Mapping Ground Water Potential Recharge Zones in Parts of Akwa Ibom State Using Geographic Information System (G.I.S)

Thomas A Harry ,Ekpedeme R Asuaiko ,Nsidibe Akata ,Ndifreke Akpan

doi:10.7176/cer/12-2-08

Abstract

The study was conducted to map ground water potential recharge zones based on physical parameters in southern parts of Akwa Ibom State using Geographical information system (GIS). The aim was to produce ground water recharge potential map for the protection of water quality and the management of ground water systems. Thematic maps of lithology, land cover/ land use, lineaments, drainage, and slope of the study area were produced from various sources. The influence of each factors to groundwater recharge and interaction between the factors were examined and ranks were assigned. Weighting values were assigned according to the degree of the Multiple Influencing Factors (MIF). All the thematic maps or layers were integrated applying weighted overlay analysis in a GIS environment (Arc Map 10.5 software) to produce the resultant map. The study produced a ground water recharge potential map of parts of Akwa Ibom State. The resultant map indicated that the most effective groundwater recharge potential zone was trending in the NW – SE direction. In this region, the coastal plain sands of the Benin Formation, the agricultural land and forest possesses high infiltration ability. Additionally, the concentration of drainage also indicates the ability of stream-flow to recharge the groundwater system. The downstream region is least effective for groundwater recharge, mainly due to its elevation being as low as sea level. Keywords: Mapping, Groundwater, GIS, Lineament, Drainage, Recharge DOI: 10.7176/CER/12-2-08 Publication date: February 29 th 2020

Highlights

Groundwater recharge is the movement of water from the unsaturated zone into the saturated zone below the water table surface, together with the associated flow away from the water table within the saturated zone (Freeze and Cherry 1979)
The land use/ land cover map of the study area was extracted by masking and derived form a 7 band LandsatTM data derived from EARTH EXPLORER, using the image classification tool bar, signatures were selected for the image i.e. areas that are built up and vice versa were reclassified by likelihood and assigned weightage based on influence levels
5.0 CONCLUSION This study has established the interrelationships between the groundwater recharge potential factors and the groundwater recharge potential scores from the general hydrology characteristics of the southern part of Akwa Ibom State

Summary

Introduction

Groundwater recharge is the movement of water from the unsaturated zone into the saturated zone below the water table surface, together with the associated flow away from the water table within the saturated zone (Freeze and Cherry 1979). It is the volume of water that reaches the saturated zone of the aquifer contributing to the replenishing ground water reservoir. It is an extremely important water component of the circulation cycle in nature. Ground water recharge could be a natural or an artificial process. Akintola (1974) classified ground water recharge into actual recharge and potential recharge depending on the infiltrated water that reaches the water table from the recharge, estimated from surface water and unsaturated zone which may reach the water table (actual) and which may not reach the water table (potential)

Methods

Results

Discussion

Conclusion