Study On Water Resources Allocation In The Southwest Of Mengcheng

Mengcheng County s water supply and the "rural drinking water safety project" which is being carried out by the surrounding villages and towns, choose porous confined groundwater as main source of water. Actually, the cone of depression of confined groundwater around the county is becoming larger and the water level keeps declining. In the five towns located in the southwest of Mengcheng County, the surface water and pore phreatic has certain potential utilization and is now mainly used for agricultural irrigation. On the basis of the five towns, according to the basic characteristics of porous confined groundwater, pore phreatic and surface water, combined with users’ demand, this paper focus on water resources optimal allocation.In planning of the year 2015-2020, the domestic water demand forecasted in the area is 8.3097 to 8.6904 million m3/a. Based on the Visual modflow software, groundwater numerical simulation model is established, controlling the downtown of porous confined groundwater in 10 meters, the quantity of exploration forecasted is 5.1465million m3/a and allowable quantity of exploration calculated in the condition that assurance rate of pore phreatic amount to 95% is 5.1465million m3/a. Based on this, according to water source exploiting conditions and water quality conditions, combined with water yield and quality requirement of domestic water, the paper put forward reasonable allocation of porous confined groundwater and pore phreatic.The requirement of agricultural irrigation is respectively 42.6564 to 4.48323 million m3/a in the year of 2015 to 2020. Calculating the available quantity of surface water in the condition of different assurance rate and the available quantity of pore phreatic for agricultural irrigation, then distributing the water for agricultural irrigation.The results show that rational and mode rate exploitation of pore phreatic and porous confined groundwater is able to meet the demand of users in research area on the premise that surface water resources is ultimately used.