Investigation On Precipitation Infiltration Coefficient Analysis

Precipitation infiltration coefficient is one of the important factors influencing the evaluation of groundwater resources.It can provide technical support to reasonable development and utilization of water resources planning,set up economic and social development strategy and enhance the sustainable use of water resources and the most strict water resources management.The groundwater has been under a high intensity of mining for more than 30 years.The underground water level is falling and buried depth increasing,the parameters related to the embedded depth of a corresponding change,the original data can not reflect the status quo under the condition of underlying surface water resources condition.Therefore,it is necessary to revise the results of the secondary evaluation of water resources in Hebei province,which is of great theoretical significance and application value.Choosing Hebei plain area as the study area of this research,on the basis of previous research results,considering the change of Underlying surface condition in middle-east plain area,based on the investigation on 167 eyes of 1991 ~ 2015 years monitoring well depth data of underground water and rainfall data of corresponding position,using the dynamic method to calculate the time of the Hebei province in eastern central plain,flood season and annual precipitation infiltration coefficient,based on lithology,categorizing the data,Finally,the relation curves between water infiltration and recharge coefficient and buried depth of different lithology and different precipitation levels are determined.Hydrologic control basin using the water balance method,under the Hengshui city and Cangzhou city cangxian ship the west region of annual precipitation infiltration coefficient is analyzed,using rich data,abundant,flat,dry and other typical years analysis of groundwater balance situation in the study area,area are calculated separately,and the river canal seepage recharge,lateral infiltration recharge,runoff recharge,farmland irrigation,evaporation,and the shallow ground water flow.By means of the formula of water balance,the quantity of rainfall in the region is calculated,and then the coefficient of rainfall infiltration is obtained.Comparing the results of the water balance method and the dynamic method,this paper analyses the coefficient of rainfall infiltration.Summarizing different lithology,precipitation,buried deep under the condition of rainfall infiltration coefficient,compared with the original results,a reasonable trade-off,to check the original coefficient,the analysis of the causes,the comparison results are corrected,eventually to a new time required for water resources evaluation of annual precipitation infiltration coefficient.Finally,compare the results of the water balance method and the dynamic method.The results show that the two methods are relatively close,which indicate that the coefficient of rainfall infiltration is reasonable.The study of the precipitation infiltration coefficient value is slightly smaller than the original "38" the analysis of the results,mainly because of nearly 30 years of Hebei plain vadose zone thickness,lithology,water content,vegetation coverage,planting structure are changed.