GIS based Land Surface Subsurface Modeling New Potential for New Models
Many soil erosion and non point source pollution models have been combined with geographic information systems (GISs) to capitalize on the spatial analysis and display capabilities of these new software tools and provide regional soil erosion and non point water quality assessments during the past decade. These models and the GIS software were developed by different groups of scientists (at different times and places) and the potential benefits and limitations of this integration warrant closer scrutiny. This paper addresses these data integration issues at two levels: (1) the input data requirements and role of GIS in providing these data for six popular land surface/subsurface models (USLE, ANSWERS, AGNPS, CMLS, LEACHM and TOPMODEL) are reviewed, and (2) the types of research that will be required to build stronger links between GIS and land surface/subsurface models and the potential for building new and improved GIS based models in the future are examined. The effect of data resolution (i.e. the number and size of units used to represent model inputs) and input data estimation methods on model results is emphasized because: (1) the GIS based applications vary widely in terms of the data structures and methods used to organize the spatially distributed model inputs, and (2) the development of new GIS based methods for estimating model inputs will promote the development of new and improved environmental models. Introduction Recent GIS based Land Surface/Subsurface Modeling Applications New Potential for New Models? References Cited