Water resources allocation in Erhai irrigated district considering catchment water-cycle health. Issue 1 (May 2020)

• Record Type: Journal Article
• Authors: Su, Jianguang; Wang, Fei; Gao, Rong; Mi, Zhou; Chen, Jinming; Gu, Shixiang
• Is Part Of: IOP conference series. Volume 508:Issue 1(2020)
• Publication Date: 2020-05
• Subjects: Earth sciences -- Periodicals; Environmental sciences -- Congresses; Environmental sciences -- Periodicals; 550.5
• DOI: 10.1088/1755-1315/508/1/012105
• Languages: English
• ISSNs: 1755-1307

Abstract

Abstract: In order to realize the healthy circulation of Erhai Basin water system, this paper constructs the Mike basin simulation model of Erhai Basin water resource system through the concept of water resource comprehensive allocation. Which is based on the principle of Erhai Lake water ecological environment protection and follows the principle of ecological priority, sanitary water into the lake, double control of total amount and consumption, and water conservation and emission reduction. The results show that agriculture irrigated area of Erhai Basin should be gradually reduced to 472000 mu, and 48200 mu of wetland ecological pool should be increased, which is used as the collection area of basin landscape and irrigation return water. After adjusting the crop planting pattern according to the depth of water saving in Erhai irrigation area, the goal of controlling the agricultural water consumption to be no more than 201 million cubic metre and the total water consumption to be less than 366 million cubic metre should be achieved. The effect of reclaimed water irrigation on water saving and emission reduction is considerable. The application of reclaimed water irrigation can reduce the amount of clean water used in paddy growth period by 46.4%, and the amount of nitrogen fertilizer applied by 30.2%. The replacement rate of garlic reclaimed water can reach 100%. After the comprehensive allocation of water resources, it can supply 501 million cubic metre of ecological water in the river channels and 359 million cubic metre of water out of the river channels. Through the comprehensive utilization project of farmland drainage water and the construction of ecological regulation and storage belt, all irrigation drainage water should be reused and zero discharge can be realized. TN and TP emissions in irrigated area will be reduced by 39.3% and 46.3% respectively. Compared with the current situation, Erhai Lake water inflow and cleanly water inflow increased by 65 million cubic metre and 134 million cubic metre respectively. The annual average water level of the lake will be 0.15m higher than the current situation.