Spatio-temporal landscape changes and the impacts of climate change in mountainous Bhutan: A case of Punatsang Chhu Basin

Abstract

Agro-ecological landscape changes along the Punatsang Chhu (River) Basin of Bhutan was assessed using Geographic Information System (GIS) and Remote Sensing techniques. The study used satellite data (Landsat imageries) of three periods (1996, 2010 and 2017). The results showed a 51% reduction in the snow and glacial area over the last 20 years. Further, the area under rock outcrops and bare land almost doubled from 8 % in 1996 to 15 % in 2017 during the same period. These changes could be directly related to the impacts of climate change since the study site showed increases in both maximum and minimum temperatures by about 1 °C and 0.5 °C, respectively based on 1997 to 2017 data. The seasonal average rainfall during the same period also showed a decreasing trend from a high of about 800 mm to 400 mm, which might have affected snow and glacier cover in the higher mountains. Thus, this research further confirms the existing knowledge that climate change impacts are more severely felt in the high altitudes and mountainous locations, such as the Himalayas. The study highlights land cover changes due to climate change and anthropogenic factors which could be used for suitable policy interventions and management of natural resources.