Sustainable development goals, governance and assessment of the impact of urban growth on vegetation cover in Benin City, Nigeria, using land-use–land-cover change trajectories

Abstract

Land-use/cover (LULC) and governance are key elements in the attainment of the Sustainable Development Goals. This study focused primarily on LULC changes in Benin City, Nigeria, from 1992 to 2022; to examine how urban growth affected vegetation cover across four time points: 1992, 2002, 2015 and 2022. Variable LULC classifications considered included: built-up areas, open spaces/bare lands, vegetations, waterbodies and wetlands. In three decades (1992–2022), increases in the built-up, open space/bare land and wetland LULC were observed and attributed to population increases and higher infrastructural demands whereas evident reductions in the sizes of vegetation and waterbody categories were ascribed to anthropogenic activities and climate events. The average annual rates of change in the built-up and vegetation LULC increased (7.28%) and decreased (−3.02%), respectively, between 1992 and 2022; with the built-up area experiencing a 218% increase from 6493 to 20,672 (km2) whereas vegetation decreased by 90% from 23,445 to 2239 (km2). The corollary is that urban growth, exemplified by the built-up LULC, was progressive while vegetation cover was depleted, in the 30-year period. Changes in five other periods were also interrogated. Government and stakeholders-promoted afforestation and agroforestry programs are recommended as plausible solutions to check vegetation-cover depletion. Other solutions proffered include the support of relevant farmers’ trainings in climate-smart and hydroponic agriculture, and the application of sustainable farming techniques. Policymakers and estate developers/managers should encourage sustainable land governance and cities with resilience and coping capacities; to tackle the problem of climate change, with high emphasis on green area developments.