Resources Himalaya Foundation and Environmental Graduates in Himalaya successfully organized 116th series of Pralad Yonzon Conservation Forum (PYCF) with Dr. Reeta Singh, Assistant Professor at Patan Multiple Campus, Tribhuvan University. She gave a talk on the topic “Climate change and river health of the Marshyangdi Watershed, Nepal: An assessment using integrated approach”.
The talk started with Dr. Singh giving a brief introduction about river health, anthropogenic factors and climate change affecting river health by changing the hydrology of river. Dr. Singh elaborated that there are various methods of assessing the river health; traditionally physiochemical analysis was being done for assessing the water quality but it only provided information at a specific spatial unit rather than historical information on it. So, the concept of using biological aspect came into existence along with the physiochemical aspect which uses the variety of ecosystem components like biological indicators and physical indicators and the catchment characteristics. The main objective of the research was to assess the health status of Marshyangdi River under climate change. This snow-fed watershed already has 3 large hydropower projects running in the river. The study used various metrics and indicators under hydrological, water quality, biological, and physical components.She further mentioned highlighted that the climaticdata from DHM was quality checked and downscaled in order to project the future climatic scenarios using Regional Climatic Models. The biophysical data like landuse landcover, digital elevation model and climatic data were fed in SWAT model and then the model was calibrated and validated. The discharge was measured by using Area Ratio method, whereas the current river health was determined through habitat condition by the help of RBP protocol.For future river health,the future hydrological conditions were estimated by flow health tools and after that discharge was measured. Finally, by keeping the habitat condition constant, Maxent modeling was used for determining future biological health. The result of the study shows that overall river health was found to be of moderate category as observed in 71% of the site. However, poor conditions were found in the sites having tributaries and the upstream region also had poor quality. On the other hand, water quality was predicted to be in same status in both near and mid-future scenarios with varying degree of percentage under both RCPs. She concluded the talk by discussing about the uncertainty in the results due to the constant nature of pollutant emission and anthropogenic activities including other compounding factors like urbanization, landuse, population growth, which are not considered in the study. The presentation was followed by an interaction session between the guest speaker and the participants and ended with a vote of thanks from EGH coordinator.