CMIP6-based Multi-model Streamflow Projections over the Conterminous US

This dataset presents an ensemble of streamflow projections based on the hydroclimate projections dataset supporting the SECURE Water Act Section 9505 Assessment for the US Department of Energy (DOE) Water Power Technologies Office (WPTO). The six-member General Climate Model (GCM) ensemble from the Coupled Models Intercomparison Project phase 6 (CMIP6) downscaled using statistical (i.e., DBCCA) and dynamical (i.e., RegCM) and bias-corrected using two meteorological reference observations (Daymet & Livneh) are driven through two calibrated hydrologic models (VIC & PRMS) to simulate projected future hydrologic responses. This leads to the production of an ensemble of hydroclimate projections, including total runoff (surface runoff and baseflow) for 1980–2019 baseline and 2020–2059 near-term future periods under multiple emission scenarios at 1/24° (~4 km) spatial resolution across the CONUS. The total runoff projections are routed through the Routing Application for Parallel computatIon of Discharge (RAPID) routing model to produce an ensemble of streamflow projections for both periods across 2.7 million NHDPlusV2 stream reaches in the CONUS.

本数据集基于支撑美国能源部（Department of Energy, DOE）水动力技术办公室（Water Power Technologies Office, WPTO）《安全水资源法案》第9505条评估的水文气候预测数据集，构建了径流预测集合。本研究采用耦合模式比较计划第六阶段（Coupled Models Intercomparison Project phase 6, CMIP6）的6成员通用气候模式（General Climate Model, GCM）集合，通过统计降尺度方法（即DBCCA）与动力降尺度方法（即RegCM）完成降尺度处理，并利用两套气象参考观测数据集（Daymet与Livneh）进行偏差校正；随后将校正后的数据驱动两个经过率定的水文模型（VIC与PRMS），以模拟未来水文响应过程。由此生成的水文气候预测集合涵盖1980–2019年基准期与2020–2059年近期未来时段的总径流（包括地表径流与基流），模拟在多排放情景下开展，空间分辨率为1/24°（约4 km），覆盖美国本土（Contiguous United States, CONUS）全域。总径流预测结果将通过并行径流演算模型（Routing Application for Parallel computatIon of Discharge, RAPID）进行汇流演算，最终生成覆盖美国本土270万条NHDPlusV2河道河段的两个时段径流预测集合。