Snow avalanche detection using Sentinel-1 in Langtang, Nepal

Abstract

This report summarizes NORCE’s contribution to the snowAMP2-project where NVE and ICIMOD are working on cryospheric processes and hazards in the Langtang catchment in Nepal. We contribute with radar satellite-borne snow avalanche detections using Sentinel-1 data. The goal is to establish a multi-year inventory of snow avalanche activity in the Langtang catchment. In this report, we show the results of Sentinel-1 borne snow avalanche detection and discuss the strengths and weaknesses of the used method. We further explain the processing system and work logic applied and discuss other possible workflows for Sentinel-1 data geocoding and change detection. We then show a step-by-step process that increases our confidence in the automatic detections being indeed snow avalanches instead of false alarms. We end with some recommendations on how applicable our methods are to the Langtang catchment and conclude with some basic statements about the snow avalanche regime in the area.