The Arun River Valley is one of Nepal's deepest valleys, located in Koshi District in the north-eastern part of the country. Tibet is said to be the source of the Arun Valley, which flows down to Nepal's Himalaya and then into India's Ganges. This river is thought to have a lot of potential for hydropower production because of its high flow and steepness. Our crew was particularly interested in the Upper Arun Hydropower Project, which is now being planned and built. Experts in macro aquatic invertebrates, fisheries, river dynamics, and topographic survey make up our team.


Autel Evo 2 drone was used to conduct the UAV survey of Arun River. A field plan was addressed in the drone and the autonomous survey of the field was conducted through it. Drone flights lasted at the average of 10 minutes. Control points were established using EMILD Reach RS+, a DGPS instrument. Cross sectional data from the way of flow of river were acquired using DGPS and TS survey. RTK method was performed to capture data along the cross-sectional line using DGPS. Total station was used in a reflector mode at those points that were out of reach to visit manually. The data was taken at 5 meters interval along the line of flow and covered 15 meters in either direction from the deepest point of the river along the cross-sectional line.