Research Of The Groundwater-artificial Lake Water Exchange At The Salt-water Area Of The Dagu River

Water is indispensable for human survival,Groundwater is an important part of water resources.Dagu river groundwater reservoir is an important water source of Qingdao, In the 1980’s as people excessive exploitation of groundwater in the downstream of the Dagu river caused seawater intrusion.In 1998 the establishment of the impervious wall named Mawanzhuang in the south of Le ge zhuang., effectively prevent the seawater intrusion, but also make some residues of saline water in the Le ge zhuang area.Because of the sand mining formed sizes artificial lakes at the same place. The underground salt water-artificial lakes exchange directly affect the evaluation of the water resource total amount and structure and it also affects the distribution of saline groundwater. Further affect the governance of saline groundwate. Depth study of groundwater-artificial lake exchange has very important implications for monitoring groundwater quality and groundwater resources utilization.This article, on the basis of investigation and study of regional natural environment, artificial lakes and groundwater level monitoring network is established. Understand the water level changes of the artificial lakes and groundwater, and master the distribution and change rule of saline groundwater in the study area. Through indoor test calculate seepage meter work efficiency and use it to study the time and space effects on groundwater-artificial lakes interface exchange. Finally, used the water balance calculation to study the artificial lakes -groundwater exchange.The conclusions are as follows:(1) Changes of water level and water quality was understanded.The study results show that the distribution of groundwater level consistent with the terrainand it has Seasonal changs. The lake water level present a steadily rising trend. The seasonal change of salinity is small, and in the vertical salinity stratification was appeard. The salinity of the vertical stratification appear in the small scale of the southern region near the impervious wall. The salinity from southeast to northwest gradually reduced in the horizontal direction.(2)Through the design process and laboratory test, the seepage meter’s working efficiency was obtained.According to the calculation of seepage meter work efficiency in different sand tank seepage velocity the seepage meter efficiency range between 0.83 to 0.95. Finally we calculate seepage flow meter work efficiency was 0.90.(3)The changes of Groundwater-artificial lakes exchange with the time and space was marsted.The results show that on the banks of lake the lake flowed into groundwater, the exchange of artificial lake-groundwater in the dry season is greater than the rainy season and we can also see high intensity rainfall will affect the exchange in a short period of time.(4) By collecting meteorological data and water balance calculation,mastered the relationship of groundwater-artificial lake exchange.According to the calculation we can know that groundwater and artificial lakes water exchange is one of the important reasons for the formation of artificial lake.ln addition, the total recharge of groundwater to the lake in a year is 2.3×105 m3.t he maximum number of groundwater recharge to the lake appear in the August,the value is 46800 m3. Minimum of lakes on the action of groundwater recharge in October, the value is 790 m3.