Evaluation of unsustainable land use/land cover change on ecosystem services in coastal area of Lagos state, Nigeria

Increasing human-induced developmental activities around the Eti-Osa coastal area of Lagos state, Nigeria has continued to trigger social and environmental challenges that have not been given desired attention. The study therefore attempted to utilize Landsat TM 1984, ETM+ 2000, and OLI 2013 to estimate the changes in the land use/land cover categories using GIS techniques, economic valuation method, and monetary valuation model to estimate the ecosystem service loss. The result showed that the built-up increased by 973.63Ha between 1984 and 2013 while 6717.65Ha, 1314Ha, and 1740.49Ha of mangrove, wetland, and water bodies respectively were lost to land reclamation. In monetary term, the study established ecosystem service loss of US$101.59 million per annum for the study period. It further estimated ecosystem service loss caused by damage to mangrove and food supply services at US$113.77 million and US$21.83 million per annum respectively. It was observed that land reclamation activity for urban and industrial uses has significant effect on the ecosystem service loss. By implication, socio-economics of the inhabitants were impacted by drastic decline in the income accrued from fishing activities and collapsing infrastructure arising from unsustainable land use activities through land reclamation and emerging flooding. The study advocates adoption of rigorous ecosystem resource accounting in subsequent environmental impact analyses on all future land-reclamation projects.