Effects of land use and land cover changes on ecosystem services and functions in the Kulpawn River Basin of Ghana

Abstract

The Kulpawn River Basin (KRB) plays a critical role in supporting rural livelihoods through agriculture, water supply, and biodiversity conservation. However, between 1995 and 2023, significant land use and land cover (LULC) changes have been observed, affecting ecosystem services (ESs). This study evaluated the ecosystem service values (ESVs) associated with LULC changes. The random forest algorithm was applied to extract LULC information from Landsat images for 1995, 2005, 2015, and 2023. The benefit transfer method was employed to estimate the ESVs over the study period. Questionnaires were also used to assess the views of respondents on the drivers of the ES changes in the basin. The results showed that agricultural lands expanded by 14.14%, built-up areas by 15.17%, and light savannah forest by 8.73%, while dense savannah forest and water bodies declined by 25.71% and 20.00%, respectively. The total estimated ESV was 410.09×10 8 , 362.92×10 8 , 335.30×10 8 , and 319.28×10 8 USD/(hm 2 •a) in 1995, 2005, 2015, and 2023, respectively, indicating that the total ESV declined from 410.09×10 8 USD/(hm 2 •a) in 1995 to 319.28×10 8 USD/(hm 2 •a) in 2023. The study concludes that the reduction in ESVs is due to the LULC changes resulting from agricultural activities, expansion of built-up areas, population sprawl, and artisanal mining activities. Hence, there is an urgent need to develop programs and strategies to mitigate and curtail the degradation of LULC and ESVs in the basin. These findings reveal a growing ecological vulnerability, threatening water security and rural livelihoods. The study offers valuable insights to guide sustainable land use planning and ecosystem conservation strategies.