Many spatially distributed environmental models such as hydrology, erosion-deposition and water quality models rely on a cellular or grid structure to capture the landscape. Important input and output data requirements result from this approach. GIS represents an adequate framework for pre- and post-processing geo-referenced model input variables or output data. In this exercise, the first steps for extracting topographic variables and land surface characteristics from basic GIS data are explained.

For more information on this case study, contact:

C.M. Mannaerts and A. Patrono
Department of Water Resources
International Institute for Geo-Information Science and Earth Observation (ITC)
P.O. Box 6, 7500 AA, Enschede, The Netherlands
Tel: +31 53 4874210, Fax: +31 53 4874336, e-mail: mannaerts@itc.nl