Annualmeeting:2017 CSDMS meeting-064
Landscape reorganization under changing external forcing: implications to climate-driven knickpoints
[[Image:|300px|right|link=File:]]A series of controlled laboratory experiments were conducted to study the effect of changing precipitation patterns on landscape evolution at the short and long-time scales. High resolution digital elevation (DEM) both in space and time were measured for a range of rainfall patterns and uplift rates. Results from our study show distinct signatures of extreme climatic fluctuations on the statistical and geometrical structure of landscape features. These signatures are evident in widening and deepening of channels and valleys, change in drainage patterns within a basin and change in the probabilistic structure of erosional events, such as, landslides and debris flows. Our results suggest a change in scale-dependent behavior of erosion rates at the transient state resulting in a regime shift in the transport processes in channels from supply-limited to sediment-flux dependent. This regime shift causes variation in sediment supply, and thus in water to sediment flux ratio (Qs/Qw), in channels of different sub-drainage basins which is further manifested in the longitudinal river profiles as the abrupt changes in their gradients (knickpoints), advecting upstream on the river network as the time proceeds.