CRWR Online Report 2000-3
An Analysis of a Methodology for Generating Watershed Parameters
using GIS
By David Mason, MSE, and David R.
Maidment
ABSTRACT
A basic methodology is presented for generating watershed
parameters in a GIS format. The calculation of drainage area, average curve
number, and average precipitation parameters were made for water right locations
as part of the TNRCC’s Water Availability Modeling project for the Nueces,
Guadalupe, San Antonio, and San Jacinto river basins. The effectiveness of the
methodology was analyzed. The study showed that 90-meter (1:250,000 scale) DEMs
alone could not be used to accurately delineate watersheds. However, 30-meter
(1:24,000 scale) DEMs were used to accurately delineate watersheds ranging from
a size of 10,000 square miles to 0.15 square miles in areas with well-defined
drainage. The limitations of using 30-meter DEMs were a 10-fold increase in both
file size and processing time. Also, the increased resolution of the DEMs still
had difficulty defining accurate watersheds in areas with an average slope of
less than 0.002 m/m.
CRWR Online Report 2000-3
An Analysis of a Methodology for Generating Watershed Parameters using
GIS
By David Mason, MSE, and David R.
Maidment
The highlighted links that follow are connected to Adobe pdf files of the
corresponding material. To view them you must have the Adobe Acrobat Reader 3.0.
Download the Adobe
Reader
View
the Report...(2.4MB)
These materials may be used for study, research, and education, but please
credit the authors and the Center for Research in Water Resources, The
University of Texas at Austin. All commercial rights reserved. Copyright 2000
Center for Research in Water Resources.
Go Back to the
Digital Library