Effects on ecosystem services value due to land use and land cover change (1990-2020) in the transboundary Karnali River Basin, Central Himalayas

Valuation of ecosystem services based on land use and land cover changes (LUCC) offers an incentive to people for sustainable use of the natural resources and can encourage people to adjust the land use sustainably. In this study, we used "Object-based Image Analysis (OBIA)," a remote sensing technique to extract the land use and land cover (LULC) of the transboundary Karnali River Basin (KRB, China and Nepal) from 1990 to 2020, and ecosystem services value (ESV) coefficients derived for the Tibetan Plateau has been used to assess the ESV. The basin has highest percentage of forest (33.44%), followed by bare area (30.29%), shrub/grassland (18.5%), agriculture (13.12%), snow/ice (4.36%), waterbody (0.3%), and built-up (0.03%) as of 2020. Over 30 years, 4.07 km(2) of the forest has been converted to agricultural land, 3.31 km(2) of agricultural land has been encroached by built-up area, whereas 2.82 km(2) of snow/ice area has melted into the waterbody. Furthermore, 80.85 km(2) of bare area has been converted to snow/ice, and 2138.83 km(2) of snow/ice has been changed to bare area. The ESV of KRB has increased by nearly 2.7 million USD from 1990 to 2020, primarily due to the increase in ESV from the conversion of 133.09 km(2) of snow/ice to shrub/grassland. The ESV of forest, waterbody, and snow/ice has decreased, whereas it has increased for other LULC classes in the basin. Spatial distribution of LUCC and assessment of ESV can be a tool to facilitate for better provisioning and regulating the resources for the future.