DESERTIFICATION EVALUATED USING AN INTEGRATED ENVIRONMENTAL ASSESSMENT MODEL

摘要: Desertification has been defined as land degradation in arid, semi-arid and dry sub-humid areas resulting from various factors, including climatic variations human activities (United Nations, 1992). A technique for identifying assessing at risk fordesertification the semi-arid, subhumid regionsof United States was developed by Desert Research Institute U.S. Environmental Protection Agency (EPA), using selected environmental indicators integrated into a Geographic Information System (GIS). Five were selected: potential erosion, grazing pressure, stress (expressed function of changesin Palmer Drought Severity Index [PDSI]), change invegetation greenness (derived Normalized DifferenceVegetation [NDVI]), weedy invasives percentof total plant cover. The data over aregional geographic setting GIS, which facilitateddata display, development exploration relationships, manipulation simulation testing. By combining all five layers, landscapes having varying identified, providing tool could be used to improve landmanagement efficiency.