Characterization of shifts in regional hydroclimatic conditions helps reduce negative consequences on agriculture, environment, economy, society, and ecosystem. This study assesses shifts in regional hydroclimatic conditions across the conterminous United States in response to climate change over the 21st century. The hydrological responses of five downscaled climate models from the Multivariate Adaptive Constructed Analogs data set ranging from the driest to wettest and least warm to hottest were simulated using the variable infiltration capacity (VIC) model. Shifts in regional hydroclimatic conditions at 8‐digit hydrologic unit scale (HUC8) were evaluated by the magnitude and direction of movements in the Budyko space. HUC8 river basins were then clustered into seven unique hydroclimatic behavior groups using the K‐means method. A tree classification method was proposed to illustrate the relationships between hydroclimatic behavior groups and regional characteristics. The results indicate that hydroclimatic responses may vary from a river basin to another, but basins in the same neighborhood follow a similar movement in the Budyko space. The systematic hydroclimatic behavior of river basins is highly associated with their regional landform, climate, and ecosystem characteristics. Most HUC8s with mountain, plateau, and basin landform types will likely experience less arid conditions. However, most HUC8s with Plain landform type behave differently according to the regional ecosystem and climate. This study provides a potential roadmap of shifts in regional hydroclimatic conditions of U.S. river basins, which can be used to improve regional preparedness and ability of various sectors to mitigate or adapt to the impacts of future hydroclimate change.

中文翻译：

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评估21世纪美国流域响应气候变化的区域性水文气候条件的变化

区域性水文气候条件变化的特征有助于减少对农业，环境，经济，社会和生态系统的负面影响。这项研究评估了整个21世纪美国响应气候变化的区域性水文气候条件的变化。使用可变渗透能力（VIC）模型，模拟了多变量自适应构造模拟物数据集中五个缩水气候模型的水文响应，其范围从最干燥到最湿，最不温暖到最热。通过Budyko空间中的运动幅度和方向评估了8位水文单位尺度（HUC8）上区域水气候条件的变化。然后，使用K-means方法将HUC8流域分为七个独特的水文气候行为组。提出了一种树的分类方法来说明水气候行为群与区域特征之间的关系。结果表明，不同流域的水文气候响应可能有所不同，但同一邻域的流域在Budyko空间中遵循相似的运动。流域的系统水文气候行为与其区域地貌，气候和生态系统特征高度相关。大多数具有山脉，高原和盆地地貌类型的HUC8可能会遇到较少的干旱条件。但是，大多数具有平原地貌类型的HUC8的行为根据区域生态系统和气候而有所不同。这项研究为美国河流域区域性气候气候条件的转变提供了潜在的路线图，