LAND EVALUATION AND CONSERVATION OF SEMIARID AGROSYSTEMS IN ZARAGOZA (NE SPAIN) USING AN EXPERT EVALUATION SYSTEM AND GIS

In the area around Zaragoza, agrosystems are very fragile. Water is th e main limiting factor for cultivation. Annual rainfall does not excee d 350mm, and the occurrence of convective storms with short and intens e periods of very heavy rainfall greatly increases the danger of water erosion. Also, the mostly squeletic soils in this sparsely vegetated area are prone to erosion. In this semiarid environment, soil essentia lly constitutes a non-renewable resource, and therefore conservation o f these agrosystems is an important issue and a serious environmental concern. Effective land management and soil conservation strategies re quire a variety of information and maps. In this paper, an expert land evaluation system (MicroLEIS) along with a geographic information sys tem (IDRISI) are used to develop a computerized spatial database in or der to suggest suitable land management strategies for environment con servation.