Geospatial and Statistical Evidence of Non-Engineered Landfill Leachate Effects on Groundwater Quality in an Urbanised Area of Nigeria

Abstract

Using GIS technologies and linear regression models, this study explores the subsurface flow and pollution of Ilorin's groundwater system. The Geographic Information System (GIS) was utilized to visualize the direction of groundwater flow and the spread of pollutants within the study area. Water sample stations were explored in the vicinity of big non-engineered ancient dumpsites, and the data were analyzed using principal component analysis and Pearson correlation analysis. A regression model was also created with the goal of determining and quantifying functional correlations between groundwater quality and hypothetical landfill parameters that are expected to affect groundwater pollution. Conductivity, suspended particles, calcium hardness, total dissolved solids, total coliforms, and coliforms were the main contamination indicators, according to the Principal Component Analysis. For many of the metrics studied, Pearson correlation demonstrated a substantial correlation of electrical conductivity. The graphs with simulated values for all outputs were used to validate all of the models developed. The research area's remotely sensed map shows a higher population density and pollution in the south-western part of the area. Similarly, groundwater dynamics representations show water flowing from the north to the south, with the subterranean watershed and recharge containing the highest concentration of chemical contaminants. Finally, the geographic representation of pollution in the groundwater system reveals that locations with low permeability have higher dissolved chemical content concentrations