CREST

The Coupled Routing and Excess STorage (CREST) distributed hydrological model is a hybrid modeling strategy that was recently developed by the University of Oklahoma (http://hydro.ou.edu) and NASA SERVIR Project Team. CREST simulates the spatiotemporal variation of water and energy fluxes and storages on a regular grid with the grid cell resolution being user-defined, thereby enabling global- and regional-scale applications. The scalability of CREST simulations is accomplished through sub-grid scale representation of soil moisture storage capacity (using a variable infiltration curve) and runoff generation processes (using linear reservoirs). The CREST model was initially developed to provide online global flood predictions with relatively coarse resolution, but it is also applicable at small scales, such as single basins. This README file and the accompanying code concentrates on and tests the model at the small scale. The CREST Model can be forced by gridded potential evapotranspiration and precipitation datasets such as, satellite-based precipitation estimates, gridded rain gauge observations, remote sensing platforms such as weather radar, and quantitative precipitation forecasts from numerical weather prediction models. The representation of the primary water fluxes such as infiltration and routing are closely related to the spatially variable land surface characteristics (i.e., vegetation, soil type, and topography). The runoff generation component and routing scheme are coupled, thus providing realistic interactions between atmospheric, land surface, and subsurface water.耦合径流与过剩存储（Coupled Routing and Excess STorage, CREST）分布式水文模型是由俄克拉荷马大学（http://hydro.ou.edu）与NASA SERVIR项目团队新近开发的混合建模策略。CREST可在用户自定义分辨率的规则网格上模拟水、能量通量及存储量的时空变化，从而支持全球及区域尺度的应用场景。该模型的模拟可扩展性通过亚网格尺度的土壤水分存储能力表征（采用可变入渗曲线）与产流过程（采用线性水库）得以实现。CREST模型最初旨在提供相对粗分辨率的全球在线洪水预报服务，但其同样适用于小尺度应用，例如单一流域。本README文件及配套代码聚焦并在小尺度场景下对该模型开展测试。CREST模型可由网格化潜在蒸散发与降水数据集驱动，这类数据集涵盖卫星反演降水产品、网格化雨量站观测数据、天气雷达等遥感平台数据，以及数值天气预报模型产出的定量降水预报产品。主要水通量（如入渗与径流）的表征与空间异质性地表特征（即植被、土壤类型与地形）密切相关。产流模块与汇流方案相互耦合，从而实现大气、地表与地下水之间的真实相互作用。