塔里木河干流上中游丰枯情景下生态水调控研究

Regulation of Ecological Water Volume under High-or Low-flow in the Mainstream Area of the Tarim River

为保护及恢复塔里木河干流受损的天然植被生态系统,利用遥感影像、水文、植被等数据,借助野外监测、地理信息技术与模型模拟相结合的手段,厘定了不同来水频率下河水的损耗量、可调生态水量及生态供水量;结合天然植被的分布特点及需水规律,制定了不同水情条件下的生态水调控方案。结果表明:(1)在10%、25%、50%、75%、90%的来水频率下,生态供水量分别为48.39×10~8m^3、38.05×10~8m^3、27.20×10~8m^3、17.41×10~8m^3和11.93×10~8m^3,对天然植被生态需水量的保障度分别达到217%、171%、122%、78%和53%。(2)在丰水年、平水年、枯水年,设定促进天然植被"恢复"及实现"基本保护"和"重点保护"3个生态目标,以3~5 a为周期、轮灌时段7—9月、持续时间15~20 d的生态水调控方案。具体而言,丰水年在重点保护区、生态敏感区和生态脆弱区实现2~3次的漫溢,平水年在重点保护区(适当情景下涵盖生态敏感区和生态脆弱区)实现1~2次漫溢,枯水年仅通过河损补给重点保护区的生态用水。以上研究可为塔里木河干流水资源的优化配置与天然植被的生态保护及恢复提供重要的科学依据和技术参考。

In this paper,we studied the water loss,available ecological water volume and ecological water supply under different inflow conditions in the upper stream of the Tarim River with the methods of monitoring,GIS and hydrological model. We formulated the ecological water regulation according to the distribution of natural vegetation and the characteristics of water demand supply. The results were as follows：（1） Under the inflow frequencies of10%,25%,50%,75% and 90%,the available ecological water volumes were 48. 39 × 10^8m^3,38. 05 × 10^8m^3,27. 20 × 10^8m^3,17. 41 × 10^8m^3 and 11. 93 × 10^8m^3,which would meet the vegetation water demands of 217%,171%,122%,78% and 53%,respectively;（2） In high-flow year（ below 25%）,normal year（ 25%-75%） and low-flow year（ above 75%）,the designed ecological goals were the ‘regeneration＇,‘basic conservation＇and ‘key conservation＇. An ecological water regulation program with 3-5-year period,rotation flow from July to September and 15-20-day duration was made. The rotational overflow should be implemented 2 or 3 times in the whole area in high-flow year,1 or 2 times in ecological sensitive zone and ecological-fragile area in normal year,and ecological water supply only in the key conservation area by water loss. The study results could provide the scientific foundations and technical guidance for the optimal redistribution of ecological water and the conservation and regeneration of natural vegetation in the mainstream area of the Tarim River.