Impacts of climate variability on hand-dug wells and boreholes in Lokoja, Kogi State

Abstract

The growing concerns about the effects of climate variability on groundwater resources in semi-urban areas of Nigeria, where dependence on shallow and deep aquifers is critical for domestic and agricultural use. The study aimed to examine how variations in rainfall, temperature, and evaporation influence groundwater quantity and quality, and to evaluate the adaptive responses of households in Lokoja, Kogi State. A total of 120 groundwater sources—70 hand-dug wells and 50 boreholes—were systematically sampled across major districts, selected based on population density and climate vulnerability. Thirty years of climatic data (1994–2024) from the Nigerian Meteorological Agency were analyzed to assess long-term variability, while groundwater levels were monitored seasonally. Water quality analyses covered physical, chemical, and bacteriological parameters, and socio-economic data were collected from 385 households through structured questionnaires and focus group discussions. Results showed mean annual rainfall of 1,280 mm and mean seasonal temperatures of 24.5°C (wet) and 32.1°C (dry). Dry periods caused a 35–40% decline in hand-dug well yields and a 12–15% reduction in borehole output. Forty-two percent of hand-dug wells exceeded turbidity limits in the wet season, nitrate averaged 28mg/L in vulnerable areas, and 38% of wells tested positive for total coliforms, while over 80% of boreholes remained within WHO standards. Socio-economic findings revealed that 73% of households adopted coping measures such as storage and alternative sourcing, with 58% incurring extra monthly costs averaging ₦3,500. Statistical analysis showed strong correlations (r = 0.62–0.78; p<0.05) between climatic variables and groundwater responses. The study concludes that climate variability significantly affects groundwater availability and safety in Lokoja, particularly for shallow hand-dug wells. It recommends improved borehole infrastructure, regular monitoring, and adoption of integrated water resource management. Application of these measures will enhance community resilience and support sustainable groundwater management in climate-vulnerable urban centers.