湘粤交界山区性河流生态流量确定方法研究

Research on the Determination Method of Ecological Flow of Mountain Rivers at the Border of Hunan and Guangdong Province

摘要: 生态流量是维系河流生态系统健康的核心要素。武江坪石水文站作为湘粤跨省流域的关键控制节点，处于湘粤边境岭南生态屏障带，其生态流量的科学确定对区域水资源协同管理具有重要意义。本文基于坪石站1956~2021年逐月流量数据，在全面分析坪石站径流量年际及年内变化特性基础上，采用近10年最枯月均流量法、Q_p法(设计保证率最枯月平均流量法)、Tennant法(河流最小月平均实测流量法)和逐月平均流量频率曲线法等水文定量分析方法，开展多方法对比研究。结果表明：不同方法计算的枯水期生态流量值为8.5~10.9 m³/s，其中Q_p法与Tennant法因兼具理论严谨性与操作可行性，更适用于本流域管理实践；研究结果与《北江流域生态流量保障方案》的10 m³/s控制目标高度契合，可为华南山区性河流生态流量精细化管理提供技术支撑。

Abstract: Ecological flow is a core element in maintaining the health of river ecosystems. The Wujiang Pingshi Hydrologic Station, as a key control node in the cross provincial watershed of Hunan and Guangdong provinces, is located in the Lingnan ecological barrier zone on the Hunan Guangdong border. The scientific determination of its ecological flow is of great significance for the coordinated management of regional water resources. Based on the monthly flow data of Pingshi Station from 1956 to 2021, this article took comprehensive analysis of the interannual and intra-annual variation characteristics of the runoff at Pingshi Station, and multiple hydrological quantitative analysis methods such as the driest month flow method, Q_p method (design guarantee rate driest month average flow method), Tennant method (minimum monthly average measured flow method of rivers), and monthly flow frequency curve method were used to conduct comparative research. The results showed that the ecological flow threshold during the dry season calculated by different methods ranged from 8.5 to 10.9 m³/s. Among them, the Q_p method and Tennant method were more suitable for the management practice of this watershed due to their theoretical rigor and operational feasibility; The research results are highly consistent with the 10 m³/s control target of the “Beijiang River Ecological Flow Guarantee Plan”, which can provide technical support for the fine management of ecological flow in mountainous rivers in South China.