Determination of the Effect of Gully Erosion on Land Use in Nyuwar District, Balanga Local Government Area of Gombe State, Nigeria

Nyuwar District is typical of heavy black soil developed from basaltic rocks highly susceptible to gully erosion due to its hilly terrain. This research aimed to determine the effect of gully erosion on land use in Nyuwar district. Data were collected from field observation, in-depth interviews, and satellite images. The data were analyzed using descriptive statistics, and GIS methods such as supervised image classification techniques and overlay. Satellite imageries for 2007 and 2020 were used to map the extent and spatial distribution of gullies and other land use and land cover such as builtup areas, farmlands, and vegetation covers. Over the last 13 years, the extent of gully erosion in the study area increased markedly, mostly on cultivated land, while gully density rose from 45.56 ha (0.4556 km2 ), representing 2.28% in 2007, to 56.67 ha, representing 2.83% in 2020. Built-up areas increased over the study period, but vegetation cover decreased markedly from 535.39 ha (26.75%) in 2007 to 344.14 ha (17.19%) in 2020. It was concluded that from 2007 to 2020, 14.97 ha of farmlands have become gullied due to erosion. If 1 ha of land produces 15 bags of maize, it follows that 233.91 bags (2.334 tonnes) of maize were lost due to gullies. It is recommended that there should be a routine inspection of the farmlands to see if there are possible chances of future occurrences of gullies to decide possible ways of controlling them. Planting of fast-growing species of plants along the banks of the gullies should be embarked upon to check further loss of farmland to gullies.