Abstract:
The non-point source (NPS) pollution from planting industry is one of the significant causes of water pollution. Identifying the risk areas of NPS pollution helps to allocate the prevention and control resources reasonably and is an important means to prevent NPS pollution effectively. Based on the Minimum Cumulative Resistance (MCR) Model, the spatial pattern identification of NPS pollution risk in the Hetao Irrigation Area was carried out. Based on land use "source" classification, nitrogen/phosphorus emissions, fertilizer application amount, and soil available nitrogen/phosphorus content were selected as source factors, while vegetation cover, soil type, soil structure, rainfall, and distance from water bodies and roads were selected as migration factors. GIS technology was used to identify the "source" areas, construct resistance base, and evaluate the spatial pattern of NPS pollution risk in Wuyuan County, Bayannur, Inner Mongolia. The results showed that nitrogen and phosphorus "source" areas accounted for 11.2% and 2.2% of the study area, respectively. Nitrogen "source" areas were mainly distributed in the towns of Xingongzhong, Bayantaohai, Shengfeng, Longxingchang, and Taerhu; Phosphorus "source" areas were concentrated in Xingongzhong Town. The resistance values of the resistance base in the study area showed a trend of high in the west and low in the east. The key migration factors affecting pollutant loss were rainfall and soil type, with weights of 0.389 and 0.298, respectively. The areas of high, higher, medium, lower, and low risk of NPS pollution from planting industry accounted for 49.7%, 16.9%, 7.8%, 3.5%, and 2.1% of the study area, respectively. The high-risk areas were mainly concentrated in the towns of Bayantaohai, Shengfeng, Longxingchang, and Xingongzhong. The research results show that the risk of NPS pollution from the planting industry in the Hetao Irrigation District is relatively high, and it is urgently necessary to implement comprehensive management through systematic measures such as source reduction and process interception .