Change detection (1985-2020): Projections on land-use land cover, carbon storage, sequestration, and valuation in Southwestern Gambia

Abstract

ABSTRACT This study assesses land-use/land cover (LULC) change in the southwestern region of The Gambia, using remotely sensed satellite imagery. Using a geographic information system (GIS) software, I conducted a pixel-based supervised LULC classification applying the Random Forest Algorithm. I further used the classified LULC maps as part of the input parameters required to run the Integrated Valuation of Ecosystem Services and Tradeoffs (InVEST) Carbon Storage and Sequestration model. This study attributes the critical drivers of LULC change to deforestation, urbanization, industrial expansion, real estate development, climate change impacts, timber extraction, migration, and population density. Some of the factors are necessary for economic growth but not suitable for sustainable growth or development. The analysis reveals a forest cover loss of 22,408 ha (18% decrease) from 1985 to 2020 in the study area. The deforestation and other LULC changes between 2003 and 2020 have contributed to 21,824 metric tons of carbon emissions. The carbon loss is equivalent to an economic value ranging from US$521,526 to US$6,899,830. The study also presents three LULC projection (2020–2050) scenarios, namely, a business-as-usual (BAU), a new capital city (NCC) development, and a sustainability (SUST) pathway. Consideration of the study recommendations will minimize deforestation, increase carbon sequestration rate, support climate change mitigation, and provide adaptation co-benefits (e.g. urban flood mitigation).