基于水文学方法的珠江流域生态流量研究

珠江流域水资源丰富,但由于水体污染等原因,水质性缺水问题较为突出,区域水环境、水生态以及水安全等成为急需解决的重要科学问题。开展生态流量研究对于评价地表水文过程演变对区域水环境与水生态的影响具有重要理论意义,并为区域水资源优化配置和可持续开发利用提供科学依据。基于此,运用各种＂水文学＂方法（包括最小月平均流量法、改进的7Q10法、NGPRP法、逐月最小生态径流计算法和逐月频率计算法）对珠江流域11个主要水文控制站点的实测月径流量做了全面而系统的研究,分析珠江流域生态径流过程,并通过与Tennant法对比分析,选择逐月最小生态径流计算法和逐月频率计算法分别计算了各水文控制站的最小生态径流量和适宜生态径流量,除个别站点外,其评价结果分别处于Tennant法＂中＂和＂最佳＂的等级。对于逐月频率计算法中保证率的选取方法,研究表明各月径流系列均取50%最适合珠江流域。研究同时为仅利用水文资料中的多年逐月径流数据来确定生态需水提供了一种新的研究思路。

Evaluation of ecological instreamf flow of the Pearl River basin,south China

The Pearl River basin is characterized by abundant water resources.However water shortage due to degraded water quality is still serious.Altered hydrological cycle due to climate changes may cause alterations of hydrological processes and which has the potential to negatively influence the ecological environment of the Pearl River basin.Better understanding of ecological inflow streamflow is the first step into the scientific conservation of the water and ecological environment.Besides,the results of the study could be the scientific ground for the allocation and sustainable development and utilization of water resources in an effective way.In this paper,the measured monthly runoff data at 11 major hydrological stations are analyzed to evaluate ecological instream flows of the Pearl River Basin and six hydrological methodologies（the minimum monthly average flow method,the improved 7Q10 method,NGPRP method,the monthly minimum ecological runoff calculation method,the monthly frequency calculation method） are used to estimate ecological runoff.Then the rationality of the calculated results by these methods is analyzed by use of the Tennant method.As a result,the monthly minimum ecological runoff calculation method and the monthly frequency calculation method are chosen to calculate minimum ecological runoff and optimal ecological runoff respectively.And the results almost match the medium or optimum ranges of those calculated with Tennant method apart from individual station.In the monthly frequency calculation method,we need to determine an appropriate guaranteed rate;this study shows that taking 50% guaranteed rate for every month＇s runoff in many years is the most suitable in the Pearl River Basin.Meanwhile,a new approach is introduced to calculate ecological water requirement by only using monthly runoff data.