The impacts of land-use and land-cover change on wetland ecosystem service values in peri-urban and urban area of Bahir Dar City, Upper Blue Nile Basin, Northwestern Ethiopia

Abstract

Background: Even though wetlands are essential in enhancing water quality and providing recreation and entertainment opportunities in urban areas, their values are overlooked by the decision-makers. Underestimation of the economic value of wetland ecosystem services contributes to their continuing deterioration and inevitable loss. Investigating the changes in ecosystem service values (ESV) can provide crucial information for decision-making. This study, therefore, analyzes the temporal and spatial land-use/land-cover (LULC) change patterns over 35 years (1984–2019) intending to evaluate its impact on wetland ecosystem service values in Bahir Dar City, Ethiopia. Estimation and change analyses of ESVs were conducted by employing ArcGIS using LULC inputs of the year 1984, 1994, 2004, 2014, and 2019 with their corresponding global value coefficients that were developed earlier and our own modified value coefficients for the studied landscape. Results: The results showed that wetlands and water bodies of the city and its peripheries had decreased by 75.71% (−1618 ha) within 35 years, while built-up area increased by 216.24% (+2599 ha). Cultivated land had increased slightly from 1984 to 1994 and then gradually declined since 1994. Changes in LULC had resulted in a decline of the total ESV. The total ESV had decreased from USD 29.73 × 106 to USD 20.84 × 106 in 35 years. This indicates the loss of nearly USD 8.9 × 106 ESV from 1984 to 2019. A sensitivity analysis suggested the robustness of ESV estimation in the study area. All individual ecosystem services experienced a negative change. However, a greater reduction in ESV was observed for services such as water regulation, waste treatment, and habitats for maintaining biodiversity. The expansion of built-up area of Bahir Dar City was the major factor that contributed to the loss of ESV provided by wetlands. Conclusions: The loss of ESV resulting in LULC changes has a negative implication on local climate, waste management, and the livelihoods of the poor community. Thus, interventions should be made for the restoration and sustainable management of wetlands in the urban and peri-urban areas of Bahir Dar City.