LINKING DSSAT V3 TO GIS: AEGIS/WIN AEGIS/WIN stands for Agricultural and Environmental Geographic Information System for Microsoft Windows. It was developed to improve presentation and understanding of simulated results through visualization of simulated outcomes using maps of farms or regions. AEGIS/WIN links a geographic information system with the Decision Support System for Agrotechnology Transfer DSSAT, version 3. It runs on IBM compatible Personal Computers using the GIS software ArcView 2.0 from ESRI and has a completely mouse and menu driven user interface. AEGIS/WIN was written using the macro programming language, Avenue, of ArcView. AEGIS/WIN can be used for any region or coverage, i.e. piece of land on a farm, region, or country scale. For a coverage, different crop management practices can be assigned to different fields or polygons, i.e.homogenous land areas. AEGIS/WIN allows one to evaluate the effects of various practices on yield in order to estimate crop production, to explore (optimal) land use options, and to determine potential environmental impacts. The user interface can be used to perform the following functions: 1. Create thematic maps based on (i) polygon-characteristic features of a coverage such as soil type, total area, weather station, and climate zones, or (ii) landuse-characteristic features such as the crop and variety. 2. Define and modify various crop management practices using DSSAT v3. These practices may vary in the crop, variety, planting, irrigation, fertilization, and/or residue management. 3. Perform simulations and examine results of several simulated factors. Simulation results can be graphically presented in thematic maps. Statistical results tables can be created and shown using graphs. 4. Maps, graphs and tables can be printed. AEGIS/WIN uses the crop models of DSSAT v3 which are written in FORTRAN, according to the standard crop model inputs and outputs as defined by the International Benchmark Sites Network for Agrotechnology Transfer project (Tsuji et al., 1994; Jones et al., 1994; Hoogenboom et al., 1994). AEGIS/WIN can be used with each of 11 crop models in DSSAT v3. The User's Manual provides instructions for installing and using AEGIS/WIN. It also contains technical information concerning the structure of the INFO data bases, the location of files, and some key programming concepts. SYSTEM REQUIREMENTS: Hardware: 1. IBM compatible Personal Computer 80386 or higher 2. Harddisk with at least 30 megabytes of free space a. 18 MB for DSSAT v3 b. 9 MB for ArcView 2.0 c. 1 MB for AEGIS/WIN 3. Minimum of 8 MB random access memory (RAM); 12 to 16 MB recommended. 4. Minimum of 5 MB swapfile (virtual memory on harddisk); 12 MB recommended. 5. Microsoft compatible mouse Software: 1. MS-DOS or PC-DOS 3.1 and higher 2. MS-Windows 3.1 or higher 3. DSSAT v3 4. ArcView 2.0 TO ACQUIRE AEGIS/WIN: Contact IBSNAT by fax (808)956-3421 or email ([log in to unmask] ) for details. Cost is $95 plus shipping and handling.