Potential Impacts of Prospective Climate Change on Groundwater Recharge in the Western United States

美国西部的地下水抽取是该地区水资源战略的重要组成部分。补给估算方法包括水平衡核算、地下水模拟、遥感、观测方法和环境示踪剂分析。该项目将召集一组调查人员，综合目前对西部地区补给的了解，以及未来几十年西部地区如何应对气候变化。在美国地质勘探局区域含水层系统分析项目下，该综合将建立在先前量化美国主要含水层系统的工作基础上。该综合将(1)利用该地区不同地区的补给控制及其对气候强迫敏感性的基于地理目标过程的研究；(2)利用最近可获得的动态缩小尺度的气候变化预估；(3)高分辨率水平衡研究和模型分析的融水过程探索结果。这些方法将用于加强对地下水补给的估计（估计不确定性），并将制定一份详细的研究需求清单，以便对整个地区的地下水补给进行更可靠的估计。该项目与美国地质勘探局约翰·韦斯利·鲍威尔中心科学委员会合作。该项目将大大提高对地下水补给控制的区域知识及其对美国西南部区域水可持续性的影响。通过综合现有知识以及最佳的分析和再分析方法，该项目将确定区域地下水补给的新方法（和更好的估计）。该项目还将通过为长期分析提供改进的基础，对西南地区的水资源和水管理战略产生重大影响。

Groundwater withdrawals in the western US are a critical component of the water resources strategy for the region. Recharge estimation methods include water balance accounting, groundwater modeling, remote sensing, observational methods and environmental tracer analysis. This project will assemble a team of investigators to synthesize current understanding of recharge in the West and how it may respond to climate change in the coming decades. The synthesis will build on previous work that quantified major aquifer systems within the United States under the USGS-Regional-Aquifer-System-Analysis program. The synthesis will (1) draw upon geographically targeted process-based studies of recharge controls and their sensitivity to climatic forcing in various parts of the region; (2) take advantage of recently available dynamically downscaled climate-change projections; (3) meld process-exploring results from high-resolution water balance studies and modeling analyses. These approaches will be used to develop enhanced estimates of groundwater recharge (with estimated uncertainties) and a detailed list of research needs will be developed for more robust estimates of groundwater recharge across the region. This project is cooperative with the USGS John Wesley Powell Center Science Board. This project will significantly advance regional knowledge of the controls on groundwater recharge and the impact this has on regional water sustainability for the US southwest. By synthesizing the state of knowledge as well as the best methods of analysis and reanalysis, the project will define new methods (and better estimates) of regional scale groundwater recharge. The project will also significantly impact water resource and water management strategy for the southwest by providing an improved basis for long timescale analysis.