TIBETAN PLATEAU SNOW COVER VARYING WITH CLIMATE CHANGE: A REGIONAL CLIMATE PERSPECTIVE

Abstract. The Tibetan Plateau (TP) is experiencing dramatic climate changes, which increases the geographical hazard risks affecting human lives and properties. As TP holding the largest cryosphere extent outside the polar region, frequent and serious snow disasters become the crucial topic in the TP disaster reduction and management. The primary task to cope with TP snow disasters is to understand the formation and evolution of snow cover as the basis to assess and predict geographical hazards. Considering time variability and spatial heterogeneity, the geographical detector analysis has been adopted to investigate the coupling relationships between snow cover and climate change in the different periods (1989-2018) and different geographical regions (Qaidam areas, Qiangtang areas and Hengduan Mountains). The following results are noted: (i) Regionalization provides a better climate explanation for snow cover compared with the non-regionalized whole plateau model, which verifies again that the snow cover distribution and its driving mechanism both have strong spatial heterogeneity. (ii) Temperature has a dominant influence on the snow cover in all three regions, showing that net surface energy flux balance is the major limitation to the snow cover so that temperature becomes the key factor of snow-related risk management. (iii) The impact of precipitation on snow cover is only significant in the Qaidam areas according to the interaction detector approach, where the combination of temperature and precipitation can explain more than 65% of the snow cover distribution. Thus the Qaidam areas requires risk monitoring related to both hydrological and thermal aspects.