State Key Laboratory of Resources and Environmental Information System, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, 100101, China; CAS Engineering Laboratory for Yellow River Delta Modern Agriculture, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, 100101, China.
State Key Laboratory of Resources and Environmental Information System, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, 100101, China.
Environ Pollut. 2022 Nov 1;312:120036. doi: 10.1016/j.envpol.2022.120036. Epub 2022 Aug 28.
Agricultural non-point source pollution (AGNPSP) is an important risk factor affecting the water environment. Among the areas where cropland NPSP occurs, the coastal zone should be of greater concern. Typhoons, heavy precipitation, and abundant rivers and ponds accelerate the transport process of AGNPSP to the offshore waters. It is urgent to construct a simple and accurate model to assess the risk of AGNPSP in the coastal zones. Thus, this study takes the nitrogen pollution from agricultural cultivation in the coastal zone of the Yellow River Delta as an example. A new minimum cumulative resistance (MCR) to agricultural non-point source pollution (AGNPSP-MCR) model is first proposed to simulate the transport process of cropland NPSP into the sea based on the "source-sink" theory in landscape ecology. Finally, the risk is assessed for AGNPSP transport into the sea. The results show the following. (1) The environmental factors of vegetation cover, rainfall erosivity, and soil erodibility are the three most important factors in pollution transportation, weighted 0.3433, 0.2608, and 0.2219, respectively, while the least influential factor is slope, with a weight of only 0.0053. (2) The minimum cumulative resistance of AGNPSP transportation shows a significant positive correlation with the distance to the river and sea, and is higher on the west sides away from the ocean, and smaller in the eastern coastal area near the sea. (3) Similarly, the regions facing serious AGNPSP risk are concentrated in the eastern coastal area, and the cropland area above medium risk was 252.72 km, accounting for 47.57% of the total cultivated land area. (4) Compared with the traditional MCR model, the AGNPSP-MCR model takes into account the quantitative differences of the transport process characteristics of AGNPSP, and it is constrained by the topographical parameter, so the results of AGNPSP risk are more reliable. This study provides a new reference for risk assessments of AGNPSP in the coastal zones.
农业面源污染（AGNPSP）是影响水环境的一个重要风险因素。在发生农田 NPSP 的地区中，沿海地区应引起更大的关注。台风、强降水以及丰富的河流和池塘加速了 AGNPSP 向近海水域的输送过程。因此，迫切需要构建一个简单而准确的模型来评估沿海地区 AGNPSP 的风险。因此，本研究以黄河三角洲沿海地区的农业种植氮污染为例。首次提出了一种新的最小累积阻力（MCR）农业非点源污染（AGNPSP-MCR）模型，该模型基于景观生态学中的“源-汇”理论，模拟农田 NPSP 向海洋输送的过程。最后，评估了 AGNPSP 向海洋输送的风险。结果表明：（1）植被覆盖、降雨侵蚀力和土壤可蚀性这三个环境因素是污染传输的三个最重要因素，权重分别为 0.3433、0.2608 和 0.2219，而影响最小的因素是坡度，权重仅为 0.0053。（2）AGNPSP 运输的最小累积阻力与距河流和海洋的距离呈显著正相关，远离海洋的西侧较高，靠近海洋的东部沿海地区较小。（3）同样，面临严重 AGNPSP 风险的地区集中在东部沿海地区，中高风险的耕地面积为 252.72km²，占总耕地面积的 47.57%。（4）与传统的 MCR 模型相比，AGNPSP-MCR 模型考虑了 AGNPSP 传输过程特征的定量差异，并受地形参数的约束，因此 AGNPSP 风险的结果更加可靠。本研究为沿海地区 AGNPSP 风险评估提供了新的参考。
