水库库湾水质时空变异及其对景观背景的响应

Reservoir bay is the sensitive area of water quality in drinking water reservoirs. The watershed of a reservoir bay is the direct source of water pollutants. Watershed landscape including topography, soil and land use profoundly influences water quality of reservoir bays. Understanding the specific responding mechanism of spatial and seasonal variability in water quality within reservoir bay to neighbourhood landscape, has considerable importance for exploring water quality evolution. In this study, we select typical reservoir bays with different landscape of the Danjiangkou Reservoir, which is the water source for the Middle Route Project under the South-to-North Water Transfer Scheme of China. Continuous monitoring of water quality, landscape survey and spatial pattern analysis will be combined for studying the response process of water quality dynamics within reservoir bay to neighbourhood landscape by the impact of reservoir hydrological rhythm, and revealing the coupling mechanism between spatial and seasonal variability in water quality and landscape. The research results will be beneficial to water quality protection for drinking water reservoirs.

库湾是水库型水源地水质安全的敏感区，库湾汇水区域作为其污染物的直接来源，地形、土壤、土地利用等景观背景深刻影响库湾水质。理解水库反季节水文节律下库湾水质时空变异及其对景观背景的响应机制，对揭示水库型水源地水质演变规律具有重要科学意义。本项目选择南水北调中线工程水源地——丹江口水库不同景观背景的典型库湾为研究对象，通过库湾水质定点连续监测，研究水库反季节水文节律下的库湾水质时空变化规律；基于库湾景观背景调查及其空间格局分析，研究水库反季节水文节律下库湾水质动态变化对景观背景的响应过程，揭示库湾水质时空变异与景观背景的内在耦合机制，为水库型水源地水质安全保护提供科学依据。

本项目遴选了丹江口水库62个不同类型的典型库湾作为重点研究对象，通过在每年丰水期和枯水期分别对库湾及主要入库支流进行野外调查和定点采样监测，阐明了不同库湾的水质时空变化特征，定量分析了库湾汇水区的土壤、地形地貌、土地利用、景观格局分布状况，评估了库湾富营养化状况和面源污染风险并识别了其主要影响因素。通过构建库湾汇水区环境特征变量（地形形态变量、土壤变量、土地利用组成）和景观格局指数与不同季节库湾水质的偏最小二乘回归模型，定量分析了水库反季节水文节律影响下库湾水质时空变异与环境背景的响应关系，明确了影响库湾水质变化的关键环境背景要素。本研究完成了计划的工作内容，依托本项目培养硕士研究生1名。