SGER: How Do Hillslope-to Catchment-Scale Flowpaths Develop in Response to an Extreme Drought Followed by Record Precipitation

本研究将利用北方新墨西哥州降水量的变化达到前所未有的水平，以提高对集水区内水的路径和停留时间的机械理解。北方新墨西哥州在过去的六年里一直经历着严重的干旱。2006年水年的开始继续这个干燥的时期，在有记录的历史上最低的积雪，导致第一，第二，和一些第三级流在我们的研究现场运行干2006年夏天。然而，2006年季风季节的特点是112年来最高的降水总量，这使2006年秋季以前干涸的溪流重新恢复了流动。我们建议利用这一不寻常的事件，结合正在进行的研究，在我们的研究地点的生态水文学，发展的数据和模型表示的分布式水文响应降水的变化。我们的研究设计包括八个嵌套的一阶子集水区位于径向周围的中央山脉。这八个子集水区排入三个以前的仪器流，随后加入，形成一个单一的出口，从我们的研究地点。虽然植被和母质是相似的整个集水区，在水和能源方面的变化导致非常不同的模式在土壤深度和发展。最初的流地球化学监测，作为以前的研究工作的一部分，表明非常不同的水的停留时间有关的方面，这些模式。我们的项目将直接解决现场数据的需求，以实际测试集水区流径发展模型，而不是简单地匹配模型。我们希望这项活动能够在理解景观中水的时空变化的控制方面取得重大进展。此外，物理为基础的，在小流域尺度的山坡水运动的空间现实的表示将允许的生产和出口的生态地球化学循环元素的降水变化的响应如何进行定量评估。

This study will take advantage of an unprecedented level of variability in precipitation in northern New Mexico to improve the mechanistic understanding of the routing and residence time of water within catchments. Northern New Mexico has been experiencing a severe drought for the last six years. The beginning of the 2006 water year continued this dry period with the lowest snowpack in recorded history resulting in first, second, and some third order streams at our study site running dry by summer 2006. The 2006 monsoon season however was characterized by the highest precipitation totals in 112 years which has reestablished flow in the formerly dry streams through the fall of 2006. We propose to take advantage of this unusual event, combined with ongoing studies in the ecohydrology of our study sites, to develop both the data and the model representations of the distributed hydrological response to variability in precipitation. Our study design includes eight nested first order sub-catchments located radially around a central mountain. These eight sub-catchments drain into three previously-instrumented streams, which subsequently join to form a single outlet from our study site. Although vegetation and parent material are similar throughout the catchments, variability in water and energy related to aspect result in very different patterns in soil depth and development. Initial stream geochemical monitoring, conducted as part of previous research efforts, suggests very different residence times of water related to these patterns in aspect. Our project will directly address the need for field data to actually test models of catchment flow path development, rather than simply match models. We expect this activity to make significant advances in understanding the controls on the spatial and temporal variation of water in the landscape. Furthermore, the physically-based, spatially-realistic representation of water movement at the hillslope to small catchment scale will allow a quantitative evaluation of how the production and export of biogeochemical cycling elements respond to variability in precipitation.