Impact of land cover, soil type and topography on groundwater resources in Ebonyi State, Southeastern, Nigeria

Understanding the interplay between land use, topography, and soil properties is crucial for effective groundwater management. Ebonyi State, Nigeria, exhibits diverse land cover types, slope variations, and soil characteristics, all influencing groundwater dynamics. This study aims to analyze these factors to inform sustainable groundwater management practices. The primary aim is to assess the spatial distribution of land use/land cover (LULC), slope, and soil types in Ebonyi State and their implications for groundwater recharge, availability, and quality. The study employs geospatial analysis techniques to map and quantify LULC, slope, and soil types across Ebonyi State. Data were collected from satellite imagery, topographic maps, and soil surveys. The analysis involved classifying land cover types, calculating slope gradients, and determining soil erodibility (K-factor). The LULC analysis revealed that rangeland is the dominant land cover type, covering 4223.89 km², indicating extensive grazing activities. Forested areas, covering 812.81 km², play a significant role in groundwater recharge through enhanced infiltration. Agricultural lands (754.11 km²) suggest considerable groundwater extraction for irrigation. Urban areas (374.07 km²) pose challenges for groundwater recharge due to increased surface runoff. Water bodies and flooded vegetation, though covering smaller areas, contribute positively to groundwater recharge. The slope analysis showed that gentle slopes (0 - 1.49 degrees) dominate, favoring groundwater recharge. Steeper slopes exhibit higher runoff rates, reducing recharge potential. The soil analysis identified four main soil types: Ferric Acrisols, Gleysols, Dystric Gleysols, and Dystric Nitosols. Dystric Nitosols, covering the largest area, are well-drained and suitable for groundwater recharge, while Gleysols and Dystric Gleysols present drainage challenges. The extensive rangeland and forested areas enhance groundwater recharge, while urbanization reduces it. Gentle slopes support recharge, but steeper slopes require erosion control measures. Dystric Nitosols are favorable for groundwater recharge, but Ferric Acrisols and Gleysols need targeted management to mitigate erosion and improve drainage. Effective groundwater management in Ebonyi State requires a nuanced understanding of LULC, slope, and soil types. Rangeland and forested areas should be preserved for their recharge benefits, while urban expansion needs careful planning. Soil conservation and sustainable agricultural practices are essential to enhance groundwater recharge and maintain water quality. To ensure sustainable groundwater management, implement erosion control measures in Ferric Acrisols, effective drainage systems for Gleysols, and promote sustainable agricultural practices in Dystric Nitosols to enhance soil structure and groundwater recharge.