疏勒河中游绿洲生态环境需水时空变化特征研究

Study on temporal and spatial variation characteristics of eco-environmental water requirement in the middle reaches oasis of Shulehe River Basin

以疏勒河流域中游绿洲为研究区,借助统计分析法、RS和GIS技术方法,选择1970、1980、1990、2000和2013年疏勒河中游绿洲Landsat TM/ETM影像解译成果作为中游绿洲生态演变研究的基础资料,分析得出各种生态系统覆盖状况.根据疏勒河中游绿洲生态环境需水特征,建立了基于天然植被、河流、湿地和防治耕地盐碱化的疏勒河中游绿洲生态环境需水定量化模型,并估算了不同时段不同区域流域中游绿洲生态环境需水量,探讨了疏勒河中游绿洲生态环境需水时空变化特征,从而为区域水资源合理配置和生态环境协调发展提供参考依据.通过计算得出了疏勒河中游绿洲1970、1980、1990、2000和2013年天然植被、河流基本生态、河流输沙、河流渗漏补给、水面蒸发、湿地生态和防治耕地盐碱化生态环境需水量,同时得出总生态环境需水量分别为17.94×108、7.51×108、6.92×108、6.63×108、5.52×108m3.1970—2013年疏勒河中游绿洲总生态环境需水量呈现逐渐减少趋势,减少了12.42×108m3.1970—2013年疏勒河中游绿洲总生态环境需水量空间变化特征呈现瓜州>敦煌>玉门,同时各区域生态环境需水量均呈现减少趋势.

Studies of eco-environmental water requirement is the hot topics in ecology and water science. It is very vital to study eco-environmental water requirement in arid inland river basin,especially because it will help the reasonable allocation and management of water resources and the ecoenvironmental protection and construction in arid regions. The Shulehe River Basin as the third largest inland river basin in Hexi corridor,Gansu province is an important ecological security barrier for northwest China. The middle reaches oasis,as main zone of society,economy and human activity,is a vital ecological defense for protection of the Shule River Basin. In this study,the middle reaches of the Shulehe River Basin oasis as the study area,based on theories and methods of eco-environmental water requirement at home and abroad,used a combination of statistical analyses method and Remote Sensing（ RS） and Geographic Information System（ GIS） method,as well as selected the results of Thematic mapper /Enhanced Thematic Mapper（ TM/ETM）images of the oasis of the middle reaches of the Shulehe River Basin in 1970,1980,1990,2000 and 2013 as basic data in order to study ecological evolution,and analyze the change in coverage of the different ecological system types in the middle reaches oasis of Shulehe River Basin. According to the characters of ecological environment water requirement in the middle reaches of Shule River oasis,based on the natural vegetation,rivers,wetlands and the prevention and control of cultivated land salinization,established an oasis ecological and environmental water requirement quantitative model,calculated oasis ecological environment water demand in the different periods in the middle region different regions,discussed spatial and temporalvariation characteristics of ecological and environmental water requirement in the middle reaches of Shulehe River Basin oasis. The results showed that total of eco-environmental water requirement（ including eco-environmental water requirement of natural vegetation,basic eco-environmental water requirement,transportation sand eco-environment water requirement,recharge of watercourse seepage water requirement,water surface evaporation eco-environmental water requirement,marsh eco-environmental water requirement and combating salinization of farmlands eco-environmental water requirement） in the middle reaches oasis of Shulehe river basin were17.94×10^8m3,7.51×10^8m3,6.92×10^8m3,6.63×10^8m3and 5.52×10^8m3in 1970,1980,1990,2000 and 2013,respectively. The total eco-environmental water requirement showed a gradual decrease trend from 1970 to 2013 in the middle reaches oasis of Shulehe River Basin. The ecological water requirement declined from 17. 94 × 10^8m3 in 1970 to 5. 52 × 10^8m3 in 2013. The order of spatial variation characteristics of total eco-environmental water requirement in the different regions were Guazhou CountyDunhuang CityYumen City from 1970 to 2013,and the eco-environmental water requirement in the different regions showed a declining trend in the middle reaches oasis of Shulehe River Basin. The research results would favor to achieve the optimal allocation of regional water resources and utilization,realize regional,economic,ecological and environmental water system of balanced and sustainable development,while also provide certain reference function for key management program of Dunhuang water resources reasonable utilization and ecological protection,and coordinated and sustainable development among ecological protection,reasonable configuration of water resources and economic society in Shulehe river basin.