Authors
Yuval Shmilovitz (CIRES)
Abstract
Over the recent geological past, alternations in the sediment budgets of low-order dryland catchments have left behind pronounced topographic imprints and are observed worldwide. The modern consequences of similar shifts extend from damage to ecosystems and crop yields to worldwide geopolitics. Quantifying erosion trends and understanding potential drivers for changes in the sediment budget is, however, a long-lasting challenge; ephemeral catchments are commonly situated in hydrological and vegetation boundary zones, greatly impacted by fine-scale and episodic erosion-triggered climatic events that are hard to observe and computationally complex over landscape evolution time scales. This poster presents a set of catchment-scale landscape evolution numerical experiments designed according to field observations and projected climate records for the end of the 21st century derived from a convection-permitting climate model. The results demonstrate how changes in minute-scale rainfall bursts, as measured under modern global warming, could significantly enhance erosion rates and impact multi-century landscape evolution, even without a change in the general wetness level. Further, the presented modeling approach translates the future climate projection over the High Plains of Colorado into changes in vegetation cover along with an increase in sediment yield, which is contrary to the predicted general reduction in precipitation over the region. Modeling results, in conjunction with hints from a study area, reveal key relations between catchment morphology, soil/lithological properties, and vegetation cover that contribute to the understanding of landscape evolution under climatic changes.