Study On Rational Exploitation Scheme Of Riverside Well Field In Yaojia Village,Dehui

The water supply in riverside well field is stable and this way for exploitation and utilization of groundwater,which becomes important in China,has a certain purification effect on surface water quality.The riverside well field in Yaojia village is located along the coast of the Second Songhua River in Dehui,and is the water supply source for the production base in Dehui of Dacheng Biochemical Technology Group.Most pumping wells in this well field are located far away from the river.It results that groundwater cannot be recharged in time and water table declines quickly in the center of the groundwater depression cone while pumping.In addition,some pumping wells are concentratedly distributed,which leads to serious interference.The reduced groundwater yield couldn't meet the demand of water for production and domestic use.Based on the analysis of geological and hydrogeological conditions of the riverside well field in Yaojia village,the hydrodynamic research method,environmental isotope tracing method and heat tracing method were used together to reflect the flux of river infiltration,and a numerical simulation model of groundwater flow was established to evaluate groundwater resources.In order to secure water demand and ensure the sustainable exploitation of groundwater,the layouts of pumping wells were designed;a groundwater management model was established,and a rational layout of pumping wells was chosen for the purpose of expanding groundwater exploitation;and then the exploitation capacity of the riverside well field was determined.The main conclusions of this paper are as follows.1.There is a close hydraulic connection between river and groundwater in riparian zone in the study area.River infiltration is the main recharge of groundwater,and the proportion of river infiltration recharge is about 56.5%.The flux of river infiltration recharge with heat tracing method is between 0.03 m/d to 0.3 m/d.2.The rational layout of pumping wells:select 16 wells from the original pumping wells for making them distribute as evenly as possible,and then add 8 wells in the empty area along the river bank with the distance of 200 m between the river and the distance of 220 m among wells.3.According to the rational layout of pumping wells,the largest groundwater exploitation of the riverside well field could reach to 69600 m~3/d,61320 m~3/d and53600 m~3/d respectively in high,normal and low flow years.And water demand(about 48000 m~3/d)could be met.River infiltration recharge only accounts for 0.10%of the river runoff in the study area.The recharge of the Second Songhua River to groundwater is adequate and stable.Water supply is guaranteed.And the river is safe and stable.The efficient,safe and rational use of groundwater resources in the riverside well field could be realized.