论文部分内容阅读
研究水库下游河道中水文情势的变化是研究水利工程对河流生态系统胁迫的一种新途径。RVA(Range of Variability Approach)方法基于32个参数从水流的等级、频率、历时、发生时间、变化率5个方面的水文特征对建坝后河道水流情势的变化进行定量分析,并给出各个参数确定的满足河道生态要求的流量特征变化范围。将该方法运用于位于浙江省飞云江上的珊溪水库,以其下游的峃口水文站为观测点,分析了该站52a的日流量资料,计算出了河道水流参数满足生态系统要求的可控制范围。并在原RVA评价各参数水文变化度的基础上进行了改进,利用改进的方法对32个参数的变化情况以及整个河流水流情势的变化情况进行了评价。通过与原方法的比较,结果表明改进后的RVA方法更为客观。根据计算结果,建坝后该河流的整体水流情势变化度为中度,流量的频率和历时指标变化最大,低流量事件的持续时间减少,出现次数增多,严重影响了河流的生态功能。
Studying the changes of hydrological situation in the lower reaches of reservoirs is a new way to study the ecological stress of water conservancy projects on rivers. Based on 32 parameters, the RVA (Range of Variability Approach) method is used to quantitatively analyze the changes of water flow patterns after the dam is constructed based on five aspects of hydrological characteristics such as the grade, frequency, duration, occurrence time and rate of change of water flow, Determine the range of flow characteristics to meet the ecological requirements of the river. The method was applied to Shanxi Reservoir located on Feiyunjiang River in Zhejiang Province. Based on the observation point of the downstream Hydrant Station, the daily flow rate of 52a was analyzed, and the river flow parameters were calculated to meet the ecosystem requirements Control range. The original RVA was used to evaluate the hydrological degree of change of each parameter. The improved method was used to evaluate the variation of 32 parameters and the change of the river flow pattern. Compared with the original method, the result shows that the improved RVA method is more objective. According to the calculation results, the overall water regime change degree of the river after the dam is moderate, the frequency and duration index of the flow change the most, the duration of low-flow events decreases, the number of occurrence increases, seriously affecting the ecological function of the river.