A GIS‐Coupled Hydrological Model System for the Watershed Assessment of Agricultural Nonpoint and Point Sources of Pollution

Abstract

This paper introduces AVSWAT, a GIS based hydrological system linking the Soil and Water Assessment Tool (SWAT) water quality model and ArcView  Geographic Information System software. The main purpose of AVSWAT is the combined assessment of nonpoint and point pollution loading at the watershed scale. The GIS component of the system, in addition to the traditional functions of data acquisition, storage, organization and display, implements advanced analytical methods with enhanced flexibility to improve the hydrological characterization of a study watershed. Intuitive user friendly graphic interfaces, also part of the GIS component, have been developed to provide an efficient interaction with the model and the associated parameter databases, and ultimately to simplify water quality assessments, while maintaining and increasing their reliability. This is also supported by SWAT, the core of the system, a complex, conceptual, hydrologic, continuous model with spatially explicit parameterization, building upon the United State Department of Agriculture (USDA) modeling experience. A step-by-step example application for a watershed in Central Texas is also included to verify the capability and illustrate some of the characteristics of the system which has been adopted by many users around the world.

History of model development at Temple, Texas

“…Srinivasan developed the first GIS interface for SWAT using GRASS raster-based GIS (Srinivasan & Arnold, 1994). DiLuzio created the first ArcView-SWAT (AVSWAT) interface tool (Di Luzio et al, 2004). AVSWAT was incorporated within the US EPA Better Assessment Science Integrating point and Non-point Sources (BASINS) software package version 3.0, which provides GIS utilities that support automatic data input for SWAT2000 using ArcView (Di Luzio et al, 2002).…”

A Com-Gis Based Decision Tree Model Inagricultural Application

“…An interface program is normally used to convert and organize GIS data into a format required by the model (Liao and Tim, 1997). Close coupling passes information between the GIS and the model via memory-resident data models rather than external files, leading to improved model interactions and performance (Di Luzio et al, 2004). Tightly coupled model integration focuses on incorporating the functional components of one system within the other (i.e.…”

Integration of Rs/Gis for Surface Water Pollution Risk Modeling. Case Study: Al-Abrash Syrian Coastal Basin

“…Typically, in less developed countries, PSs such as sewage from urban areas and NPSs such as sedimentation from deforestation or agricultural practices are the main components of pollution. In developed countries, runoff from agriculture and urban sources are the leading causes of nonpoint pollution (Luzio, et al, 2004).…”

“…The primary requirements for GIS in NPSP modeling can be identified with respect to the features of the modeling work (Hamlett et al 1992;Engel et al, 1993;Tim and Jolly, 1994;Srinivasan and Engel 1994;Srivastava et al, 2001;Luzio et al 2004;Yaghi et al 2012Yaghi et al , 2013. As suggested by previous studies on agricultural NPSP with GIS application, a GIS for this area should be capable of performing complex manipulation and analysis of spatial and non-spatial data for the development and preparation of data inputs to models, providing the linkage mechanisms between models having different spatial representation, facilitating the conversion and standardization of data in digital form of different scales and coordinate systems, and enabling post-simulation analysis through graphical display and spatial statistical summaries that facilitate explanation of modeling results.…”