Use of GIS to Estimate Recharge and Identification of Potential Groundwater Recharge Zones in the Karstic Aquifers,West of Iran

Estimating and studying groundwater recharge is necessary and important for the management of water resources.The main aim of this work is to estimate the value of the annual recharge in some parts of the Kermanshah and Kurdistan province located in the west of Iran.There are many ap­proaches available for estimation of the recharge,but RS(remote sensing)and GIS(geographic information system)have provided and combined a lot of effective spatial and temporal data of large areas within a short time.For this purpose,nine information layers including the slope,aspect of slope,lithology,lineament density,drainage density,precipitation,vege­tation density,soil cover,and karst features were prepared and imported to the ArcMap software.After preparing the information layers,they have to weigh based on their effects on the value of the recharge.In order to be weighted the different parameters,methods of judgment expert,reciprocal influences of parameters,and AHP were used.Using GIS,the results ob­tained from the final map indicated the average value for the recharge based on the average calculated coefficient of recharge.The annual recharge coef­ficient in the study area was estimated to be between 30%and 80%.

Effective groundwater level recovery from mining reduction: Case study of Baoding and Shijiazhuang Plain area

The effective recovery of water level is a crucial measure of the success of comprehensive groundwater over-exploitation management actions in North China.However,traditional evaluation method do not directly capture the relationship between mining and other equilibrium elements.This study presents an innovative evaluation method to assess the water level recovery resulting from mining reduction based on the relationship between variation in exploitation and recharge.Firstly,the recharge variability of source and sink terms for both the base year and evaluation year is calculated and the coefficient of recharge variationβis introduced,which is then used to calculate the effective mining reduction and solve the water level recovery value caused by the effective mining reduction,and finally the water level recovery contribution by mining reduction is calculated by combining with the actual volume of mining reduction in the evaluation area.This research focuses on Baoding and Shijiazhuang Plain area,which share similar hydrogeological conditions but vary in groundwater exploitation and utilization.As the effect of groundwater level recovery with mining reduction was evaluated in these two areas as case study.In 2018,the results showed an effective water level recovery of 0.17 m and 0.13 m in the shallow groundwater of Shijiazhuang and Baoding Plain areas,respectively.The contributions of recovery from mining reduction were 76%and 57.98%for these two areas,respectively.It was notable that the water level recovery was most prominent in the foothill plain regions.From the evaluation results,it is evident that water level recovery depends not only on the intensity of groundwater mining reduction,but also on its effectiveness.The value of water level recovery alone cannot accurately indicate the intensity of mining reduction,as recharge variation significantly influences water level changes.Therefore,in practice,it is crucial to comprehensively assess the impact of mining reduction on water level recovery by combining the coefficient of recharge variation with the contribution of water level recovery from mining reduction.This integrated approach provide a more reasonable and scientifically supported basis,offering essential data support for groundwater management and conservation.To improve the accuracy and reliability of evaluation results,future work will focus on the standardizing and normalizing raw data processing.