Author(s): Christoph Haemmig; Matthias Huss; Josef Hess; Zhigang Ao
Linked Author(s):
Keywords: Glacial Lake Outburst Flood (GLOF); Early Warning System; Remote sensing; Risk management; Climate Change monitoring
Abstract: The catchment area of YarkantRiver is located in the KarakoramMountains in the southwest of Xinjiang Uygur Autonomous Region, China. In the last decades, several glacial lake outburst floods (GLOF) damaged infrastructure and claimed human lives along YarkantRiver in the TarimBasin. The spontaneous floods are a threat to over 1 Mio inhabitants in the floodplains of Yarkant River and are causing an annual monetary loss of approx. 10 Mio Euro. There are 33 recorded flood disasters between 1949 and 1999. The floods are provoked by melt-water, by rainstorms and – most violent and disastrous – by glacial lake outbursts, effectuating peak discharges of more than 6’000 m3/s. The largest and most frequent glacial lake outbursts occur in the area of KeleqinRiver in the upper ShaksgamValley of the KarakoramMountains. Keleqin is one of several tributaries of YarkantRiver. The GLOFs originate from a remote ice-dammed glacier lake at 4’750 m a. s. l., approx. 560 km upstream of the floodplains. There, Kyagar Glacier tongueentirely blocks the riverbed. Based on a Memorandum of Understanding between the Ministry of Water Resources of China (MWRC) and the Swiss Federal Department of the Environment, Transport, Energy and Communications (DETEC), it was decided to initiate a Sino-Swiss project with the goal to implement an early warning system, allowing authorities and population to take the necessary measures in order to avoid victims, to raise the safety of settlements and livestock and to minimize damages to infrastructure and agricultural land. A further goal is to assess the long-term development of the flood hazard situation in the catchment area of YarkantRiver by analyzing past and real-time information/data on the glacier lake situation. In addition, scenario based forecasts of the future glacial lake developments are elaborated, considering on-going climate change. As a first step, a GLOF Early Warning System (EWS) was implemented combining satellite remote sensing and two automatic terrestrial observation and warning stations. The first automatic gauge and warning station is situated approx. 200 km downstream of KyagarGlacierLake and is operational since autumn 2011. Both water level fluctuations and EWS functionality are continuously monitored. The second automatic observation station is located directly at the glacier lake and is fully operational since autumn 2012. Based on camera images, the GLOF hazard potential can be identified. Both terrestrial stations are equipped with weather sensors for the monitoring of the local climate. Because the volume of KyagarGlacierLake is directly linked to its blocking icedam, an assessment of glacier dynamics and ice meltis crucial. Such calculations and climate change monitoring are needed to define future hazard scenarios and to plan protection measures. Flood modelling, the elaboration of a hazard indication map and an emergency risk management plan are other key issues of the on-going project.
Year: 2013