Emerging heat stress and local prospects in Punakha, Bhutan: Opportunities and challenges of satellite-based observation

Punakha, nestled in the foothills of the Greater Himalayas in Bhutan, is renowned for its enduring traditional farming practices and profound cultural legacy. However, global warming and the consequent rise in temperatures have emerged as a significant local concern. The study aims to ascertain the patterns of land surface temperature (LST) over a 30-year period and establish a connection between these trends and community prospects. LST was assessed using Remote Sensing (RS) techniques on the Google Earth Engine (GEE) platform and subsequently mapped within a Geographic Information System (GIS). A total of 55 Landsat images were available and 17 were analyzed after cloud screening. Community survey results were corroborated with satellite-observed data on the effects of heat stress on agriculture and socioeconomic well-being. The LST trend shows significant warming in Punakha. The pre-monsoon single-day maximum LST and the average maximum LST rose by ∼2.8°C and ∼3.55°C per decade, respectively. Similarly, the post-monsoon average maximum LST rose by ∼2.51°C per decade. The community surveys revealed a significant climate vulnerability, in which 92.8% reported declining water resources due to rising temperature, and 52.7% of respondents reported decline in agriculture productivity. Subsequently, 43.6% of respondents reported direct livelihood impacts with 98.2% of respondents agreeing that rising temperatures is a serious concern, while no significant negative health effects were observed. The study emphasizes the necessity of local climate risk assessment for promoting climate-smart agriculture in vulnerable Himalayan valleys and recommend for enhanced climate action (SDG 13) toward a robust National Adaptation Plan (NAP).