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This paper adopts the maximum carrying population, industrial added value and agricultural irrigation area to develop a multi-objective model of water resources carrying capacity (WRCC) in Dianchi-Pudu river basin. The model is used to calculate the WRCC for Dianchi-Pudu river basin in 2020 and 2030 respectively in terms of three different water supply schemes. Results show that except Scheme III which can basically support future socio-economic development and population increase, both Scheme I and II cannot support future socio-economic development and population increase of Dianchi-Pudu river basin. Interbasin water transfer would greatly increase the WRCC of Dianchi-Pudu river basin while efficient water saving can merely work in a limited extent. Consequently, interbasin water transfer and efficient water-saving are the necessaries to guarantee the positive balance between the exploitation of water resource and socio-economic development of Dianchi-Pudu river basin.

Water resources carrying capacity (WRCC) assessment is an effective way to evaluate the coordinated development of water resources, economic society and ecological environment, thus, it is significant to study WRCC to realize the harmony among water resources, economy and society in region. In this paper, an index system for evaluating WRCC, which represents the natural attributes and the managerial attributes of water resource, was constructed. Moreover, the T-S Fuzzy Neural Network Model was applied to evaluate WRCC of resource-oriented, management-oriented and comprehensive in Dali Prefecture, respectively. The results showed that evaluation results of WRCC of resource-oriented, management-oriented and comprehensive were different from each other obviously. Evaluation results of comprehensive WRCC accords with the fact. The WRCC in research region was averaged overall. WRCC in Heqing county, Eryuan county, Yangbi county, Dali city, Binchuan county, Xiangyun county and north of Midu county and Weishan county was already in a critical status, but that in the other area of Dali Prefecture was in non-overloading status.

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.