基于丰平枯水年的湖泊生态水位计算

Lake Ecological Water Level Calculation Based on Wet,Normal and Dry Years

针对现有湖泊生态水位计算方法的不足,以逐月最小生态径流计算法和逐月频率计算法为基础,提出了基于丰平枯水年的逐月生态水位计算法,即同时考虑天然水文情势中年际尺度的丰平枯变化与年内尺度的逐月变化,将年均水位系列以37.5%和62.5%保证率划分丰平枯水年,并以各月最低水位和25%、75%保证率分别计算出湖泊最低生态水位和适宜生态水位。在鄱阳湖的应用表明,区分丰平枯水年的生态水位能更好还原天然水位变化过程,可为湖泊水资源保护提供指导。

Given the deficiency of the existing calculation method of lake ecological water level,based on the monthby-month minimum ecological runoff calculation method and month-by-month frequency calculation method,this article proposed a new method of lake ecological water level calculation.Based on wet year,normal year and dry year which is divided by the annual mean stage with reliability of 37.5% and 62.5%,the month-by-month minimum water level and the monthly mean stage with reliability of 25% and 75% were used to calculate lake minimum ecological water level and optimal ecological water level respectively.The new methods were applied to the Poyang Lake.The results show that it took natural hydrologic regime into account so that it is better to restore the natural water level changes in the process,which provides reference for lake water resources protection.