GLOF Modeling to Assess the Higher Himalayan Floods: A Case Study from Tsho Rolpa Glacial Lake, Nepal

Glacial Lake Outburst Floods (GLOFs) are becoming a major hazard in the Himalayas due to enhanced glacial retreat and lake expansion. The study of this paper is on Tsho Rolpa Glacial Lake in Nepal, one of the most potentially dangerous glacial lakes of the Himalayas. The study focused on simulating flood conditions through HEC-RAS 2D hydrodynamic modeling and remote sensing data from three years: 2015, 2020, and 2024. The spatio-temporal analysis verified the continuous growth of glacier size, width, and length because of the melting of the glacier. Symmetrical change patterns in cross-sectional profiles confirmed consistent broadening and deepening of the lake. hydrodynamic consequences—flood depth, velocity, and hydrograph—had increased magnitudes with time, and prominent downstream effects were observed. Flood susceptibility mapping supported the outcome of modeling to ascertain highly vulnerable zones in settlements such as Chankhu, Sikpasor Khani, and Jhyaku. GIS and remote sensing, combined with HEC-RAS, delineated a general picture of evolving GLOF hazards, enabling effective risk assessment and planning for disaster mitigation.