Collaborative Research: Understanding the Hydrologic Implications of Landscape Structure and Climate -- Towards a Unifying Framework of Watershed Similarity

景观结构和气候在多大程度上控制流域水文响应？了解这种关系对于开发流域分类系统是必要的，该系统可以帮助建立低维和可证伪的水文模型，并更可靠地预测未测量流域的响应。我们建议开发和测试一种基于无量纲指数的流域水文学统一相似性理论，该理论既能捕捉景观的内部结构（地貌、土壤学和植被模式），也能捕捉主流气候特征。该研究的创新之处在于，我们将(i)将自下而上和自上而下的维度分析应用于来自不同气候区域的大量美国流域的观测结果，以及（ii）在不确定性框架中对这些相似性测量进行区划，以得出未测量流域的水文行为约束。流域水文学的统一相似理论将增强我们对水文循环中景观功能的基本理解，并将促进技术的发展，从而允许在流域尺度上对水预算进行综合分析，以及生态系统干扰和土地利用变化的影响。主要的研究假设是，通过关注景观水文过程的地貌和生态控制，可以进一步了解流域尺度的水文响应。最终的建议目标是提高我们对流域尺度上的流动过程的基本理解。构建这样一个全新的流域水文学相似理论，包括相关的一套模型，将在大范围的空间和时间尺度上为水文驱动机制提供新的见解。了解水文模型所需的复杂程度直接将我们的建议与美国业务预测界的当前问题联系起来。该提案包括在美国三个不同机构的三个不同部门的合作研究环境中对研究生进行高级水文建模和综合的培训。

To what extents do landscape structure and climate control watershed hydrologic response? Understanding this relationship is necessary to develop a watershed classification system that can help to build low-dimensional and falsifiable hydrologic models and more reliably predict the response of ungauged basins. We propose to develop and test a unifying similarity theory of watershed hydrology based on dimensionless indices that capture both the internal structure of landscapes (geomorphology, pedology and vegetation patterns) and prevailing climate characteristics. The innovation of the research lies in the fact that we will (i) apply bottom-up as well as top-down dimensional analyses to observations from a large number of U.S. watersheds in various climate regions, and (ii) regionalize these similarity measures in an uncertainty framework to derive constraints on hydrologic behavior in ungauged basins. This unifying similarity theory of watershed hydrology will enhance our fundamental understanding of landscape functioning in the hydrological cycle and will promote the development of techniques that permit an integrated analysis of water budgets at the watershed scale, as well as of the effects of ecosystem disturbance and land use change. The main research hypothesis is that advancement in understanding watershed-scale hydrologic response is possible by focusing on the geomorphologic and ecologic controls on hydrological processes of landscapes. The ultimate proposal objective is to improve our fundamental understanding of flow processes at the watershed-scale. Constructing such a novel similarity theory of watershed hydrology, including an associated suite of models, will provide new insights into the hydrologic driving mechanisms at a wide range of space and time scales. Understanding the required level of complexity of hydrologic models directly links our proposal to current questions of the operational forecasting community in the United States. The proposal includes graduate training in advanced hydrologic modeling and synthesis in a collaborative research environment across three different departments at three different institutions in the United States.