Water resources of the Texas Gulf Basin

Abstract

A geographic information system (GIS) has been integrated with a distributed parameter, continuous time, nonpoint source pollution model SWAT (Soil and Water Assessment Tool) for the management of water resources. This integration has proven to be effective and efficient for data collection and to visualize and analyze the input and output of simulation models. The SWAT-GIS system is being used to model the hydrology of eighteen major river systems in the United States (HUMUS). This paper focuses on the integration of SWAT (basin scale hydrologic model) with the Geographical Resources Analysis Support System (GRASS-GIS) and a relational database management system. The system is then applied to the Texas Gulf River basin. Input data layers (soils, land use, and elevation) were collected at a scale of 1:250,000 from various sources. Average monthly simulated and observed stream flow records from 1970-1979 are presented for the hydrologic cataloging units (HCU) defined by the United States Geological Survey (USGS) in the Texas Gulf basin. Average annual sediment yields computed from sediment rating curves are compared against simulated sediment yields from seven river basins within the Texas Gulf showing reasonable agreement.