基于BHM-EcoFlow模型的汉江中下游河段水文-生态响应关系研究

Hydro-ecological response in lower-middle Hanjiang River based on BHM-EcoFlow model

河流水文-生态响应关系是确定生态流量阈值的科学基础。针对当前河流水文-生态响应关系研究中生态数据不足且生态建模难度大的问题,建立了基于贝叶斯层次分析法的BHM-EcoFlow(Bayesian hierarchical modelling-ecological flow)模型,该模型将河流不同河段及同一河段不同站点间的先验知识与实测数据相结合,可有效利用短系列数据,实现河流水文-生态响应关系的模拟。采用汉江中下游干流2011年的水文、生态数据,模拟了浮游植物细胞密度与流量、混合层温度间的关系,计算了不同流量条件下各河段的浮游植物密度。结果表明:BHM-EcoFlow模型提高了短系列数据的可用性,对汉江中下游干流的水文-生态响应关系具有良好的识别能力,为确定生态流量提供了科学依据。

The hydro-ecological response of rivers is crucial for determining ecological flow thresholds.To address the issues of lack of ecological data and challenges of ecological modeling in current research,the BHM-EcoFlow(Bayesian hierarchical modelling-ecological flow)model is introduced.Based on the prior knowledge and measured data from different river sections and different stations in the same river section,this model is able to simulate the hydro-ecological response of the entire river,due to the effective utilization of short-series data.Then,a case study of the mainstream of the lower-middle Hanjiang River in the year of 2011 is conducted to discuss the relationship between phytoplankton cell density,flow rate,and mixed layer temperature.In addition,the phytoplankton cell density in each river section under various flow conditions is further calculated.The results show that the BHM-EcoFlow model improves the applicability of short-series data and demonstrates a strong ability to identify complex hydro-ecological responses in the lower-middle Hanjiang River.This study can provide a technical support for the further calculation of environmental flow rate.