Author(s): S. O. Akande; O. O. Olajire; O. N. Adeyemi; O. O. Oni
Linked Author(s):
Keywords: Degradation; Hydropower; Management; Technology
Abstract: The nexus across land-water-energy are great potential for improved hydropower generation and efficiency in Nigeria. Very few studies have been conducted on environmental assessments of energy generation from Kainji Lake, though it is the largest hydropower plant in Nigeria. The research investigated the impacts of climate change and different land use types on hydrological ecosystem services and water availability in the Lake Kainji. The reduction in loss of water in the Lake, especially during the dry season (November- May) has been one of the major factors responsible for reduction in hydroelectric production from 86.97% capacity in 1974 to 20.90% in 2011. This study aims at accessing the socio-environmental and climatic factors affecting Kainji hydropower generation using the geospatial technology approach. To achieve this aim, Land Use/Land Cover assessment was carried out. Also, change detection, environmental impacts on water-reserve and usage in Kainji Lake were evaluated using multi-temporal Landsat imageries and meteorological datasets within the period of 1972-2018. Satellite images from MSS (1972), TM (1986), ETM+ (2001) and OLI (2018) sensors were used to obtain geospatial information such as the Normalized Difference Built-Up Index (NDBI), Normalized Difference Vegetative Index (NDVI), Modified Normalized Difference Water Index (MNDWI), Land Surface Temperature (LST) and Land Use/Land Cover (LULC) using ArcGIS 10.5 and ERDAS Imagine 2015 software. Rainfall, temperature, evaporation and sunshine duration are the most important climatic factors affecting the area of water area of the Lake. The Lake increased by an area of 90.9 km2 between 1972 and 1986, followed by shrinkage in 2001 (20.4 km2) and 2018 (95.2 km2). In total, there is an area loss of 24.7 km2 between 1972 and 2018. The Lake shrinkage is more prominent during the dry season (November-May) with estimated area reduction in the range of 900-950km2. The area lost by the lake is been replaced by farmlands and marshland, with the former increasing to 1151km2 in 2018. With respect to socio-environmental factors, settlements around Kainji Lake have increased in area covered trends of 2.5km2,73.58km2,437.77km2, and 627.52km2 in 1972,1986,2001 and 2018 respectively, giving rise to about 250% increase in built areas. Similar to the lake, forested areas have reduced from 2175.5km2 in 1972 to 1950.7 km2 in 2018 (ca. 10.3%), converting the areas to cultivated farmlands, croplands, rangelands and (bare lands as observed in the dry season). Mitigating the impacts therefore advocates for greater cooperation, and the strengthening of the decision makers to ensure sustainable regulation and resources management of the drying Lake.
Year: 2022