Research On The Transformation Between Surface Water And Groundwater Based On Environmental Isotopes In The Yubei Plain

Yubei plain is a important industrial and grain region in Henan province.The fluctuation of surface water and groundwater,especially at the over-ground section of Yellow River,is related to the development of social economy and ecology.Therefore,the research on the transformation between surface water and groundwater in the Yubei plain is particularly important.In this research,groundwater dynamic field method,environmental isotope method and hydrogeochemistry method were used to conduct qualitative research on the transformation of surface water and groundwater based on the local conditions of geography,geological and hydrogeological.The groundwater dynamic field method has preliminarily explored the transformation of surface water and groundwater.The environmental isotope method has further improved the accuracy of the research.Hydrogeochemical method is the verification of the environmental isotope method.The research analyzed the recharge source and formation environment of surface water and groundwater by using the isotopic composition of deuterium and oxygen of water samples.The influence zone of the Yellow River and the shallow groundwater equilibrium zone is accurately divided by observing the distribution characteristics of isotopes along Xinxiang-Zhongmu section.The proportion of recharge of Yellow River to groundwater was calculated by using isotope mass balance theory.The age of groundwater was determined by radioactive tritium.All these studies have promoted the understanding of the transfoamation of surface water and groundwater inYubei plain.The research shows that:(1)The water supply capacity of the Yellow River on the north bank is greater than that of the south bank.The influence zone of the Yellow River is divided into the strong influence zone and the farthest influence zone in the horizontal direction.The strong influence zone on the north bank of the Yellow River is at least 8.5km,the farthest influence zone reaches as far as 22 km,and the strong influence zone on the south bank is at least 3.4km,and the furthest influence zone reaches as far as 10 km.The influence zone of the Yellow River can reach 100 m in the vertical direction,including shallow aquifer.During the period of setting off,there is no recharge of Yellow River to groundwater.After the completion of xiaolangdi reservoir,the setting off of Yellow River has never happened again,and the influence zone of the Yellow River has been stable.(2)Both surface water and groundwater are traced back to atmospheric precipitation.The recharge source of the Yellow River is the upstream incoming water and the atmospheric precipitation along the river path.The shallow groundwater is from the infiltration of atmospheric precipitation and the side seepage of the Yellow River.Middle ground water is from atmospheric precipitation before the nuclear explosion,and some areas also accept shallow groundwater recharge.Deep groundwater is from the atmospheric precipitation in the Pleistocene period,which the climate is cooler and drier.