Evaluation Of The Water Quality Of Tuo River On The Water Source Area In Suzhou City

The Tuo river is located in the west of Suzhou city.For a long time,the river has been polluted because of the sewage from the cities in the upper reaches.Groundwater has been polluted.The water source of Suzhou city is located on the west bank of the Tuo River,with the nearest distance from the Tuo River less than 1km.Over-extraction of groundwater is expected to cause the groundwater depression cone.However,effects of river water quality on water source is still unknown.The work investigated the characteristics of groundwater flow and quality by using groundwater modeling,and evaluate effect of the Tuohe River quality on groundwater source,which provide a scientific basis for the construction and development of the water source area in the city.The paper has fully collected the information about the basic geology,hydrogeology,the construction of the water source land in the development zone and the discharge enterprises in the development zone.Through the data collection,analysis,research and numerical simulation,the pollution status of the water in the Tuo River and the development zone is basically ascertained,and the Tuo river may be made up the pollution problem of water sources in the development zone has been evaluated,and the purpose of this study has been achieved.The major results are shown as follows.1.The water quality of Tuo river is seriously polluted,and the groundwater nearby has been polluted to various degrees.The pollution of shallow groundwater is especially serious.2.The water level of Tuoriver is lower than the groundwater level.The influence of water quality on groundwater is mainly foundnear the Tuo river bank,which causes pollution ofshallow aquifer.3.Numerical simulation is used to simulate fluctuation of water table under water source mining.Results showed that groundwater abstraction accelerated the rechargeof the Tuo River sewage into the shallow aquifer,which has a serious effect on groundwater quality.4.There is a weak permeable layer between shallow and deep aquifers in the groundwater source area,which is stable and thick.Hydraulically,the shallow aquifers are not closely connected with the deep aquifers.Therefore,groundwater in deep aquifers would be the safe water source for the city.The shallow water should not be exploited within 500-1000 maway fromthe Tuo River,and the mixing extraction from shallow and deep aquifers is strictly forbidden.