Abstract

Human well-being was obsessed with the natural scheme that provides various functions vital to support management at various levels. Land use/ land cover (LULC) dynamics over 45 years within four intervals (1972, 1986, 2008, and 2017) to evaluate its influence on ecosystem services. Geographic information system (GIS) and global value of coefficients’ database together with LULC dynamics were used to determine ecosystem service values (ESV). The results showed that cultivated land and settlement land expanded by 67.38 and 532% respectively whereas forest land, shrub land and grassland declined by 66.35 and 18.36% respectively over the analysis period. A decline of total ESVs from US$ 35.23 million in 1972, to 33.61, 27.91 and 25.87 million in 1986, 2008 and 2017, respectively. Approximately US dollar of 9.37 million ESVs were lost owed to LULC changes from 1972 to 2017 in the sub-watershed. In terms of ES functions, erosion control, nutrient cycling, climate regulation and raw material provisions were the key bringers to loss of ESV. Global ESV data sets together with LULC change information helps to make a possible judgment about past environmental changes and reliable results achieved to make sound decisions. The decline of ESV was an indication of environmental degradation in the sub-watershed and needs future appropriate intervention policies in land conservation.

Key words: Land use/Land cover, Bilate Alaba subwatershed, ESV, geographic information system (GIS), remote sensing, landsat image.