Wetlands' Response to Climatic Variability: Empirical Evidence from the Kumadugu-Yobe River Basin of West Africa

The wetlands of the Kumadugu-Yobe River Basin are the economic mainstay of the lower and mid-stream basin population, providing a wide range of ecosystem services and functions. However, series of impediments have been altering the hydrology of the sub-basin wetlands since the early 1970s. In order to understand the extent of the impact of climate variability on the basin wetlands, this study mapped the temporal variability in wetland size from 1982–2018 and examined the wetland's response to rainfall and temperature variability. The study used advanced very high resolution spectroradiometer (AVHRS) and moderate-resolution imaging spectroradiometer (MODIS) NDVI data sets of 1982–2018 rainfall and temperature data from upstream and downstream stations. Geo-spatial technology and statistical tools were used in analysing the collected data. The findings reveal a large-scale annual increasing trend of 337km 2 in wetland size between 1982 and 2018, as against the orthodox view of continuous degradation. The result of the analysis revealed that the wetland’s response to a 1% increase in downstream annual rainfall, upstream annual rainfall, Jos August rainfall and downstream temperature was by expanding by 5.2 km 2 , 7.5 km 2 , 33 km 2 and shrinking by 1,456 km 2 , respectively. The study concluded that the basin wetlands respond significantly to any slide fluctuations in rainfall and temperature variables. Based on the findings, the research recommended proper water management strategies within the basin, especially in the Kano region. Water diversion into Tiga and Challawa dams from neighbouring basins is thus a key to the contentious existence of the basin wetlands.