Watershed Tools For MassachusettsWatershed Tools For Massachusetts

Pete Steeves

USGS WRD MA-RI District

A Cooperative EnvironmentA Cooperative Environment MassGIS

– development of centerline data (24k)– creation of the ARCVIEW interface and initial set of tools– AVENUE expertise

USGS WRD -- MA/RI District– initial watershed delineation programs in ARC– compilation of DEM/GRID data and drainage

enforcement programs– working with MassGIS to enhance the watershed tools

with new and improved features based on project applications

Goals for the Development of GIS Goals for the Development of GIS Watershed Analysis ToolsWatershed Analysis Tools

Quick and reliable method for delineating basins from any point on any river in the State

Broad and flexible in its applicability to hydrologic investigations

Demonstrate its use through pilot applications that address management concerns

Datalayer Pre-requisitesDatalayer Pre-requisites

Networked centerline of USGS DLG hydrography with a system of reach codes attached

Sub-basin boundaries within a watershed that will help to minimize the dependence on DEM based basin delineation and speed up subsequent analysis

Drainage enforced DEM/Grid data

Working Environment: ARCVIEWWorking Environment: ARCVIEW

Perform actions on the network such as ‘upstream trace’ and ‘find all downstream events’

Delineate a basin from a selected point on the network

Batch delineate basins using an event table

Make linear events from point events to establish a population of segments

Watershed Tools View Watershed Tools View && Menu Menu

Neponset Watershed Subbasins and Centerline DataNeponset Watershed Subbasins and Centerline Data

Select a Point….Select a Point….

......Delineate a WatershedDelineate a Watershed

Drainage Enforcement…Why and How?Drainage Enforcement…Why and How?

Drainage Enforcement Steps For 24K DEMsDrainage Enforcement Steps For 24K DEMs

Merge DEM derived grids and ‘clip’ to a 4000 foot buffer around selected watershed

‘VIP’ 70% of the cells into a point coverage Run ‘Topogrid’

– resample cell size to 10 meters– input would include vector centerline and VIP elev points– watershed may have to be broken up and pieced back

Run ‘agree.aml’ from University of Texas – exaggerate the depths of the streams by canyonizing them– enhances the topogrid processing – minimize smooth distance tolerance

Run ‘fill’ on the output, followed by ‘flowdirection’ and ‘flowaccumulation’

Application IApplication I

Obtaining streamflow statistics for Massachusetts streams on the WEB– User chooses any point on any stream– The watershed is delineated– The application calculates variables(area of stratified drift, total length of streams, mean

elevation and slope values) from which stream flow statistics are calculated, including:

• Peak-flow frequencies - mean annual, 10-, 25-, 50-, 100-, and 500-year floods

• Low-flow frequencies - 7-day, 2- and 10-year low flows

• Flow durations - 99 through 1 % exceedance probabilities

• August median flow

THE STREAM STATISTICS WEB PAGETHE STREAM STATISTICS WEB PAGEhttp://ma.water.usgs.gov/streamstats/http://ma.water.usgs.gov/streamstats/

THE JAVA APPLICATION WINDOWTHE JAVA APPLICATION WINDOW

ADD FEATURES SUCH AS ROADS ADD FEATURES SUCH AS ROADS TO FIND THE LOCATION OF TO FIND THE LOCATION OF

INTERESTINTEREST

USE MAPS AT SMALL SCALE TO USE MAPS AT SMALL SCALE TO FIND PRECISE LOCATIONSFIND PRECISE LOCATIONS

BASIN DELINEATION MAPBASIN DELINEATION MAP

BASIN FEATURES AND FLOW VALUESBASIN FEATURES AND FLOW VALUES

Application IIApplication II

Characterize water resources (streams, lakes/ponds) on a river network (Neponset River Basin) for water-quality monitoring:– Define a population of stream segments– Determine physical characteristics of stream segments

(length, stream order) – Classify stream segments in terms of watershed

characteristics that might affect water quality (i.e. - land use)

Tributary confluences

Significant lakes (> 5 acres)

Stream Segments are Defined Based on Locations Where a Change in Water-Quality May Occur:

Significant point-source discharges (NPDES sites)

Resulting Segmentation in a Section of the Network

Physical Characteristics of StreamsPhysical Characteristics of StreamsNeponset River BasinNeponset River Basin

0

20

40

60

80

100

120

140

160

1 2 3 4 5

SegmentsMiles

Total:

312 stream segments152 stream miles

45 significant lakes(not shown)

Stream Order

Determining Watershed Characteristics Requires Determining Watershed Characteristics Requires Delineating WatershedsDelineating Watersheds

Batch Delineation

Development of Watershed Tools Development of Watershed Tools in the NHD ArcView Toolkitin the NHD ArcView Toolkit

Currently working on adding watershed delineation functionality to the Toolkit

Focusing on areas where 1:24,000 scale National datalayers are available

Testing the validity of using 1:100,000 scale NHD

Plans to incorporate other tools into the Toolkit (event creation and search, a raindrop tool, batch delineation of watersheds…)