基于生态保护目标的太子河下游河道生态需水量计算

河流生态需水量计算是进行生态水权分配的一项基础性工作,是生态环境保护和水资源配置的依据.随着社会经济的发展,流域水资源短缺和生态环境问题日益突出.针对太子河下游河段水资源开发利用现状及存在的生态环境问题,在确定生态保护目标的基础上,采用月保证率法和生态水力学法计算下游河道不同等级生态需水量,既可以从各月角度反映河道生态需水是一个与自然径流相适应的过程,又注重水生生物的关键期和生境需求.通过Tennant法验证月保证率法和生态水力学法计算结果可靠,最终确定太子河下游河道最小、适宜和理想等级年生态需水量分别为:5.31×108m3、8.52×108m3和12.17×108m3,而且现状流量可以满足最小生态需水量的要求.

Calculation of ecological water requirements in the lower reaches of the Taizi River based on ecological protection objectives

Calculation of ecological water requirements (EWRs) is a basic task for allocating water rights,to provide a basis for ecologically sound protection of the environment and water resources to sustain the ecosystem. With the rapid socio-economic development in China,water scarcity and ecological problems are becoming increasingly prominent. Firstly,to address the issues of water resources utilization and ecological health,the main objectives of ecological protection were identified. Secondly,based on the objectives,the monthly-guaranteed-frequency method and the eco-hydraulics method were applied to calculate EWRs with different grades in the lower reaches of the Taizi River. The results indicated that EWRs were adaptive to natural runoff process from a monthly perspective. The EWRs also emphasized the critical period of aquatic organisms and hydraulic habitat demand. Thirdly,the results were verified though the Tennant method that demonstrated the reliability of the calculation. Finally,the minimum,medium and ideal grades of the annual EWRs were calculated to be 5.31×10⁸ m³,8.52×10⁸ m³ and 12.17×10⁸ m³,respectively. The average annual streamflow of Taizi River in the past decade satisfied the minimum grade of the EWRs.