Page - 494 - in Book of Full Papers - Symposium Hydro Engineering

Fig. 1: 72 hours rain event: Extreme heavy rainfall event that took place on Aug 15th, 2015 in the area of Eastern Tibet 4. METHODOLOGY AND APPROACH The interaction among earth-surface erosion, slope failure, tectonic uplift and the climate is a key issue to understand the processes of mass movements in the study area. The local stress condition is an important factor that may relate to uplift, erosion, deposition, and groundwater fluctuation (Xu, 2014 a and b). The vertical motion and mechanism in Tibet is very complex: Several geodynamic processes control the complicated uplift pattern in the Tibetan Plateau, including the plate-tectonic movements, glacier isostatic adjustments and the mass loss related to the climate change conditions. The Tibetan Plateau located in central Asia is subject to the northward push from the Indian subcontinent and the collision with Eurasian plate, which results in East-West expulsion and uplift. The uplift rates of most part of the Tibetan Plateau range from 1 mm/yr to 2 mm/yr (Zhang & Jin, 2013). This general uplift also caused local fragmentation into blocks (kilometres or maximally, a few tens of kilometres) of local extent that have subsided and/or uplifted relative to one another. Alluvial deposition of the subsiding blocks contrasts with erosion and formation of gorges in the uplifted blocks. The question arises about the effects of tectonics in a relatively complex setting as drivers for the morphological development and the sedimentary architecture. The study region provides a framework of both regional tectonic uplift overprinted by tectonic movements of more local extent and changing over time. Climate change will have an influence on precipitations (duration, intensity, frequency, distribution). The following Fig.4 provides an overview of the precipitation distribution during the last decades. 494