The combined use of MODFLOW and precipitation-runoff modeling to simulate groundwater flow in a diffuse-pollution prone watershed

摘要

A numerical modeling case study of groundwater flow in a diffuse pollution prone area isnpresented. The study area is located within the metropolitan borders of the city of Izmir, Turkey.nThis groundwater flow model was unconventional in the application since the groundwaternrecharge parameter in the model was estimated using a lumped, transient water-budget basednprecipitation-runoff model that was executed independent of the groundwater flow model. Thenrecharge rate obtained from the calibrated precipitation-runoff model was used as input to thengroundwater flow model, which was eventually calibrated to measured water table elevations.nOverall, the flow model results were consistent with field observations and model statistics werensatisfactory. Water budget results of the model revealed that groundwater recharge comprisednabout 20% of the total water input for the entire study area. Recharge was the second largestncomponent in the budget after leakage from streams into the subsurface. It was concluded thatnthe modeling results can be further used as input for contaminant transport modeling studies innorder to evaluate the vulnerability of water resources of the study area to diffuse pollution.