Pollution Control & Sustainable Environment

Biography

Biography: Willabo Miepamo

Abstract

This study on aquifer vulnerability assessment in certain parts of Yenagoa, Bayelsa State, Southern Niger Delta, Nigeria, adopted the use of DRASTIC method based on geographic information system (GIS) model to delineate areas susceptible to contamination. Seven hydrogeologic parameters were applied for the aquifer vulnerability evaluations, which include depth to water table, net recharge, soil media, impact of vadose zone, aquifer media, topography, and hydraulic conductivity. Data relating to the seven hydrogeologic parameters of the model were obtained and transformed in the model into seven maps by GIS to develop the DRASTIC vulnerability map which shows the three different forms of aquifer vulnerability namely high, moderate, and low zones. The communities within the high vulnerable zones include Swali, Agudama, Ovum, Igbogene, Okutukutu, Onopa and Okolobiri. Those within the moderate vulnerability zones are Kpansia, Etegwe, Yenezue, Azikoro, Opolo, Tombia, Biogbolo and Akenfa and in the low vulnerability zones, we have Amarata, Yenezuegene, Edepie, Azikoro, Akenfa and Okaka. The high vulnerability zones ranking was attributed to very high depth to water table, high net recharge, high hydraulic conductivity and permeability of gravelly sand in the aquifer media. The moderate vulnerability zones were due to high net recharge, low porosity of silt/clay in vadose zone, silty loam in soil media and high hydraulic conductivity. The low vulnerable zones were influenced by impermeability of clayloam in the soil media, low porosity of silty clay in the vadose zone and low topographic slope percent.