河南省氮素农业面源污染风险评价与关键管控区识别

农业面源污染是我国水环境保护面临的重要问题，风险评价对于农业面源污染防治具有重要意义。本研究以河南省为研究区域，采用层次分析法的分级赋值方法，基于熵值法和专家打分确定各影响因子权重，构建河南省氮素农业面源污染风险多因子综合评价模型，计算河南省氮素农业面源污染风险指数并在流域尺度上进行验证，划分氮素农业面源污染的风险等级并识别关键管控区。结果表明：种植源、养殖源和生活源分别贡献河南省31.52%、38.47%和30.01%的氮素流失负荷，流失负荷呈现为西低，中、东部高的特点。河南省有39 429 km²的区域存在中风险，约占河南省总面积的23.61%,有17 318 km²的区域存在高风险，约占总面积的10.37%;划定距河流2 km以内的中、高风险区为一般管控区和重点管控区，面积分别为10 982 km²和9 285 km²。通过与同期水质自动监测数据进行相关分析，决定系数为0.82,表明模型模拟结果具有较高的精准度。综合结果表明，建立的多因子综合评价模型具有科学性和准确性，可用于氮素农业面源污染风...

Risk Assessment of Nitrogen Agricultural Non-point Source Pollution and Identification of Critical Control Areas in Henan Province

Agricultural non-point source pollution is an important problem for water environmental protection in China, and risk assessment is of great significance for the prevention and control of agricultural non-point source pollution. Taking Henan Province as the research area, a multi factor comprehensive evaluation model for nitrogen agricultural non-point source pollution was constructed, the hierarchical assignment method of Analytic Hierarchy Process was used, the weights of each influencing factor were determined based on entropy method and expert scoring, the risk index of nitrogen agricultural non-point source pollution in Henan Province was calculated, and it was verified at the basin scale. The risk level of nitrogen agricultural non-point source pollution was divided and critical control areas were identified. The results showed that planting, breeding and domestic sources contributed 31.52%, 38.47% and 30.01% of the nitrogen loss load, respectively. The nitrogen loss load was low in the west and high in the middle and east of Henan Province. In Henan Province, 39.429km2 area was at moderate risk, accounting for 23.61% of the total area of Henan Province, and 17.318km2 area was at high risk, accounting for 10.37% of the total area of Henan Province. The medium and high-risk zones within 2km from the river were classified as general control areas and key control areas, with the general control area of 10.982km2 and the key control area of 9.285km2. Correlation analysis was carried out between the model and the data of automatic water quality monitoring stations in Henan Province in 2021 at the basin scale, and the fitting degree R2=0.82, indicating that the model had a high accuracy. The results showed that the multi-factor comprehensive evaluation model established was scientific and accurate, which can be used for the identification of nitrogen agricultural non-point source pollution.