SWATgrid: An interface for setting up SWAT in a grid-based discretization scheme

This paper presents a model interface that enables the user to incorporate spatial detail into a SWAT (Soil and Water Assessment Tool) model run. For modeling purposes a watershed has to be spatially discretized. All currently developed interfaces preparing SWAT input data use the sub-watershed discretization scheme. The application of this concept results in a loss of spatial information in the input data such as land-use or soil type maps. Setting up SWAT in a grid-based scheme would avoid this loss of information. Therefore, an interface preparing the input data for setting up SWAT based on grid cells was developed: SWATgrid. SWATgrid allows the user to incorporate spatial detail into a SWAT model run and enables the coupling of spatial information such as remote sensing data with SWAT. In this paper the functionality of SWATgrid will be demonstrated by comparing results of SWATgrid with conventional SWAT model results. The development of the grid-based discretization scheme will be presented using a SWAT test data set. Current developments as well as problems that occurred will be discussed and future steps will be pointed out. (C) 2011 Elsevier Ltd. All rights reserved.