流域非点源污染分布式模拟研究

论文选择黄河流域洛河上游卢氏水文站以上作为研究区，构建了水文模型、土壤侵蚀模型、污染负荷模型与RS和GIS耦合的分布式非点源污染模型，以RS和GIS技术为支持，建立研究区空间数据库和属性数据库，为模型模拟提供基础数据.在此基础上，探讨亚流域划分对模型敏感参数的影响，提出亚流域划分的合理水平;分析了DEM分辨率和降雨空间不均匀性对径流、泥沙负荷等模拟结果的影响;采用修正的摩尔斯检验法对模型参数进行了敏感性分析，进而确定非点源污染模拟的最敏感影响参数;在对模型参数进行率定时，按径流成分分别率定，包括直接径流(地表径流和壤中流)和基流;最后对研究区非点源污染物氮、磷的负荷量及其时空分布规律进行了研究，并对农业耕地管理方式及其对非点源污染的影响进行了情景模拟。

This study selects the area above the Lushi Hydrological Station in the upper reaches of the Luo River, Yellow River Basin, as the research area. A distributed non-point source pollution model coupled with RS and GIS technologies is constructed, integrating hydrological model, soil erosion model and pollution load model. Supported by RS and GIS techniques, the spatial database and attribute database of the study area are established to provide basic data for model simulation. On this basis, the impact of sub-watershed division on the model's sensitive parameters is explored, and a reasonable sub-watershed division level is proposed. The impacts of DEM resolution and spatial heterogeneity of rainfall on simulation results such as runoff and sediment load are analyzed. Sensitivity analysis of model parameters is conducted using the modified Morse test, and the most sensitive parameters affecting non-point source pollution simulation are determined. During model calibration, the calibration is carried out according to runoff components, including direct runoff (surface runoff and interflow) and base flow. Finally, the loads and spatio-temporal distribution patterns of non-point source pollutants (nitrogen and phosphorus) in the study area are investigated, and scenario simulations are performed for agricultural cropland management practices and their impacts on non-point source pollution.