Collaborative Research: RUI: Investigating the role of hillslope processes in modulating topologic change of upland drainage basins.

流域边界或排水分水岭控制着景观中水和沉积物的流量，并驱动着水生生物的进化和物种形成。在地质时期，排水沟随着气候和地质构造的变化而移动。这项工作探讨了如何运动的分歧之间的缓坡，土壤覆盖的景观和陡峭，山区，岩石地区。具体来说，研究人员将比较土壤沿沿着蠕动的景观和主要通过山体滑坡运输的景观。他们将使用数字制图技术，土壤和沉积物特性的实地测量，以及景观演变的理论模型来调查影响分水岭运动的成分。与以前的研究不同，它侧重于河道，这项工作强调发生在山坡上的过程。 地形分析，实地测量的粒度，和侵蚀速率从宇宙成因核素说明的作用，非河流的过程中调制的地形变化的流域。为了捕获从土壤覆盖到岩石景观中的山坡和崩积输送机制，这项工作利用了一系列区域侵蚀速率（奥扎克高原，俄勒冈州海岸山脉，圣加布里埃尔山脉）的实地测量。除了测试现有的地形指标分水岭不稳定性，这项工作寻求定量方法的改进，以更好地将陡峭的景观纳入描述和预测分水岭不稳定性的理论框架。该奖项反映了NSF的法定使命，并已被认为是值得通过使用基金会的智力价值和更广泛的影响审查标准进行评估的支持。

Watershed boundaries, or drainage divides, control the flux of water and sediment in a landscape and drive evolution and speciation of aquatic organisms. Over geologic time, drainage divides move in response to changes in climate and tectonics. This work explores how the motion of divides differs between gently sloping, soil-mantled landscapes and steep, mountainous, rocky areas. Specifically, the researchers will compare landscapes where soil creeps along hillslopes with those where material is primarily transported through landslides. They will use digital mapping techniques, field measurements of soil and sediment characteristics, and theoretical models of landscape evolution to investigate the ingredients that affect divide motion. Unlike previous research, which focuses on river channels, this work emphasizes processes that occur on hillslopes. Topographic analysis, field measurements of grain size, and erosion rates from cosmogenic nuclides illustrate the role of non-fluvial processes in modulating topographic change of drainage basins. To capture hillslope and colluvial transport regimes in landscapes ranging from soil-mantled to rocky, this work leverages measurements from field sites across a range of regional erosion rates (Ozark Plateau, Oregon Coast Range, San Gabriel Mountains). In addition to testing existing topographic metrics for divide instability, this work seeks quantitative methodological improvements to better incorporate steep landscapes into theoretical frameworks that describe and predict divide instability.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.