ISAREG is a conceptual non-distributed water balance model for simulating crop irrigation schedules at field level and to compute irrigation requirements under optimal and/or water stressed conditions. To support the users of ISAREG in creating appropriate crop data inputs, the auxiliary program KCISA is linked with the simulation model. GISAREG is a Geographical Information System (GIS) based application integrating both ISAREG and KCISA, which was developed for application in the Aral Sea basin to support implementation of improved farm irrigation management. The integration concerns the creation of spatial and weather data bases, the models operation for different water management scenarios, and the production of crop irrigation maps and time dependent irrigation depths at selected aggregation modes. The resulting information on alternative irrigation schedules is therefore spatially distributed and shall be used to identify practices that lead to water saving and provide for salinity control. The paper includes brief descriptions of ISAREG and KCISA, reports on the databases and models integration and use, and presents selected application results.