Evaluating the impact of land use land cover changes on the values of ecosystem services in the Chacha Watershed, Ethiopia's central highland

Abstract

Land use/land cover (LULC) changes are the foremost drivers that enormously modified ecosystem services in Ethiopia. Evaluating LULC changes impacts on ecosystem services values (ESV) is vital to show the susceptibility of ecosystem services and also have an indispensable role in land resource management. This study was conducted to (1) determine the tempo-spatial LULC changes; and (2) estimate the ESV in response to LULC changes in the Chacha Watershed, central highlands of Ethiopia. A supervised image classification technique using the maximum likelihood classifier was employed to analyze the trends of LULC changes over the past 24 years, i.e., 1997–2021 periods. The ESV of the identified LULC types was estimated using ecosystem service value coefficients. The findings revealed that the largest area of the Chacha Watershed was covered by cultivated land, followed by open grassland and forest land. The cultivated land decreased by 16.30% whose rate is about 5.09 km2 yr−1. In contrast, the forest land increased by 49.52% with an annual increasing rate of 1.17 km2. Moreover, the built-up area showed a 905.06% increase in size during the analysis periods. The estimated overall ESV of each analysis period ranged from US$ 32.7 million in 1997 to US$ 35.56 million in 2006. The largest ESV was recorded for the cultivated land, followed by the open grassland and the forest land. Annually, there is a net positive gain of US$ 80 thousand of change of ESV in the study watershed. This indicates that the small positive change in the size of the forest land has significantly increased the ESV. The promising positive change of the ESV for the forest land, the open grassland, and the riverbeds is an indication that the total ESV can be maximized by increasing the land coverage for these three LULC types in the study watershed. The resulting scientific insights and knowledge are essential to highlight existing concerns on the tempo-spatial changes of LULC and their associated impacts on the ESV. This may in turn assist policy- and decision-makers and land-use planners to make an appropriate resource allocation decision in order to achieve sustainable management of ecosystems and their key attributes.