Numerical Simulation Study Of Groundwater In Guantao Based On Visual MODFLOW

Guantao County is located in the eastern part of Handan City,Hebei province,which belongs to the Zhangwei South Canal system of Haihe River Basin.The surface water and groundwater resources of this area are relatively scarce and the Wei Canal of this territory often dries up.In recent years,the water level has dropped seriously and more than one funnel area formed because of the large-scale over mining of the groundwater.So it has an important guiding significance for scientific evaluation of groundwater resources to correctly construct the groundwater dynamic numerical model in this area and carry on the numerical simulation prediction with groundwater exploitation.Firstly,according to the geological conditions and the hydrogeological conditions of the study area,the stratigraphic lithology and geological structure of the aquifer were determined,the recharge,runoff,discharge characteristics and dynamic features of groundwater were expounded.The hydrogeological conceptual model of the study area was established.Besides,the hydrogeological parameters partitioning was determined in the light of the the field drilling information and the empirical values.According to the hydrogeological conditions,river system distribution and rainfall evaporation characteristics,this paper ascertained the model boundary conditions and source sinks.On the basis of the above,a non-homogeneous isotropic two-dimensional unsteady flow model was established,which was solved by Visual MODFLOW software.Three water-level observation wells in the area were chosen for model identification and verification based on the observed data of groundwater level from January 2010 to December 2011.Rely on the regional hydrogeological drilling data and field measured vertical infiltration coefficient,the actual permeability coefficient,specific yield and other key parameters were finally determined.And the analysis of water balance make clear that the rainfall infiltration is the main recharge source of shallow groundwater in the research area.The forecast period of the model is from January 2015 to December 2015.And the result indicates that groundwater exploitation has not been significantly moderated because the water level flow field in 2015 presents a slow downward trend compared with 2010.But from 2015 to 2019,the underground water level reaches a new dynamic balance because there is no obvious change in the groundwater flow field.But from 2019 to 2024,the groundwater level shows a weak upward trend,groundwater recharge is greater than excretion,therefore,the research area is in the positive equilibrium.