|其他摘要||The Tarim River is the mother river of the people in southern Xinjiang, the ecological environment is very important to the economic development and social stability. As annual increment of population and unreasonable utilization of water and soil resources, the ecological environment problems become more serious than before, which has caught the attention of Governments and scholars. In this study, Tarim River Basin was chosen as the study area, through remote sensing interpretation and field verification, land use / cover data of the Tarim River Basin in 1990, 2000 and 2010 were obtained, then the features of land use/cover changes in different time of watershed were analyzed. Based on the technical criterion for ecoenvironmental status evaluation, the changes of ecological environment in Tarim River basin in recent 20 years were evaluated. Combined with the population, economic and hydrologic data analysis, the reasons of the ecological environment changes in Typical Watershed were discussed. The following conclusions were attained.
(1) The areas of cultivated land, saline-alkali land, waters wetlands and construction land of Tarim River basin during 1990-2010 changed the fastest, which increased 61.97%, 42.27%, 23.43% and 16.43%, respectively; however, the areas of woodland, grassland and sandy area decreased 12.80%, 9.73% and 0.98%, respectively; additionally, the areas of bare rock boulders remained unchanged throughout the study period. Newly added cultivated land was mainly derived from the 11.36% of grass, 5.87% of woodland, 0.60% of sand and 0.29% of the other unused land; newly added water wetlands were mainly derived from 0.87% of grasslands and 0.79% of Sandy; new construction area was mainly derived from the 0.24% grass and 0.98% of cultivated land; new saline-alkali land was mainly derived from the 0.92% of grassland and 0.41% of woodlands; 4.7% and 0.29% of unused land transferred into grassland and arable land, respectively.
(2) From 1990 to 2010, ecological environment index of Ugan-Kucha river basin, Dina river basin, Kaikong river basin and Akesu river basin was between 35 to 55,which was a general level. The ecological environment index of the others was between 20 to 35,which was a poor level. So, as a whole, the status of ecological environment of Tarim River Basin was the worse level.
(3) The ecological environment of Tarim River basin in recent 20 years had no obvious change, but different sub-basins had different variations, such as Kaxgar River Basin, Ugan-Kucha river basin, Cheerchen river Basin and the mainsream of Tarim River turned to benign development gradually; Dina River basin, kaikong River basin, akesu River basin, Hetian river basin and Yarkant river Basin showed a trend of degradation; the ecological environment of Keriya river basin in near 20 years was basically unchanged. The ecological environment in downstream of Tarim River showed a good trend; the upper and middle reaches of the Tarim River showed unceasingly degenerations in the past 20 years.
(4) By analyzing, we can conclude that ecological situation of Kaikong and Hetian River Basin has become worse due to the increasing population and expansion of farmland; however, with the comprehensive management conducting, the eco-environment of main stream is getting better. Even though the ecological situation of Tarim River Basin has changed little during the recent 20 years, which is based on RS data, natural grassland area is decreasing, cultivated land and saline-alkali land area are expanding and water area is increasing mainly caused by the increase of canal system reservoir area, all which brings a huge hidden trouble to the development of river basin ecological environment.|