Optimal Dispatching Of Water Resources In Daquan Reservoir Irrigation Area Of Luhe District

Daquan Reservoir Irrigation Area is located in Zhu Zhen Town,northwest of Luhe District,Nanjing,which has made great contributions to the local economic development.The irrigation area is located in the low-hilly region with complicated terrain including low hills,hilly areas,and plain polder area.Due to topography,climate and other factors,the irrigated area is prone to drought.In some areas,it's even difficult for residents and livestock to have drinking water during special drought years,which has a huge impact on local agriculture.However,the deficits may be huge,if water supply is only dependent on local water resources.Therefore,it's necessary to carry out the joint operation of multiple water sources by water transfer of pumping stations in Daquan Reservoir Irrigation Area.According to the characteristics of water supply and storage in Daquan reservoir irrigation area,the water supply and demand forecast were systematically analyzed and studied as well as optimal operation of water resources;the main research contents and methods were as follows:Three small reservoirs named as Hongshan,Siwu,Wulonggang in the upper reaches of Daquan reservoir were integrated into a generalized reservoir and its water shortage could be replenished from Daquan reservoir.An optimization model of the joint operation of the generalized reservoir,Daquan Reservoir Hongshan pumping station and Xuzhuang pumping station was constructed to minimize the annual pumping cost of the system while water demands were met as much as possible.The constraints included water diversion capacity,maximum pumping capacity,lower and upper bounds of reservoir storage and maximum water demand,etc.According to the yearly mode of water demand in Daquan Reservoir Irrigation Area,the operation cycle was divided into 20 periods;the peak period of water consumption,from June to September were divided by ten days and the rest were divided by the month.The conventional operation simulated the operation process according to the joint operation regulation of reservoirs and pumping stations while the optimal operation adopted Genetic Algorithm(GA)to solving the optimazation model in Matlab.The results were compared with each other;the optimal operation results were almost consistent with that of conventional operation at 75%probability of exceedance,but could reduce the pumping water by 4.8 ± 105m~3 and save 520,00 yuan in the annual pumping cost at 95%probability of exceedance.