Assessment of Changes in the Value of Ecosystem Services in the Koshi River Basin,Central High Himalayas Based on Land Cover Changes and the CA-Markov Model

Climate warming and economic developments have created pressures on the ecological systems that human populations rely on, and this process has contributed to the degradation of ecosystems and the loss of ecosystem services. In this study, Landsat satellite data were chosen as the data source and the Koshi River Basin (KB) in the central high Himalayas as the study area. Changes in land cover and changes in the value of ecosystem services between 1990 and 2010 were analyzed and the land cover pattern of the KB in 2030 and 2050 was modeled using the CA-Markov model. Changes in land cover and in the value of ecosystem services in the KB for the period 2010-2050 were then analyzed. The value of ecosystem services in the KB was found to decrease by 2.05×10⁸ USD y^-1 between 1990 and 2010. Among these results, the services value of forest, snow/glacier and barren area decreased, while that of cropland increased. From 1990 to 2050, forest showed the largest reduction in ecosystem services value, as much as 11.87×10⁸ USD y^-1, while cropland showed the greatest increase, by 3.05×10⁸ USD y^-1. Deforestation and reclamation in Nepal contributed to a reduction in the value of ecosystem services in the KB. Barren areas that were transformed into water bodies brought about an increase in ecosystem services value in the lower reaches of the Koshi River. In general, this process is likely to be related to increasing human activity in the KB.