Snow Avalanche Release Area Identification and Hazard Assessment Based on GIS and RAMMS Modeling: A Case Study of the Galongla Section of the Zhamo Highway, Xizang

As human activities and major infrastructure construction extend into high-altitude mountainous regions, the risk of snow avalanche disasters is increasingly severe. Generating avalanche hazard maps is a crucial foundational task. This study, focusing on the Galongla Section of the Zhamo Highway in Xizang, developed a framework for identifying potential avalanche release areas and conducting large-scale hazard assessments by integrating GIS and RAMMS numerical simulation technologies based on DEM data. This study defined a "general scenario" based on standard terrain parameter thresholds and an "extreme scenario" in order to assess the potential maximum hazard. The results indicate that under general and extreme scenarios, 539 and 526 potential release areas were identified, respectively. In the general scenario, the avalanche-affected area was 43.89 km², accounting for 54.58% of the total study area; under the extreme scenario, the affected area expanded to 53.24 km², representing 66.20%. Additionally, 16.7% and 25.8% of the highway section in the Galongla area were classified as high hazard level under the two scenarios, with maximum avalanche impact pressures exceeding 580 kPa. The avalanche hazard in the Galongla Section of the Zhamo Highway, Xizang, can be categorized into four hazard level levels: high, medium, low, and none. The high hazard zones are prioritized as target areas for mitigation engineering. This research establishes a portable and efficient avalanche hazard assessment framework by combining GIS-DEM analysis and RAMMS simulation, offering a practical solution for data-deficient high-mountain environments.