Study On The Lake Surface Changes Of Alice Lake And Its Drives From1976to2009

Lake is a sensitive area for global environmental change, particularly in inlandlakes, which is an annunciator of lakes regional climate and environmental change.The lake water area and environmental change reflect the climate change and humanactivities on the processes of watershed in the inland waters balance and lakes. Withthe continuous development of regional social economy, the domestic water, waterconservancy project construction and other human activities in dry region, destructionof the ecological environment of lake is increasingly severe. So under the joint actionof the natural factors and human activities on the influence of river basin water balance,restoration and maintenance of the lake ecological environment have become the keyof the regional social economy and the lake ecological environment sustainabledevelopment.This article mainly takes Urho district as its research area,and1976,1989,2000,2009,4remote sensing images of Urho district, many years of meteorological andhydrological data, regional water diversion of water conservancy projects as thefoundation data, using supervised classification, comparison and analysis, overlayanalysis and other research methods, the Alice lake dynamic change in1976-2009, thechange law of meteorological and hydrological factors, regional land use dynamicchange and water conservancy project construction in1976-2009Alice lake changeand drive mechanism was studied, the results are as follows:(1) During1976~2009, great changes had taken place in the Alice lake and lakeecosystem, and the lake area was decreased after first increase. During1976~2000, thelake was extremely atrophied, lake ecosystem became increasingly worsened and driedaway in2000.After2000,the Alice lake area expanded gradually, the lake and lakeecosystem recovered slowly,and the lake area reached a peak by2009.(2) From1976to2009, Alice lake change driven by both man-made and naturalcomprehensive effect, in which human activities affect was dominant, especially waterconservancy project construction.From1976to1989,the driving effect of nature factors on Alice Lake change was stronger,but weaker influence of human activities.From1989to2009,the driving effect of human activities,especially of the water conservancy project construction on lake change had major position,leading the direction of change。(3) The change of land use in different times is significant.This article will divide present situation of land use type in Urho District intocultivated land, grassland, forest land, saline-alkali land, water area and unused land. Fromthe1970s to1980s, the total area of grassland and forest land was reduced, the amountof arable land was increased, and the total water area was reduced. From the1980s and1990s, the grassland area was slightly reduced, the total forest land area was reduced ata high rate of speed, cultivated land was increased slightly, the total water area wasreduced. Since the1990s, the total area of grassland and forest land was reduced, thecultivated land area were increased of61.916square kilometers, which mainly camefrom other lands. According to the analysis, the change rate of Urho District land usein the ten years after1990is faster than the ten years before1990.(4) The lake water area change and the hydrologic meteorological elements haveclose relation.The temperature and precipitation from1976to2000are negativelyrelated with lake water area change, but from1976to1989with the slow rise ofprecipitation, atrophy of the lake water rate is small, after1989human activities onlake play a role of main drive change, precipitation on its driving effect is not tooobvious. Poplar river lakes and rivers runoff change have positive correlation, during1976~2000poplar river runoff has been declining, Alice lake lakes are in extremeshrinking; After2000rivers runoff increase, lake area also rose.According to the analysis, since1989section water engineering accelerated theatrophy of the lake, the completion of cross-regional water transfer project make thelake back quickly. It indicates that water conservancy project construction in Alice lakespecial change plays an important role in engineering.