Environmental Quality Assessment of Tibet Based on 3S

TM and HJ remote images were applied to land use interpretation of Tibet on the platform of Erdas software. The spatial distribution characteristics of Tibet land use were analyzed based on Landscape Ecology theory and GIS. The Ecological Index (El) was calculated to access Tibetan eco-environmental quality. To validate the interpretation accuracy, GPS was used in field checking. The results show: (1) the farmland area of Tibet is 0.66%t of whole area. Woodland area is 164938.29 km(2)( 13.71%). Grassland is 548651.10 km(2) (45.60%). Water area with 84392.81 km(2) is 7.01%. Urban land is 3020.20 km(2) ( 0.25%). Unutilized land is 460847.68 km(2) (32.765); (2) High coverage grasslands are mainly distributed in some southern Tibetan counties, such as Xigaz, Nyemo, Lhongzi, Naidong, Yatung, Gyantse and Renbu (3) among 73 counties, there are 44 counties' environment is moderate level, 18 counties' environment is good level. Just one county's El is excellent level.