基于水文模拟计算山区小水电站减脱水河段生态需水量的水文学方法及静水域生态补水机制

绝大多数山区小型河流水文观测匮乏,无法直接对水文资料进行统计分析,应用水文学方法计算其河流生态需水量。本研究应用二参数月水量平衡模型,还原广东省博罗县小金河1981-2010年天然月径流过程,然后采用几种常用的水文学方法计算其最小生态需水流量,从而为无资料(或资料匮乏)地区应用水文学方法进行河道生态需水研究提供一种思路。综合考虑山区小型河道水生生物生命周期的特征、生境条件和小水电站的发电效益,提出了基于水量而非流量的"静水域生态补水机制",以维持小水电站减脱水河段的最小生态需水量。作为河流生态流量的一种替代,小水电站减脱水河段的"静水域生态补水机制",可以兼顾河流生态系统的健康和水资源优化综合利用。

Apply hydrological model to evaluation of ecological water demand of dehydration river reaches for small hydropower plants and water supplement

Along most small mountainous rivers, hydrological observation is very poor or completely lacking. It is impossible to estimate their ecological water demand using traditional hydrological methods that directly analyze river hydrological observation data. Xiaojin is a small river with a drainage area 33km2 located in Boluo county of Guangdong province, and along its mainstream seven small hydropower plants were developed in the past half century. In this work, a monthly water balance model with two parameters was adopted to recover the past flow processes in the Xiaojin River for the period of 1980-2011. Then, several traditional hydrological methods were applied to calculation of river ecological water demand. This provides a strategy for study of ecological water demands by the ungauged (or data-poor) mountainous regions. This paper describes a strategy of minimum water supplement based on water volume rather than flow rate, named sustainable static water areas for river ecology, which considers the life cycle characteristics of aquatic lives, their habitat conditions, and the benefits of hydropower stations on small mountainous rivers. By applying this conceptualization, river ecology and hydropower development can be well balanced in hydrological and hydraulic evaluation of minimum ecological water demands.