Risk Assessment and Predictive Modelling of Shishper Glacier Surge and Glof

Abstract

Over the last decades, experts have observed irregular behavior and lack of stability of Karakoram Glaciers. These behaviors include glacier surges and formation of glacier lakes. Global warming has influenced this trend, as people have started living near the mountains. People have raised construction industry, hydropower plants, tourism resorts and leisure spots etc. Risks associated with the GLOFs pose a serious threat to communities in Karakoram Mountains of Pakistan. Glacier lake is formed as a result of Shishper glacier surge that has potential to submerge the infrastructures in downstream i.e. Karokaram Highway, Bridge, houses, FWO camp and two powerhouses if outburst occurs. The low-lying areas alongside the Hunza River are also vulnerable to flood. This study was designed to map the spatio-temporal movement of Shishper glacier and its glacial lake and to predict and assess the risk of glacier surge and lake burst phenomenon. To fulfil the objectives following softwares and models were used i.e., ArcGIS (Preprocessing and creation of data for glacier surge and GLOF simulation), HECRAS (for GLOF simulation), Global Mapper (creation of watershed area in AOI) and Rapid Mass Movement and Simulation RAMMS (for glacier surge). Through predictive modelling, the volume of the glacial lake is estimated to be 200 million cubic feet and draining at the rate of 15 CUSEC (flow will increase gradually). With glacial mass sitting along a stretch of more than 565 m in its flow path, possibility of the lake outburst is not likely. However, the debris flow of glacier was predicted through predictive modelling. The study commends the glaciers has an abnormal behavior, it is essential to track the Glacier and Glacier lake frequently and reduce the terrible effects of possible GLOF threat. Sabo dams, protection walls along Hassanabad village and FWO camp, debris flow breaker are recommended