Evaluation of land resources using crop models and a GIS

Abstract

The evaluation of land resources has been greatly facilitated by recent advances in information science and computer technology. We describe an effort to move land evaluation into the informa­tion age that resulted in AEGIS, the Agricultural and Environmental Geographical Information System. Although the crop models in the DSSAT are basically one-dimensional, agriculture occurs in time and space. It was a logical step to link DSSAT with a geographic information system. The chapter outlines the evolution of the various versions of AEGIS that culminated in the a version for Windows, AEGIS/WIN. Sample applications of AEGIS are presented in three case studies: the feasibility of small irrigation projects in the Andes of Colombia; the evaluation of alternative cropping systems for former sugarcane land in southern Puerto Rico; and assessment of the possible impact of climate change on regional crop production in the southern USA. The accuracy of output from AEGIS is conditioned by limitations of the crop models and by the quality of soil and weather data and their spatial and temporal variability. Nevertheless, AEGIS is a useful tool for expanding the scope of analysis of the DSSAT from a point to an area. The field of systems-based land evaluation is progressing at a rapid pace, and future versions of AEGIS could be greatly enhanced by taking more advantage of the spatial modeling power of a geographic information system.Key wordsdecision support systemgeographic information systemland evaluationland use planningcrop simulation modelsclimate change