01/90 and 00:00 are acceptable for this example.


4) Select Job Definition once again. Click on Global to open the Stacked Storms

dialog as shown below.

5) Check the checkbox Use Storm?. Click in the column under Storm Type, a pull

down menu will appear. Select Rafts. Enter Routing Increment as 1 min and

Number of Intervals as 300. Click on Storm Name, select Design 100Yr-60min and

click on Select.

These steps mean that we will simulate the model from 01/01/1990: 00:00 to

01/01/1990: 05:00 (i.e. a duration of 300 minutes).


6) Click OK to exit the Stacked Storms dialog. Click OK to exit the Job Control dialog.

4.7 Link Data

1) Select the Link between Cat A and Junction by double clicking on the link3.

2) Enter the LAG time as 2.5 min. Select OK to exit the Lagging Link dialog. Note that

a Lagging Link will lag the upstream hydrograph without any attenuation.

3) With link3 highlighted select Copy Data from the Edit menu.


4) Click on OK then highlight the two remaining links by holding the Ctrl key and

clicking on them.

5) Select Paste Data from the Edit menu.

A channel lag of 2.5 minutes has now been copied into the remaining links. Alternatively,

you can use Ctrl + C and -Ctrl + V options from the keyboard to copy and paste

respectively.

4.8 Sub-Catchment Data

1) Open the Node Control Data dialog of Cat A either by

Double Click on the node, or

Highlighting the node with Left Click and Right Click to select Edit Data, or

Highlighting with Left Click and select Edit Data from the Edit menu.


2) Click on Subcatchment Data, and select FIRST Subcatchment.

3) Enter Total Area as 4ha. Enter Impervious as 23%, Vectored Slope as 1%, and

Mannings ‘n’ as 0.025.

4) Select Initial/Continuing under the Rainfall Losses index box by clicking on it, then

highlight IC 15-2.5 and choose Select. Select OK on all dialog boxes to return to the

main network window.

Note: Despite entered percentage of imperviousness, the loss model IC 1.5 -2.5 selected will be

applied to the whole catchment of 4 ha. However, the percentage of impervious area will be

used by the engine when routing the instantaneous hydrograph through non-linear reservoir.

This will be discussed in more details later in the manual.


5) Highlight Cat A and select Copy Data from the Edit menu. Now you must select the

nodes where you wish to paste the data. In this example we wish to paste the data

to all the nodes using Select all nodes. You can select multiple nodes by holding

down the Ctrl key whilst you select the interested nodes by Left Clicking on them.

Select Paste Data from the Edit menu. All the catchment and rainfall data, etc.,

that are entered for Cat A, has now been copied into the remaining 3 nodes.

4.9 Saving the File and Solving the Network

1) To save the file, select Save from the File menu or click on the Save Icon from

the toolbar.

2) From the Analyze menu, select Solve or click on the Solve Icon from the

toolbar. This action will solve the network. If any errors are found a Notepad screen

will appear. You will then need to check the data you have entered before solving

again.

4.10 Reviewing Results

1) To review the results for the network highlight the nodes you wish to review and

then select Review Results from the Results menu or click on the Review Results

Icon after highlighting the nodes. The results are shown as follows:


You can view maximum of 4 graphs per page by selecting the pull down menu from the top

of the page. Variables can also be viewed separately or grouped in a single graph. You can

zoom in, change the font size, the style of graphs or show legends, ect., by Left Clicking and

choose from the drop down menu.

2) When you have finished reviewing the results click on the lower cross in the top right

hand corner of the Review Results window. This will return you to the network

view.

4.11 Exiting Program

To exit the program, select Exit from the File menu or click on the cross on the right hand

corner of the page.


Tutorial 5: Linking To External Databases

5.1 Introduction

This tutorial describes the integration of xprafts and the commercial programs used

ODBC compliant databases such as Microsoft Access, Microsoft Excel, ESRI Arc View, and

MapInfo. The process allows that data which already exist in Asset Management Systems

and Geographic Information Systems (GIS) can be directly linked to the software for use in

the development of the simulation model. While this process is an extremely efficient

method of transferring data between the GIS and model, it may be further automated by

the creation of scripts within the respective GIS packages to produce seamless integration

of the software and GIS.

5.2 Setting up the Model

First we will setup the blank model and then link with the external database.

1) Click on Blank Job in the File\New Menu. Alternatively use Ctrl + N from keyboard.

2) Type in the model name as Tutorial 5 and click on Save.

Now you have a blank model to link with the external database.

5.3 Linking with External Database

1) From the File menu, select the option Import External Databases.


2) Now click on the Select File tab

3) Now browse for the file Model_Data.mdb in Tutorial 5 folder, then Left Click on the

file and Open.

You can see that there is another file, Model_Data.xls, which contains the same data

as Model_Data.mdb . You may select this excel file instead of the *.mdb file.


4) If you click on the Tables dropdown list, you can see the tables that are in the

database.

5) Select Node Data from the Tables dropdown list, you can see the data are

displayed including Node Names, X Coordinates, Y Coordinates, Total Area of the

catchment draining to the node, % Impervious Area, Catchment Slope, and

Roughness.


6) Click on Setup Mappings in the Import External Data dialog to open Variable

Mappings. We will map the variables in the database against the variables in the

xprafts database. For example, “Catchment Roughness” in the external

database will be mapped against “Catchment Manning’s n” in the xprafts

database.

7) Select Object Type & Mandatory Data as Node first. Now, we will map the

Mandatory Data which are the essential data required to create node entities. The

Mandatory Data are Node Names and Positions. Use the dropdown button and

select “Node Name” for “Node”, “X Co-ordinate” for “X Pos”, and “Y Co-ordinate”

for “Y Pos”.


8) From Fields in the Variable Mappings dialog, Left Click and highlight Total Area

(Ha) then click on Insert Mapping.

9) Select Total Area under Subcatchment in the Node Variables dialog and click on

OK. Now you can see that Total Area (Ha) in the external Database is mapped

against the Total Area in Subcatchment in xprafts.


Note the red question mark (?) in Fields (in the Variable Mappings dialog) has been

changed to a green tick mark.

Repeat the steps to map all variables as shown in the table below.

Node Name Node

X Pos X Co-ordinate

Y Pos Y Co-ordinate

Total Area (Ha) Total Area

Impervious % Percentage Impervious

Catchment Roughness Catchment Mannings ‘n’

Catchment Slope (%) Catchment slope

10) Click on OK after completion of mapping. Click on Import in the next dialog.

You can see that 11 nodes have been imported from the external database. Click on

OK.

11) Similarly we will prepare the mapping for each of the link variables. Select the Link

Data table as shown below:


12) Click on Setup Mappings. Select Object Type & Mandatory Data as Link and

complete the mappings as shown below.

Link Name Link

U/S Node US Node

D/S Node DS Node

Hydrograph Lag Hydrograph Lag (min)

13) Click on OK and Import.

14) Now click on Save & Exit in the Import External Data dialog.


15) Click on the Fit Network To View icon . You can now see that the network has

been imported from the external database. You can verify the data by opening the

nodes and links.

5.4 Importing Global Data

We will import the global data bases for the model.

1) From File , select Import Data.


2) Select GlobalData.xpx and click on Open.

3) Double Click on any node and select Subcatchment Data, then select FIRST

Subcatchment and click on Initial/Continuing Loss. Highlight rural and click on

Select to return to the Subcatchment Data dialog.

Note: these databases are imported from *.xpx file.


4) Click on Copy Icon in the Subcatchment Data dialog, then click on the

Initial/Continuing box with rural selected, a pop-up window will tell you what has

been copied. Click on OK to return the network window.

5) In the main network window, highlight all nodes using the Select all nodes Tool, go

to Edit on the main menu, select Paste Data and xprafts notifies you how

many objects and database records have been pasted. Click on OK.


6) From the main menu select Configuration\Job Control, click on Global to open

Stacked Storms, and tick the first storm (10yr10min) in the Use Storm? column.

Click on 10yr10min and Edit to open the Storm Data dialog. Click on the IFD

Calculation box and select IFD Coefficients as Canberra from the database

imported from the *.xpx file.

7) Simulate the model and see the results.


Tutorial 6: Subdivision - Pre Development

6.1 Using a Template

In this example we are going to create the new project using a template. The template will

contain the following data:

rainfall intensity data for the 2 yr ARI;

xp table definitions;and

spatial report definitions.

1) Double click the icon of xprafts from the desktop or the Start button to open

xprafts

2) Select Create From Template from the Open File window as shown:

3) Click on the OK button, browse for the folder to save the model file

4) Type in the name of the model: Pre development

5) Click on Save. The program will show the default template folder. You need to

highlight the relevant template.


6) Click on Cairns.xpt for this model

7) Click on Open (If you save your template files in any other folder, then you need to

browse for it and open).

The window will appear and we will be using the tool strips on the top and right side.

6.2 Adding a Background Image and Zoom Tool

We will now add an optional background image as a reference for our sub division.

1) Click on New Background Image Icon from the top tool strip and the Add

Background Image dialog will appear.

2) Click on the ellipsis (…) to browse for the folder

C:\XPS\xprafts2013SP1\GettingStarted\Tutorial5 select the file Development.dwg

and then click on Open.


You can add images with different extensions. The available file formats are AutoCAD

*.dwg, and *.dxf formats, ESRI *.shp files, and image files such as *.bmp, *.tiff, *.jpg, etc.

In this tutorial we will use an AutoCAD file with the extension of *.dwg. The entire extent

of the drawing will be displayed so we will have to zoom into the project area.

3) Click on the Zoom In Icon from the right tool strip.


4) Drag a rectangle around the project area to zoom in. Alternatively, you can use the

scroll button of the mouse to zoom in and zoom out on the background image. The

right mouse button can be used always to pan apart from the Pan Tool).

6.3 Creating Nodes

Now we are going to create nodes to represent the project area before development.

1) Select the Node Tool , you will see that the cursor has changed to .

2) Click on the locations where you want to create nodes. In this tutorial, we will create

4 nodes as shown in the image below. Press ESC to stop creating nodes, you will see

that cursor has changed to the Pointer Tool .


6.4 Creating Links

Now we will create links by connecting the nodes.

1) From the right tool strip, select the Link Tool .The cursor will change to .

2) Left Click on node 1 and continue Left Clicking on all the nodes, when you reach

node 4, press ESC button. Each time you reach to a node the cursor will change to a

red cross , i.e. you snap the node.


3) You can now see that links have been created as shown in the image below. Note

that these links are lagging links, where hydrographs are just delayed without

attenuation.

6.5 Creating Catchments

Sub-catchments can be created using the Create Subcatchment tool .

1) Select this tool from the right tool strip and you will see the change in the cursor

2) Digitize the catchment by Left Clicking of the mouse, once you finish, Double Click

to end.

3) Now, make sure that the Lock Catchment Icon is switched off .

4) Left click on the catchment polygon, hover the cursor over the catchment polygon

and you will see the Pointer Tool is changed when the cursor reaches the

catchment centroid.

5) Keep the left button of the mouse pressed and move towards node1, once it reaches

the node’s location the cursor will change , release the mouse button then from

the pop-up menu choose Drain Catchment As and connect catchment as

Subcatchment 1.


6)

7) 8) Now, go to the Tools menu and select Calculate Node, and Calculate Area.


9) You can see that the catchment area is computed. Click on OK in the next dialogue.

10) Alternatively, we can measure the catchment area using the Ruler Tool . Click the

on the Ruler Tool from the right tool strip. Draw the catchment boundary. Once the

cursor reaches the starting point, the shape will be changed to cross. While moving

the cursor, you will see that the Ruler Tool measures the Total Distance traversed

and as you reach the starting point, the Total Area will be shown.

11) Double click on the node1 to open the Node Control Data dialog.

12) Click on Subcatchment Data to open the Catchment Data dialog.


13) Click on FIRST Subcatchment. You will not use the SECOND Subcatchment for

this tutorial.

14) You can see that the calculated area (Total Area) is assigned to the catchment.


15) Type in the subcatchment data. The pre developed area has a Vectored Slope of

0.5% grade and a Manning’s n value of 0.025, and Impervious of 0%.

Note: The percentage of Impervious is an indicator for the urbanization of the lot. This

value does not affect the volume of rainfall losses. The loss model specified for the

catchment will be applied for the whole area, 0.562 ha, regardless of the impervious

percentage entered. However, it will be used when routing the instantaneous hydrographs

through the non-linear storage reservoirs. Please refer to Equation 8 in the Chapter 14 –

RAFTS theory, under coefficients B and n section in the help file. The percentage of

Impervious will be used as “U” in Equation 8. If you wish to model some part of the

catchment with another loss model (says impervious area losses), create a second

catchment with the new loss model.

6.6 Initial/Continuing Rainfall Loss Model

To model the rainfall losses we will use the Initial/continuing loss model.

1) Click on Initial/Continuing Rainfall Loss in the dialog above Subcatchment Data,

and select 20l 5C in the Seclect dialog box. If you want to review the data, click on

Edit


2) The loss models included in the template are shown in the Global Databases dialog.

Click Edit to review the data for training purposes.

Note that the first 20 mm of rainfall is lost, then 5mm/hr for the remaining of the

rainfall event. Click OK to finish entering the data and click on Select in the next

dialogue.

3) With 20I 5C highlighted in the Select dialog click on the Copy Icon on the top-

right of the Subcatchment Data dialog . This will copy the data containing in 20I 5C.


From the dialog you can see that the loss model has been copied, click on OK on all

the dialogues until you reach the main window.

4) Click on Select all nodes Tool , and press Ctrl + V on the keyboard to paste the

copied database to all the nodes.

Note that a loss model should be specified to all the nodes to run the engine.

6.7 Reviewing Rainfall Data

Before we calculate the hydrographs for this project we will review the rainfall data that

was included in the template.

1) Click on the Job Control Icon from the top tool strip or click on Configuration from

the menu bar and select Job Control.


2) Click on the Global radio button under Storm Type. The global storms shown in

Stacked Storms are the temporal patterns from ARR volume 2.

3) Routing Increment of 1 minute is selected and Number of Intervals of 4380 min

selected is long enough for the longest rainfall event. Note that Number of Intervals

should be in an ascending order.


4) Click on Storm Name of 30 min. The global data dialog (the Select dialog) is

displayed again (similar to the rainfall loss global data). A list of all the Rafts Storms

included in this template are shown below.

5) Click on Edit to review the storm data.

6) The Average Intensity of storm is entered as Direct in this example. If you can also

select IFD calculation where you need to provide IFD coefficients which can be

derived from ARR1987 guidebook or BOM Website:



Average Recurrence Interval (ARI) under Design Storm, ARR Standard Zone

under Temporal Pattern and Duration are entered using the temporal pattern from

ARR volume 2 (these data are stored in the engine). The Average Intensity of

rainfall entered is then applied to this temporal pattern.

7) Click OK, then Select and then OK on each dialog to close them all.

6.8 Solving Hydrographs

We are now ready to solve for the project hydrographs.

1) Click on the Solve Icon from the top tool strip.

2) The engine will now display the following dialog and then close when the

calculations are completed.





3) Results are written to a file with the extension of *.out and has the same name as

your project’s name. The result data can be viewed either by displaying in the

interface of the software or reading from the text interface.

6.9 Reviewing Graphical Results

1) Click on the node1 from the network window to highlight it

2) To view the graphs either

press F7, or

click on Review Results Icon , or

Right Click on the node and select View Results from the drop down menu

shown below:


3) Results for All Storms will be displayed with the peak runoffs. You can see that 540

min storm gives the peak runoff value of 0.097 cms for the predevelopment site. To

view other storms select them from the dropdown list for storms.

Peak Runoff Value


4) Zoom in by dragging a rectangle around the desired area. The example below shows

rainfall and excess rainfall.

5) Right Click in the graph area and select Undo Zoom from the drop down menu to

zoom out to the full extent.

Initial Loss (20mm)

Continuing Loss (5mm/hr)


6) To close the Review Results window, click on the Close button or click on the lower

cross on the top-right of the window.

6.10 Tabular Results and Data Input (xp tables)

Both the input data and results data can be displayed in tabular format for viewing, editing

and printing. There is one table included in the template but the user may modify this table

and create new table.

1) Press F2 or click on the XP Tables Icon from the top tool strip, or select the XP

Tables option from Results menu.


2) The table name that is already defined and imported from the template will be

displayed. Click on View.

3) By default, Critical Storm is displayed. You can select the storm and other data and

results to view.


Tutorial 7: Subdivision - Post Development

This tutorial begins by creating the job with the Cairns template used in the previous

example but it will be saved as ‘post development’.

The layout of the post development plan is shown below.

Individual lots

Post

developments –

impervious areas

Proposed detention

basin site

7.1 Entering Nodes and Links for the Post Developed Site

1) Enter nodes and links in the locations shown in the layout as in Tutorial 5 (section 5.3

and 5.4). To create links that have polyline shapes hold the Ctrl key and digitize it.

2) Right Click on each node and link and select Attributes. You will be able to change

the names and other display attributes here. Alternatively a group of attributes can

be edited by selecting all nodes and links using Select all nodes and Select all links

then select Attributes from the Edit menu.


7.2 Splitting Catchments into Pervious and Impervious subcatchments.

In this section we will import an *.xpx file which contains the development lots polygon.

1) Go to the File menu and select Import Data


2) Highlight Developed_Lots.xpx and click on Open

3) A warning message will appear indicating no nodes attached to the catchments,

ignore it.

4) Now you can see that 7 polygons have been imported to the model.

Note that two small polygons on lot 1 and lot 2 are the developed – impervious areas.

For the remaining lots, 50 % of imperviousness will be assigned.

5) Click on each polygon and connect to the nodes as Subcatchment1 except for two

small polygons (lot 1 and lot 2) that will be connected as Subcatchment2. See the

image below for the locations of the lots, links and nodes. Refer to Tutorial 5

(section 5.5) for details how to connect polygons to nodes.


6) Now go to the Tools menu, select Calculate Node, and then choose Catchment

Area (see Tutorial 5 (section 5.5)). The catchment areas will be calculated as shown

below.

To change the rainfall losses for the impervious areas, we will create another loss model

called ‘impervious’. This loss model will be applied to the SECOND catchment area. The


Manning’s n value will be changed for the impervious area to represent the roughness of

concrete surfaces.

7) We will create the new rainfall loss model for the impervious-developed areas via

Configuration on the menu bar, select Global data, then select Init/Cont Losses

and then click on New.

8) Type in the name ‘impervious’ and click on Edit. Enter values of Initial Loss and

Continuing Loss as shown in the dialog below.

Note that we use a small initial loss (2 mm) and then no continuing loss (0 mm/h) for

the impervious area.


Reminder: the percentage of imperviousness entered does not affect the rainfall losses. This

percent of imperviousness is the measure of percentage of urbanization and will be used in

routing the instantaneous hydrograph through the non-linear reservoirs by the computational

engine. The loss model specified will be applied to all the catchment area irrespective of the

impervious percentage entered.

9) Click OK on both panels.

Now, we will enter the data for catchments using the XP tables. In the table below we have

split the areas into the pervious and impervious sections and modelled with Percentage

Impervious of 0% and 100% respectively.

10) Press F2 or click on the XP Tables Icon from the top tool strip, or select the XP

Tables option from the Results menu, to enter the XP tables and then select the

Hydrology table. Select Critical Storm from the dropdown list and enter data as

shown in the table below.


11) Run the analysis and review the results as in Tutorial 5 (section 5.9 and 5.10).

You can see that the flow at the node1 has a peak value of 0.129 cm/s for the 90min storm

in comparison with the peak value of 0.097 cm/s obtained for the pre-development results.

We will need to reduce the outflow from the development by 0.033 cm/s (from 0.129 cm/s

to 0.098 cm/s). In order to reduce the flow peak we will provide a detention pond in which

the pond outflow will be limited to 0.098 cm/s.

7.3 Optimizing Basin

1) Right Click on the node Pond and select Basin. You can see that the node has

converted to a basin with a triangle symbol.


2) Double Click on the basin node to open Node Control Data and then click on

Retarding Basin.

To start the design we enter the level for the basin bed as 12.7 m. Next we must enter

the compulsory data for Retarding Basin (the boxes with no tick boxes).

3) Click on Storage in the Retarding Basin dialog and enter the data as below.


Note: If the first level of the basin is 0.0m, it means that the level data is considered

relative to the basin invert level entered above. In this case we are using the actual

levels.


The first storage volume entry must be zero. As the first approximation we will

make the basin 1m deep with a storage of 150m3. Click on OK to complete the panel

and return to the basin panel.

4) Click on General Data in the Retarding Basin dialog.

We must now enter a Storage Routing Interval in m3. A value less than 10% of the

maximum storage volume is recommended. In this example we will use less than 1%

of the volume and still obtain good model runtime performance. Click on OK to

complete the panel and return to the basin panel.

5) Click on Discharge in the Retarding Basin dialog.


We will use a culvert to restrict the flow from the basin. Pipe Diameter is entered as

an initial estimate and we will have it sized later. If Box Culvert is selected Height

and Width must be entered. The culvert slope will be used for partial depth

calculations (before the culvert flows full). Click on OK to complete the panel and

return to the basin panel.

6) Click on Optimization in the Retarding Basin dialog.


Here we will specify the maximum desired discharge and will size the outlet. The

resulting basin depth and storage can then be checked to see if they are acceptable.

Since we will be running several storms, it is unlikely that the same pipe diameter

will be selected for each storm.

7) Run the model using Solve

8) To review the culverts sizes and the output file, click on Results from the menu bar,

then select Browse File… and select the result file *.out. Alternatively you can press

F6 to browse for the result file.

9) In this case a pipe with diameter of 0.275 m was suggested. The depth in the basin

reached 13.266 m for this storm. If this is considered too deep, then the basin area

will have to be increased.

10) Return to Node4 to see if the discharge has been reduced to the pre-development

level.


You can see that the maximum discharge now is equal to the pre-development case

(0.096 cms). Once you have finalized your outlet pipe size return to the basin panel,

untick Optimization and click Discharge to enter the final pipe size. Remember to

enter the maximum height observed in your basin. This can be found by reviewing

results for the basin and selecting basin stage.

11) Once the lower outlet is designed for the minor event we can design for the major

event. This requires to change the rainfall intensities and return periods in the

global storms. Once you have done this, return to the Retarding Basin dialog and

select Normal Spillway.

3 Enter a trial Width and run the model to check the final basin Height and

Discharge for the 100 year ARI event. You may have to alter the spillway

width to change these results. The discharge coefficient may change

depending on your weir crest shape.


Tutorial 8: River Example

8.1 River Example Introduction

Results from xprafts provide flow hydrographs at any point along the river over the

simulation period. In this tutorial we will use about 5-month time series of data. The

example can also be used in flood forecasting to predict flows in future times. xprafts

can also be directly linked to the hydraulic layer of xpswmm to provide accurate water

levels along each reach. The simulation can be dynamically replayed on screen.

Browse to the folder C:\XPS\xprafts2013\GettingStarted\Tutorial7 and open the file River

Example.xp

8.2 Link and Node Data

1) From the Results menu select XP Tables.

Note that you can use F2 key as a shortcut to access the XP-Tables.

2) Select Link in XP Table Options and click on View.

The Table shows all information about links in the job, including Link type – Routing or

Lagging, Channel routing X, Channel routing K, Type of channel data entry direct or

calculated.


3) Click on the cross in the right corner of the window to close the dialog when you

have finished.

4) Open XP Tables again from the Results menu. Click on Add and enter New Table

Name as Nodes.

Note: The table name is only used to identify different tables that may be saved within the

project. You can call it something more meaningful to you.

5) With Nodes highlighted click on Edit to open the Variable Selection dialog. Select

Total Area under Node Data\General Data\SubCatchment from the Variable

Selection dialog.

Click on Append and you can see Total Area will be added to the Selected

Variables dialog.

Note: You will need to scroll down using the scroll bar located on the right side of the

Available Variable dialog.

6) Now following the same steps to add: Local Storm Multiples, ARBM Rainfall Loss,

Catchment Mannings ‘n’, Percentage Impervious, Local Storm Type, and Hydsys

hydrograph.


7) When finished click on OK then View to go to next dialogue.

8) After editing click on Close.

8.3 Infiltration and Rainfall Data

1) The Station A1, A2, A3, A5, A6, and A7 represent the locations of the rainfall gauges,

Suoshi and Zaoshi represent the flow gauging stations.


2) Double click the node A1 in the main network window to open the Node Control

Data dialog, click on Subcatchment Data, select FIRST Subcatchment, then tick

the ARBM radio button and click on the ARBM box to select rainfall losses called

loss 1.

3) With loss 1 highlighted in the Select dialog click on Edit.


4) Click on the Infiltration, etc. tab. Here you can enter the data for Upper Soil, Lower

Soil Drainage Factor and Groundwater Recession Factors.


5) Click on OK to exit the dialog, then click on the cross in the right corner to close the

Select box, and return to Subcathment Data.

6) Click on Local Storm. Select Multiple Hydsys Storms as shown below. If you wish

to see the data, click on the Storm Name column and select HydSys/Prophet

Storms, then select Edit to open the Hydsys Storm dialog. Click on OK or the cross

to exit the dialogs.


7) Click OK to close all dialogs.

8.4 Weighted Rainfall Data to Individual Sub-Catchments

1) Select Global Data from the Configuration menu.


2) Highlight Nishi under HydSys/Prophet Storms then select Edit. Alternatively you

can double click on Nishi to open the Hydsys Storm dialog.

3) Click on Edit. The program will then display the Date, Time and Rainfall

information. Click on Graph to view the Hydsys graph for the station.


4) Repeat the steps for the Station Nanping.

8.5 Gauged Flow or Stage Data

1) Open the Node Control Data dialog for the Station Suoshi by double clicking on it in

the main window.

2) Double Click on Gauged Hydrograph, select the Hydsys Hydrograph radio button,

then click on the Hydsys Hydrograph box. In this example it is labeled as Suoshi.


3) With Suoshi highlighted click on Edit, then select Edit again from the Hydsys

Hydrograph dialog. You will need to wait a few seconds whilst the program loads

the Hydsys file. When the data table is loaded, select Graph. You can now see the

time series discharge data from Station Suoshi.

4) Repeat the process in for the Station Zaoshi.


8.6 xprafts Review Results

1) Solve the network by clicking on the Analyze menu then select Solve… or click on

the Solve Icon .

2) To review the results, solve the network. Select the nodes you wish to examine and

click select Review Results from the Results menu or use the Review Results Icon

.

3) To select multiple nodes to view, as shown below, click on the first node and then

hold down the Ctrl key whilst you select subsequent nodes before selecting Review

Results.

4) To view the output file (*.out) choose Browse File from the Results menu or use the

Browse File icon .

5) The image below shows the output file named River Example.out.


Tutorial 9: Detention Basin Versus On Site Detention

9.1 Introduction

For this example, the files you will need are found in the folder

c:\xps\xprafts2013SP1\GettingStarted\Tutorial9\.

PostSubPond.xp

PostSubOSDs.xp

PostSubOSDsamded.xp

PostSubdivsion.xp

PreSubdivison.xp

PLAN12.dwg

This example primarily uses xprafts to indicate how to size either a community pond

(detention basin) and/or on site detention (OSD) within each allotment to maintain natural

flow peaks after the development of the subdivision. It is assumed in this example that

prior to the creation of the subdivision the total catchment was natural and vegetated.

(Please Note: The sub-catchment areas upstream of the proposed subdivision have been

estimated here for purposes of the example. The sub-catchments throughout the subdivision

are also only rough estimates and may not exactly fit the real project).

Assumed Total Catchment Breakup

The example firstly sets up the model with nodes and links to represent locations where

potential OSD may be placed at the low point along the allotment boundary as well as the


potential site for a community pond and then nodes to collect water from upstream sub-

catchments and roadway drains.

The screen capture above shows the suggested node/link layout with the imported

AutoCAD drawing of the proposed subdivision as a background. The background has been

utilised to position the nodes and links.

You can view the background by selecting background images from the View menu. Select

New and then click in the ellipses button. Select the PLAN12.DWG file and click on Open

and then OK.

To enlarge the image, select the zoom button .

Click and hold the mouse button down to draw a square around the part of the network you

wish to enlarge.

The aim is to do four runs:

Model 1: Pre Subdivision: All sub catchments are in their natural condition.

Model 2: Post Subdivision: Simply a copy of the pre-sub division model with the impervious

portions as the second sub-area to the appropriate nodes turned on by changing the

impervious % from 0 to 100

Model 3a Community Pond: Uses a small community pond at the outlet of the subdivision

contributing areas that also includes the central roadway.

Model 3b Post Sub division with OSDS: Uses only One Site Detention at each of the 9

allotments to achieve the same reduction. Note with the OSD the central roadway is not


included and consequently OSD has to compensate for both the lot increases as well as the

un-retarded roadway increases.

9.2 Pre-Subdivision

1) Open the PreSubdivision.xp file.

2) The first model, seen below, is used without the background for clarity. This model

is for the pre sub divisional condition with all sub-catchments being in their natural

condition. The location of all nodes however is set in the critical post sub divisional

places.

3) The thick red lines represent the potential locations of post sub divisional OSDs

within each of the 9 lots. The thick black node represents the potential site for a

community pond that will collect all the water from the subdivision. The central line

of nodes represents road drainage once the subdivision is constructed. The road

areas that would be fully impervious would not be included in OSD capture, but

would be intercepted by the community pond.

4) The model also includes the total catchment upstream of subdivision to test the

effects of subdivision on total flow peak at the outlet (Cat Outlet).

(Please Note: The sub-catchment areas (hectares) are assumed for this example only

and do not accurately represents the site as shown).

The areas upstream of the proposed subdivision are assumed to be rural with sub-

catchment slopes of 1% and surface Manning’s roughness of 0.04.

The areas within the boundaries of the proposed subdivision are also assumed rural

pre-subdivision.


When the subdivision is in place it is assumed that the central roadway is 100%

impervious and the areas within the allotments are 50% pervious and 50%

impervious.

The rural area sub-catchments upstream are coded with only sub-area to represent

total sub-catchment.

The sub-catchments representing the individual allotments are coded as split sub-

areas. The first area represents the pervious portion (0% impervious) and the

second area represents the impervious (100% impervious) portion. In the

PreSubdivision.xp model both sub-areas are coded as 0% impervious.

All models are using 60 minute combo rainfall, with a 10 year period assumed and

allow for multiple storms.

6) Job Control Including Storm Data: To examine job control data, including storm

data select Job Control from the Configuration menu.

7) If you click on the Global button you will be able to examine the stacked storms

dialog.


8) To view the Storm Data for this example, click on the button labelled 10yr KL

Combo Storm in the Storm Type column.

9) With 10yr KL Combo Storm highlighted click on Edit.


10) In Temporal Pattern section, select the Reference button and click in the empty

box. Highlight 60minCombo temporal pattern and click Edit.

After you have finished examining the data close all dialog boxes to return to the network

window.

Sub-Catchment Data: In this example we will examine the sub-catchment data by looking

at Node 225.


i. Double click on the Node 225. The Node Control Data dialog box will appear.

ii. Click on the Sub-Catchment Data button.

iii. Click on the FIRST Sub-Catchment button


iv. Click on OK when you have examined the data and then double click on the

SECOND sub catchment checkbox.

v. Click on OK.

Rainfall Loss/Infiltration Data: In this example we have assumed Initial Loss-Continuing

Loss rate.


xprafts can alternatively estimate infiltration on a continuous basic using a full water

balance model (ARBM Loss Method).

Channel Routing: Simple lagging of hydrographs has been used in this example. On this

link it is 0.2 minutes. xprafts can, however, carry out detailed hydraulic routing if

hydraulic characteristics of channel provided.

Solving Model: Choose Solve from the Analyze Menu, or use the Solve Icon from the

Toolbar.

Review Results: Now we will see the results at outlet of proposed subdivision areas and at

outlet of total Catchment in main drain.

1) Select the node 280. Select Review Results from the Results menu.


2) Close the results window using the lower of the two crosses in the top right hand

corner. Select the node CatOut and select Review Results from the Results menu.

3) Close the results window and then select Close from the File menu to close the file.


9.3 Post Subdivision

Open the file PostSubdivision.xp.

This model is simply a copy of the Pre Subdivisional model with the impervious portions as

the second sub-area to the appropriate nodes turned on by changing the impervious %

from 0 to 100.

The objectives of this model are to see how much the peak has increased at the potential

community basin site shown as larger thick black node, and in the main drain outlet that

collects water from the subdivision as well as upstream rural areas.

This will provide the information (i.e. the maximum pre subdivision peak discharge) that

the post development peak discharge needs to be reduced to.

Changes from Pre to Post Subdivisional Node Data:

1) Double click on node 225 to view the Node Control Data

2) Select Sub Catchment Data.

3) Click on the FIRST Sub-catchment button


4) Click OK when you have examined the data, then click on the SECOND sub-

catchment button

5) Click on the Rainfall Losses button, label as Imploss in this example. With Imploss

highlighted in the Select dialog click on Edit.


6) Close all windows and return to the network view.

Post Subdivision Results:

1) Click on the node 280 and select Review Result from the Results menu or use the

Review Results icon.

2) After you have examined the results click on the lower of the two crosses in the top

right hand corner to close the window and return to the network window.

3) Select the node 312 and review the results again.


The post peak increased at the contributing subdivision area from 0.53m3/s pre peak to 0.86

m3/s. There is probably a need to reduce this back to the pre peak magnitude or even lower

if the existing receiving drain is of lower capacity.

(Please note: Sometimes the post peak may not increase at the most downstream outlet

within the main drain as it enters the major creek. Depending on the characteristics and size of

the subdivision in relation to total catchment above there can be a decrease as well. This is

generally due to the flow hydrographs from the subdivision impervious areas peaking earlier

than the respective rural areas. This causes a timing difference and hence does not always

lead to an absolute increase in peak discharge at ultimate outlet).

In this example we will assume we still have to reduce post subdivisional peak to rural level

at node 280 (the outlet of the total sub divisional area.)

e.g. 0.86 m3/s back to 0.53 m3/s. This is the objective for Models 3a and 3b

9.4 Community Pond (PostSubPond.xp)

Model 3a will use a small community pond at the outlet of the subdivision contributing

areas that also includes the central roadway.

1) Open PostSubPond.xp

The third model is simply a copy of the second model and adds the community basin on

and allows it to be designed to meet outlet peak of predevelopment.

For the community pond (Retarding Basin) it is only necessary to click on Retarding Basin

option at node 280. Enter the available storage at the site (either natural or via excavation).

Then enter nominal small pipe outlet that may be an orifice, pipe or box culvert. Select the

Pipe, Outlet Optimization option and enter the desired maximum discharge rate (0.53


m3/s). The output from the model will provide the required outlet size and the maximum

storage to limit the outlet flow peak to the specified target or slightly below.

(Please Note: It is alternatively possible to optimise the Pond to only use a particular available

storage by clicking on Maximum Storage button and entering the target storage in m3).

2) Solve the model using the Solve icon or by selecting Solve from the Analyze menu.

3) The required storage is 43.8 m3 and the maximum depth in the Pond is 0.51 m.

4) Discharge target was reached with 3 X 600mm dia pipes. This result is given at the

end of the PostSubPond.OUT file via the notebook editor icon on the xprafts tool

strip.

Double click on node 280 to open the Node Control Data dialog box. Double click on the

Retarding Basin button.


There are many options in the Pond Retarding Basin Module in xprafts. To view the

different options click on the buttons to open their respective dialog boxes as seen below.

It is possible to add one or multiple spillways to act with larger storage storms, say 100 year

return period.


Or fuse-plug or erodible spillways that are often used to reduce spillways costs and ensure

smaller upstream head rises during large flood events.

Other options include the use of tower type inlet structures with multiple orifice entries. It is

possible to optimize each opening to handle both small and large events to meet target

outflow peaks, say at the 5 and 100 year return period.


Other outlet options include infiltration through Pond Bottom soil strata and evaporation

from the pond surface. This allows the addition of Retention to your Community Pond or

OSDs.

Retention basins as OSD or Community Ponds using combinations of infiltration,

evaporation and water reuse can be advantageous over traditional outlets – as they can

reduce development increases in runoff volume back to natural conditions as well as peaks.

xprafts can apply long term historical rainfall on a continuous basis to assess and

design acceptable retention structures to meet community safety and maintenance

requirements.

xprafts also allows the situation where there are multiple Ponds that may hydraulically

interact to affect the upstream stage/discharge characteristics dependent on the levels in

the respective Ponds.


The model can be run over time periods of single storms up to many years and can be

calibrated to gauged data when available. This can allow analysis of how often Ponds fill

and how long they take to empty. This can be used in the assessment of maintenance and

multiple uses of normally dry pond areas for sporting areas etc. xprafts is currently

being used for flood forecasting as it is in China and rivers systems in Australia.

5) Close the file when you are finished.

9.5 Post Subdivision with OSDs

Model 3b use only On Site Detention at each of the 9 allotments to achieve the same

reduction. (Note that with the OSD the central roadway is not included and consequently

OSD has to compensate for both the increased lot discharges as well as the non retarded

roadway increases).

1) Open the PostSubOSDs.xp file.


2) This model does not use the Community Pond to reduce flows to natural from the

subdivision area but instead uses OSDs within each of the 9 allotments. The

following OSD data is added to each of the allotment nodes.

3) Double Click on node 304 to open the Node Control Data dialog box.

4) Click Sub-Catchment Data button.


5) Click on the button labelled Subdivision density.

6) With Subdivision density still highlighted click Edit.


Note: In this example the allotment storage SSR and Maximum Site discharge PSD are

expressed as m3/ha and l/s/ha respectively. In this way each allotment in the subdivision is

treated equally according to their contributing area.

7) Close all windows and dialogs and return to the network window.

The SSR and PSD are iteratively estimated to cause correct peak discharge at the

subdivision outlet (at location of potential ponds) equal to the natural flow peak of 0.53

m3/s, or lower.

In this example the On-site Detention option is selected at each allotment at the low point

nodes. Further information is given to define the total impervious proportions within the

sub-catchment and the % capture of each into the OSD.

It should be noted here that the roadway does not get captured into the OSD that is located

in private property. This is normal for OSDs.

It is not necessary to have a node at each allotment as in this example. In other examples

urban sub-catchments have contained up to 1000 allotments. The OSDs will be allocated

to all the allotments in the sub-catchment.

8) Solve the model

9) Highlight Node 280 and select Review Results.


The peak at potential Community Pond is 0.526m3/s with OSDs having SSR of 170 m3/ha

and PSD of 80 litres/s/ha.

It would also be possible to mix smaller ponds to optimise design of the total system. If

OSDs were adopted in place of the Community Pond at the outlet then it would also be

possible to simply run the outlets from the top four allotments directly into the existing

perimeter drain. In this way we do not have to bring their outputs back to the potential

pond site as indicated below.

If OSDs were adopted in place of the Community Pond at the outlet then it would also be

possible to simply run the outlets from the top four allotments directly into perimeter drain

that is already there and not drag their outputs back to potential pond site as indicated

below.

Rainwater Tanks

10) The OSD solution can also be further modified where excess capacity within roof

water tanks is now being utilised as part of the OSD solution.


11) Open the Node Control Data dialog by Double Click on any node.

12) Click on the Sub-catchment Data and click on WSUD under Onsite

Detention/Retention button, in this example it is labelled Subdivision Density.

Select Subdivision Density in the dialog then click on Edit.

The inclusion of free air space in tanks allows traditional OSDs in properties to be reduced

in size. xprafts allows for these in its analysis.


Tutorial 10: PMP Estimation

10.1 Introduction

In Australia, the PMP (Probable Maximum Precipitation) storms are estimated using 3

Generalised Methods:

(i) GSDM (Generalised Short Duration Method) for short durations,

(ii) GSAM (Generalised Southeast Australia Method) for longer durations used in

southeast Australia

(iii) GTSMR (Generalized Tropical Storm Method) for longer durations used in parts of

Australia affected by tropical storms.

PMP is defined by the Manual for Estimation of Probable Maximum Precipitation (WMO,

1986) as "...the greatest depth of precipitation for a given duration meteorologically

possible for a given size storm area at a particular location at a particular time of the year,

with no allowance made for long-term climatic trends."

Generalised Methods of estimating PMP use data from all available storms over a large

region and include adjustments for moisture availability and differing topographic effects

on rainfall depth. The adjusted storm data are enveloped by smoothing over a range of

areas and durations. Generalised Methods also provide design spatial and temporal

patterns of PMP for the catchment. More detailed information can be found in the

following website (http://www.bom.gov.au/water/designRainfalls/pmp/index.shtml).

The storms with return periods within 100 years and PMP are estimated using the method

provided in ARR 1997 (Estimation of Large to Extreme Floods – Book Six, ARR 1997).

Note: While xprafts can estimate the PMP values automatically, the user needs to specify

the return period and duration.

This tutorial details the step by step procedure of estimating PMP using xprafts for the

GSAM Sample B catchment (Refer to Guidebook to the estimation of PMP – GSAM, Bureau

of Meteorology, 1997). The catchment is located in the Northeast Victoria with a total area

of 436 km2. The catchment lies in the GSAM Inland application zone, and GSDM needs to

be calculated since the area of the catchment is less than 1000 km² (Refer to the below

images from the Guidebook to the estimation of PMP – GSAM, Bureau of Meteorology).

The Latitude and Longitude of the centroid of the catchment are: 36deg19’S and

146deg36’E, respectively and it falls under Zone2 for Australian Rainfall Temporal Pattern.

In this tutorial, we will simulate the design rainfall events for 5, 20, and 100 years return

period, and PMP. The durations of the design storms are 15 min, 1 hr, 2 hr, and 1 day. It

means that 4 events x 4 durations = 16 design storms will be simulated.

http://www.bom.gov.au/water/designRainfalls/wmopmp.shtml

http://www.bom.gov.au/water/designRainfalls/wmopmp.shtml


Figure 9.1. Generalised Method Zones for GSAM and GTSMR, (Source: The Estimation of Probable Maximum Precipitation in Australia: Generalised Southeast Australia Method – Bureau of Meteorology)

Figure 9.2. GSDM (Source: Guidebook to the Estimation of Probable Maximum Precipitation: Generalised Southeast Australia Method – Bureau of Meteorology)

14

6D

eg

30

min

E

36Deg19min S

Figure 9.3. Location of the catchment (Image from Google Earth)

The data/files supplied to complete this tutorial are:


File Name Type Description

Aerial_Image.jpg Image file Aerial image of the project area

Aerial_Image.jpw World coordinate file File associated with the image file

PMP.xpt XP Template fileWhich contains temporal pattern for PMP, default job

control settings, global databases etc

Catchment_B_Extent.xpx XPX file Contains the extent of the catchment B

Note: users can use the *.shp, *.dwg, *.dxf, or image files to digitize the catchments.

10.2 Create File from Template

First we need to create the file using the PMP.xpt template.

Open xprafts, go to File\New\Create from Template. Name the model PMP.xp and

Save in the desired location.

Now xprafts asks you to select the template in the Template folder in the installed

directory by default. Choose the template named PMP.xpt and click on Open.

The PMP.xpt file contains the GSDM, GSAM, and GTSMR temporal patterns and the IFD

data for the study area.

10.3 Load Background Image and Catchment Extent

Add new background image Aerial_Image.jpg (Refer to as in Tutorials 5 (section 5.2)). Then

load the catchment extent called Catchment_B_Extent.xpx by going to File\Import Data,


browse for the file and Open it. In this example the catchment has been made available for

the training purpose. Users will need to create the catchment, if it is not made available,

using the Create Subcatchment Tool or go to the PMP menu in the main menu, select

Catchment Extent, then Create, and digitize the catchment. You will need define the

whole catchment as well as sub-catchments as represented in the following section.

10.4 Creating Subcatchments

Now digitize three sub-catchments as shown using the Create Subcatchment Tool .

Alternatively, you can add *.shp, *.mif, *.dwg files as catchment background images and

digitize the catchments using the Create Subcatchment Tool.


10.5 Create catchment collection points

Add nodes in the catchments outlet points using Node Tool , then connect these nodes

(from Node 1 to Node 3) using Link Tool .

Now we will connect the catchments to the outlet nodes. Make sure that the Lock

Catchments Tool is switched-off as connecting the catchments to the collection

points. Select Pointer Tool and Left Click on the catchment, you will see that the

Cursor has changed as shown in the image below. Keep the Left Button pressed and release


it when the cursor reaches the outlet node. Select the Drain Catchment As

\Subcatchment1.

Repeat this step for all the other catchments.

Now, select all the nodes by clicking on the Select all nodes Tool . Go to Tools Menu,

select Calculate Node and click on Catchment Area.


You can see that the catchment areas are calculated and assigned as FIRST Subcatchment

to the nodes.

Double Click on any node to open Node Control Data and select Subcatchment Data, and

click on FIRST Subcatchment button. You can see that the calculated area is assigned in

Total Area to the node.

Double Click on link 1 to open Link Lagging and enter Lag as 200 min. Similarly, Lag for link

2 is entered as 350 min.


Now, we will add a loss model to the subcatchments. Go to Configuration\Global Data and

highlight Init./Cont. Losses. Click on New and enter the name as NoInfil, then click on Edit

and enter the values of 0 for Initial Loss and Continuing Loss of Absolute.

10.6 Setting up Spatial Distribution for Short Duration PMP

GSDM Ellipses are used to establish the spatial distribution of PMPs for shorter durations.

Go to PMP in the menu bar, select GSDM Ellipses \Show Ellipses.


You will see the 10 ellipses on the screen now (A – J) and the center point of the ellipses as a

small circle. The next step is to overlay the ellipses with the catchment outline by moving

and rotating to obtain the best fit by the smallest possible ellipse. To do this, click on the

Center Circle of the ellipses and hold Left mouse. Now you will be able to move the ellipses.

To rotate the ellipses, press Shift on the key board.

While moving and rotating the ellipses, you are able to see the PMP Monitor dialogue

which shows the GSDM spatial distribution calculations. To see this monitor click on PMP

from the menu bar, select GSDM Ellipses \Show PMP Calculations.

Then go to PMP\GSDM Ellipses and tick on Lock Ellipses. You can see that the ellipses are

locked and cannot be moved.

You can lock the nodes and catchments as well using the tools respectively.


10.7 Automated Storm Generation

Automatic Storm Generator is used for generating storms with any storm durations with

any return periods. Storms up to 100 years return period is estimated using the IFD

coefficients, rainfall duration, and temporal pattern depending upon the zone (Reference:

AR&R 1987).

To activate the Automatic Storm Generator, go to Configuration\Job Control.

Alternatively click on Job Control Icon and select Job Definition. Tick on the Automatic

Storm Generator radio button.

Now you can see the Global Storm Generator dialogue. Click on the Global Storms tab.


Click on IFD and select the global database for IFD coefficients called Albury. The Albury

data was included in the template file PMP.xpt and represents the IFD coefficients for the

region. Click on Edit and you can see the IFD coefficients for the project area.


Note: You can get these IFD coefficients from the ARR 1987, Volume 2. Design rainfall

isopleths’ maps are available for 2 and 50 years for 1, 12, and 72 hours durations. Location

skewness and geographical factors also available in the ARR volume. Otherwise, you can get

these coefficients from the Australian Bureau of Meteorology website:

http://www.bom.gov.au/hydro/has/cdirswebx/cdirswebx.shtml.

Click on OK and highlight Albury and click on Select in the next dialogue box.

In the Global Storm Generator dialog enter the Zone as 2 as the study area is under zone 2

of the Australian rainfall temporal pattern. Refer to the figure given by ARR 1987 as below:

Figure 9.4. Design Rainfall Temporal Pattern Zones for Australia – Source: ARR 1987, BOM.

In the Global Storm Generator dialog, under Time Control, enter Routing Increment as 1

min; under Simulation Time enter Simulation Time = Storm Duration x 1. Next, tick on

the Storm Duration of 15, 60, 120, and 1440 min and select Return Period of 5, 20, 100, and

PMP.

Note: when you tick on PMP as return period, 10, 20, 25 min Storm Durations will be greyed

out automatically as PMPs will not be calculated for these durations.

Now xprafts will calculate 4 events x4 durations = 16 design storms chosen for the

catchment.

The temporal patterns up to 100 year return period are stored in the program. The engine

will pick up the corresponding temporal pattern for a storm depending upon the zone,

return period, and duration. However, the temporal patterns for the PMP should be

specified by users. For GSDM there will be a single temporal pattern (up to 3 or 6 hours).


Figure 9.5. Temporal Pattern for PMP for short durations (Source: the Estimation of Probable Maximum Precipitation in Australia: Generalised Short-Duration Method, BOM, 2003)

There are different temporal patterns for GSAM and GTSMR depends upon the catchment

area and storm duration. The temporal pattern for GSAM and GTSMR are starting from 24

hours. The user should estimate the in-between values (3-24 hours) as described in the

GSAM and GSTMR Guidebooks from Bureau of Meteorology.

10.8 Setting up GSDM Data for Shorter Duration Storms

Open Job Control\Automatic Storm Generator and select the PMP tab. You can see that

the Total Area of the catchment is automatically calculated. Now enter Latitude of -360 19’

and Longitude of 1460 36’ for the catchment centroid. These values will be used in

calculation of adjustment factors for GSAM and/or GTSMR. Enter PMP Return Period of

1000000 years. Note: data will be used to interpolate values between 100 years and PMP (say,

150 or 200 year return period).

Under GSDM- Generalized Short Duration Method select Duration Limit as <3 hr from

the dropdown list. Click on Temporal Pattern and select GSDM from the global database

imported from the PMP.xpt, click on Select. Note that there is only one temporal pattern for

the short duration PMP estimation that is GSDM .


Now click on GSDM Worksheet to open Global Storms Summary for GSDM and enter the

following values:

Smooth (S) (smooth fraction of terrain) as 0, EAF as 1, and MAF as 0.60.

Note: refer to the Estimation of Probable Maximum Precipitation in Australia: Generalised

Short-Duration Method (BOM, 2003) for more details about terrain types and adjustment

factors. Paragraph below is cited in the guidebook:

“Rainfall from single, short duration thunderstorm events is not significantly affected by the

terrain. Therefore, it is not necessary to classify the terrain of the catchment for durations of

an hour or less. If durations longer than one hour are required, the next step is to establish the

terrain category of the catchment and to calculate the percentages of the catchment that are

‘rough’ and ‘smooth’. ‘Rough’ terrain is classified as that in which elevation changes of 50 m or

more within horizontal distances of 400 m are common. ‘Rough’ terrain induces areas of low

level convergence which can contribute to the development and redevelopment of storms,

thereby increasing rainfall in the area over longer durations. Terrain that is within 20 km of

generally ‘rough’ terrain should also be classified as ‘rough’. If there is ‘smooth’ terrain within

the catchment that is further than 20 km from generally ‘rough’ terrain, an areally weighted


factor of ‘rough’ (R) and ‘smooth’ (S) terrain should be calculated such that R plus S equals

one. If a catchment proves difficult to classify under these guidelines then the whole

catchment should be classified as ‘rough’

“The mean elevation of the catchment should be estimated from a topographic map. If this value is less than or equal to 1500 m the EAF is equal to one. For elevations exceeding 1500 m the EAF should be reduced by 0.05 for every 300 m by which the mean catchment elevation exceeds 1500 m. For most catchments in Australia the EAF will be equal to one.”)

Figure 26 - Moisture Adjustment Factor. Source: GSDM Guidebook, BOM

Click on Update under the GSDM tab from Global Storms Summary. You see that the

GSDM PMP depths are estimated from Equation (in the PMP Values (mm) table) up to 3

hours as we specify the duration limit to < 3 hrs.

Note that Initial Depth Smooth (Ds) in the PMP Values (mm) table for the Smooth Terrain

calculated are 0.


10.9 Setting up GSAM Data for Longer Duration PMP

Now in the Global Storm Generator\PMP Tab, under Long Duration PMP Method select

GSAM. Choose GSAM Zone as Inland. Now we need to specify the Temporal Pattern for

the 24 hours GSAM PMP Storm. Note that we do not need to specify the temporal pattern for


15, 60, and 120 min PMP storms as they fall under short durations, hence the GSDM temporal

pattern will be applied. Select GSAM_ I_ 500_24 as the temporal pattern (i.e. GSAM, Inland,

500 km2, 24h hours).

Now click on Global Storms Summary and Select the GSAM tab.


Under CATCHMENT FACTORS click on Compute for Topographic Adjustment Factor

(TAF) and TAF will be calculated based on the entered latitude and longitude.

Similarly, click on Compute for EPW Seasonal catchment average to calculate for

Summer and Autumn. Alternatively, you can directly enter the values of TAF and EPW.

Note that xprafts calculates the TAF and EPWs values based on the latitude and

longitude of the catchment centroid. It will be more accurate if the average value for the

catchment is calculated by overlaying the catchment outline on the TAF and EPWs grids as

described in the GSAM Guidebook.


Now click on Update in the Global Storms dialog and you can now see that FINAL GSAM

PMP ESTIMATES are calculated.


10.10 Setting up GTSMR Data for Longer Duration PMP

Note that for Catchment B the GTSMR estimation is not required. However, for some other

catchments GTSMR estimation will be required based on the location and the user can follow

the same procedure that is provided for the GSAM. For some catchments both GSAM and

GTSMR will be applicable, e.g. GSAM-GTSMR Coastal Transition Zone. In that case, the PMP

depths should be estimated by both the methods and the maximum value is selected.

10.11 Analysis and Results

Click on Solve to simulate the model. To review results, select the nodes that you wish to

see the results and click on Review Results.

URBAN & RURAL RUNOFF ROUTING APPLICATION

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