中文摘要：

本文针对乌梁素海的生态环境问题和实际情况,提出了乌梁素海生态需水的水量目标为乌梁素海调蓄库容在2.4亿m^3～9.43亿m^3,相应的水位目标为1018.35m～1020m,水质生态保护目标为Ⅳ类;依据这些生态保护目标,基于水量平衡法,得出排干系统能够长期提供的水量为5.48×10^8m^3/a,就能够维持乌梁素海的水量平衡;由此乌梁素海的生态需水量主要体现为水质达标Ⅳ类标准的情况下的生态环境需水量,本文基于环境稀释需水量法建立了乌梁素海的生态需水量模型,计算得出了现状条件下在1、5与10年时间内相应的乌梁素海生态需水量为9.73亿m^3,4.62亿m^3与4.38亿m^3;在污染物30%削减方案下,1、5与10年内乌梁素海生态需水量为6.78亿m^3、2.39亿m^3与2.25亿m^3;在污染物40%削减方案下,同等历时的生态需水量为6.07亿m^3、1.76亿m^3与1.53亿m^3。研究成果对乌梁素海生态修复具有重要参考价值。

英文摘要：

This paper considers the existing ecological problem and actual situation of Ulansuhai Nur,and establishes its ecological protection targets,i.e.storage capacity of 240-943 million m^3,water stage of 1018.35-1020m,and water quality of class IV.With these targets and the water balance method,we conclude that a water balance of this lake requires the draining system to provide it a long-term water supply of 5.48×10^8m^3/a.The lake′s water demand by its ecological environments under class IV quality is a primary representation of its ecological water demand.Using the environmental diluting method of water demand,we develops an ecological water demand model for the lake,and its calculations of the lake′s ecological demands in 1,5 and 10 years in the existing conditions are 973,462 and 438 million m^3 respectively.These demands could be reduced through pollution control,for instance,reduced to 678,239 and 225 million m^3 if the pollutant is cut down by 30%,and further to 607,176 and 153 million m^3 if cut down by 40%.The presented results are essential to the planning of ecological restoration in Ulansuhai Nur.