GoldSim Technology Group LLC, 2006 Slide 1 Water Balance Modeling Techniques.

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GoldSim Technology Group LLC, 2006 Slide 1 Water Balance Modeling Techniques

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GoldSim Technology Group LLC, 2006 Slide 3 Reservoir Basics Overflow Rate Using the Withdrawal Rate output Varying the Upper Bound (to simulate silting up) Using an Extrema to track peaks/valleys Using a Status element to track status of a Reservoir and control actions (such as pumping)

Transcript of GoldSim Technology Group LLC, 2006 Slide 1 Water Balance Modeling Techniques.

Page 1: GoldSim Technology Group LLC, 2006 Slide 1 Water Balance Modeling Techniques.

GoldSim Technology Group LLC, 2006

Slide 1

Water Balance Modeling Techniques

Page 2: GoldSim Technology Group LLC, 2006 Slide 1 Water Balance Modeling Techniques.

GoldSim Technology Group LLC, 2006

Slide 2

Overview

Reservoir basics– Overflow_Rate, Withdrawal_Rate, changing upper bound– Using Extrema elements to track high and low extremes– Using Status elements to track the status of a Reservoir (and

control actions such as pumping) Using Time Series elements for precipitation and other

histories Using Material Delay elements to simulate seepage and flow Using Convolution elements to simulate a runoff using a

unit hydrograph Generating stochastic precipitation, evaporation and flow

histories Using Allocators and Splitters Using the Reliability Module to simulate equipment failure Share your own techniques

Page 3: GoldSim Technology Group LLC, 2006 Slide 1 Water Balance Modeling Techniques.

GoldSim Technology Group LLC, 2006

Slide 3

Reservoir Basics

Overflow Rate Using the Withdrawal Rate output Varying the Upper Bound (to simulate silting

up)

Using an Extrema to track peaks/valleys Using a Status element to track status of a

Reservoir and control actions (such as pumping)

Page 4: GoldSim Technology Group LLC, 2006 Slide 1 Water Balance Modeling Techniques.

GoldSim Technology Group LLC, 2006

Slide 4

Using Time Series Elements in Water Balance Models

Useful for inputting precipitation, evaporation and other time series

Important to:– Differentiate between rates and values– Differentiate between instantaneous flows

and averages flows Can import data from spreadsheets

Page 5: GoldSim Technology Group LLC, 2006 Slide 1 Water Balance Modeling Techniques.

GoldSim Technology Group LLC, 2006

Slide 5

Using Material Delay Elements to Simulate Seepage and Flow

Delay Time is mean velocity of flow Dispersion can simulate spreading

– Both can be specified as a function of hydrogeologic properties

– Both may change with time (e.g., is material at field capacity?)

Page 6: GoldSim Technology Group LLC, 2006 Slide 1 Water Balance Modeling Techniques.

GoldSim Technology Group LLC, 2006

Slide 6

Using Convolution Elements to Simulate a Runoff Using a Unit Hydrograph

A Convolution element converts an input signal to an output signal via a transfer function– You provide an input signal (e.g., rainfall rate)

and a transfer function (the unit hydrograph)– The convolution integral applies the transfer

function and computes an output (e.g., runoff)

A Delay is a specialized instance of a convolution integral

Page 7: GoldSim Technology Group LLC, 2006 Slide 1 Water Balance Modeling Techniques.

GoldSim Technology Group LLC, 2006

Slide 7

Generating Stochastic Precipitation, Evaporation and Flow Histories

Option1: Build your own Markov (or other) model manually

Option2: Using autocorrelated Stochastics Option3: Use the History Generator element

Page 8: GoldSim Technology Group LLC, 2006 Slide 1 Water Balance Modeling Techniques.

GoldSim Technology Group LLC, 2006

Slide 8

Splitters and Allocators

Should be very powerful elements for water balance models

Splitters split (distribute) flows Allocators route flows based on specified

demands and priorities

Page 9: GoldSim Technology Group LLC, 2006 Slide 1 Water Balance Modeling Techniques.

GoldSim Technology Group LLC, 2006

Slide 9

Using the Reliability Module to Simulate Pumps and Other Equipment

Simulate pump failure, as well as pumps turning on and off

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GoldSim Technology Group LLC, 2006

Slide 10

Do you have any favorite techniques that you would like to share?