SPATIAL DISTRIBUTION OF CARBON DIOXIDE CONCENTRATION FROM INDISCRIMINATE DUMPSITES IN STUDENT RESIDENTIAL AREA OF KWARA STATE UNIVERSITY, MALETE

Abstract

The increasing prevalence of indiscriminate solid waste disposal sites is an alarming environmental concern in
peri-urban and developing student residential communities across Nigeria, particularly because of their
contribution to greenhouse gas emissions. Yet, there are limited studies with explicit and spatial evidence
based on the variability of carbon dioxide (CO₂) concentration levels from these disposal sites. The study
measured CO₂ concentrations at indiscriminate waste disposal sites from the Kwara State University
(KWASU) student residential area to assess spatial variability and distribution using field-based measurement.
CO₂ concentrations were measured at 74 identified indiscriminate waste disposal locations in the study area
using handheld Crowcon Gasman gas detector and benchmarked against 400 pm. The values ranged from 301
to 789 ppm and a mean of 541.7. The data were georeferenced and analysed using Kriging interpolation, focal
point and Getis-Ord Gi* hotspot analysis techniques to determine spatial variation. The result reveals
distinctive spatial variability in the distribution of measured CO₂ concentrations; areas such as Tarmac and
Westend were identified as hotspots of elevated CO₂ concentrations with statistically significant clusters of a
95% and four 90% confidence levels, respectively. The Getis-Ord Gi* analysis map indicates that elevated
concentration levels are not exclusively from decomposition or burning from disposal sites but are influenced
by anthropogenic activities, and GIS-based analysis can effectively identify locations requiring prioritised
environmental management intervention. The study recommends frequent awareness, strategic positioning of
waste collection infrastructures and GIS-based monitoring for early detection to enhance environmental
sustainability.