Arid Zone Research ›› 2022, Vol. 39 ›› Issue (2): 625-637.doi: 10.13866/j.azr.2022.02.29

• Ecology and Environment • Previous Articles     Next Articles

Response of agricultural nonpoint source pollution load in the Ulungur River basin under climate change

ZOU Kaibo1(),ZHANG Yuhu1(),LIU Xiaowei2,XUE Shuhui1,YANG Bowen1,CUI Yanxin1   

  1. 1. College of Resources Environment and Tourism, Capital Normal University, Beijing 100048, China
    2. South China Institute of Environmental Science, Ministry of Ecology and Environment, Guangzhou 510530, Guangdong, China
  • Received:2021-05-21 Revised:2021-08-20 Online:2022-03-15 Published:2022-03-30
  • Contact: Yuhu ZHANG E-mail:zou_kaibo@163.com;zhang_yuhu@163.com

Abstract:

Taking the Ulungur River basin in Xinjiang as study area, a nonpoint source pollution distributed hydrological model suitable for the basin was constructed based on the soil and water assessment tool (SWAT), and nine climate change scenarios were set using the scenario setting method. The impact of different climate change scenarios on the river basin runoff and nonpoint source pollution load was analyzed, key affected areas were identified, and a scientific basis for the prevention and control of nonpoint source pollution in the river basin was provided. The results show that (1) the values of the determination coefficient R2 for runoff, total nitrogen and total phosphorus in the regular rate and verification period were all above 0.75, and the Nash coefficient Ens was above 0.55. The established SWAT model could be used for agricultural nonpoint sources in the pollution load simulation applied to the Ulungur watershed. (2) Precipitation, runoff, total nitrogen load, and total phosphorus increased by 20%, 48.01%, 23.19%, and 29.65%, respectively, and the impact on runoff caused by temperature variation was less than that caused by precipitation variation. (3) The average annual total nitrogen load per unit area of each sub-catchment was between 0.01-164.79 kg·hm-2·a-1, and the total phosphorus load per unit area was between 0.01-45.10 kg·hm-2·a-1. The areas where climate change had a greater impact on nonpoint source pollution were mainly distributed in Arda Township in Fuhai County, Turhong Township, Kuerte Township, and Chakurtu Township in Fuyun County, Arele Township, Altobe Town, and Takshken Town, etc. in Qinghe County. Studies have shown that increased precipitation is one of the main factors affecting the agricultural nonpoint source pollution load in the basin. In the future, the prevention and control of this type of pollution should focus on controlling two types of pollution sources, livestock and poultry breeding and farmland runoff.

Key words: climate change, SWAT model, Ulungur River basin, nonpoint source pollution