Expected spatio-temporal variation of groundwater deficit by integrating groundwater modeling, remote sensing, and GIS techniques

Abstract

For the last 6 decades, the Nile Valley region has been subjected to expanding reclamation, advancing agricultural and human activities. Extreme changes in the groundwater regime and land cover have been detected. Evaluation and mapping of groundwater and its controlling factors as important environmental factors have been assessed and managed based on their Spatio-temporal distribution and effect on the hydrologic properties. Visual MODFLOW and GIS database modeling are applied to simulate and predict the future aquifer response due to increased pumping rates to match the continuous need for water resources. Two pumping scenarios are proposed. The first scenario assumes that the current extraction rates continue without modification over the next 50 years. The second scenario assumes to increase the pumping rates by 50% from those of the first scenario. An obvious decline in groundwater heads is resulting in both scenarios. It reaches 20 m in the first scenario while it exceeds 30 m in the second one. Results obtained from the model have been merged with remote sensing data under GIS framework. GIS model using the weighted overlay approach is applied to produce the groundwater potentiality map, classified to five potential zones; very good, good, intermediate, poor, and very poor, the model showed that zone of very good recharge will decrease with time and disappear with increase pumping rate by 50% while the poor and very poor zones increase with time. There is a reciprocal relationship between the human and geological factors on the efficiency of the aquifer.