RUI: Groundwater teleconnections with interannual to multidecadal climate variability

RUI：地下水遥相关与年际至数十年气候变化

• 批准号: 1316553
• 负责人: Jason Gurdak
• 金额: $ 32.19万
• 依托单位: San Francisco State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-08-15 至 2017-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1316553&HistoricalAwards=false
• 关键词: RUI; Groundwater; teleconnections; interannual; multidecadal

The potential effects of climate variability and change on water resources is a well recognized and urgent concern from the local to global scale ? one that has increasingly become a high priority for groundwater managers and policy makers. The strategic importance of groundwater to global water and food security will likely intensify under climate change as more frequent and intense climate extremes increase variability in precipitation, soil moisture, and surface-water availability. However, the reliable characterization and forecast of responses in groundwater to climate change is complicated by the complex, heterogeneous nature of global-scale atmospheric-ocean circulation systems that partially control interannual to multidecadal climate variability and associated periodic and reversible patterns in terrestrial hydrology. Natural climate variability on these time scales influences precipitation distribution in space and time, drought frequency and severity, snowmelt runoff, streamflow, and other hydrologic processes that can profoundly affect surface-water resources. Some studies have inferred teleconnections between global-scale atmospheric-ocean forcings and groundwater. Yet, few have established strong evidence of causal relation between interannual to multidecadal climate variability and recharge rates and mechanisms ? many important process-level questions remain. This project will fill this critical knowledge gap by testing the hypothesis that transient recharge rates and corresponding groundwater-level fluctuations respond to the complex, heterogeneous interactions of local-scale vadose zone processes and properties and global-scale atmospheric-ocean circulation systems. In particular, our research will quantifying the frequency, intensity, and phase relation of nonstationary signals in long-term climatic and hydrologic time series data from 15 of the most important U.S. Principal Aquifers, and correlate the teleconnections to the 6 leading atmospheric-ocean circulation systems that affect U.S. climate variability. We will evaluate constructive and destructive interference of teleconnection signals in precipitation, and the filtering in the vadose zone that dampens those signals, eventually producing an altered recharge time series. We will use this insight to evaluate the relative importance of the atmospheric-ocean circulation systems on transient recharge rates under future climate change scenarios. The expected results will have a broad impact because time-varying rates of recharge will improve local to national-scale groundwater models and sustainability studies. The project creates rich and engaging teaching, training, and learning experience for undergraduate and graduate students from underrepresented groups in STEM. Additionally, we establish a model collaboration that enhances research and education between students and faculty from non-Ph.D. and Ph.D. granting institutions.

从地方到全球，气候变异和变化对水资源的潜在影响是一个公认的紧迫问题。这一问题日益成为地下水管理者和决策者的高度优先事项。地下水对全球水和粮食安全的战略重要性可能会在气候变化下加剧，因为更频繁和更强烈的气候极端现象增加了降水、土壤湿度和地表水可用性的可变性。然而，地下水对气候变化的反应的可靠表征和预测由于全球尺度大气-海洋环流系统的复杂性和异质性而变得复杂，这些环流系统部分地控制着年际至数十年的气候变率以及陆地水文学中相关的周期性和可逆模式。这些时间尺度上的自然气候变异性影响降水在空间和时间上的分布、干旱的频率和严重程度、融雪径流、河川径流和其他水文过程，这些水文过程会对地表水资源产生深刻影响。一些研究推断全球尺度大气-海洋强迫与地下水之间存在遥相关。然而，很少有建立强有力的证据之间的因果关系的年际到几十年的气候变率和补给率和机制？许多重要的流程级问题仍然存在。该项目将通过检验以下假设填补这一关键的知识空白：瞬时补给率和相应的地下水位波动对当地规模的包气带过程和性质以及全球规模的大气-海洋环流系统的复杂、异质相互作用作出反应。特别是，我们的研究将量化来自15个最重要的美国主要含水层的长期气候和水文时间序列数据中非平稳信号的频率，强度和相位关系，并将遥相关与影响美国气候变化的6个主要大气-海洋环流系统相关联。我们将评估降水遥相关信号的建设性和破坏性干扰，以及在包气带中抑制这些信号的滤波，最终产生一个改变的补给时间序列。我们将利用这一认识来评估未来气候变化情景下大气-海洋环流系统对瞬时补给率的相对重要性。预期的结果将产生广泛的影响，因为随时间变化的补给率将改善地方到国家规模的地下水模型和可持续性研究。该项目为来自STEM代表性不足群体的本科生和研究生创造了丰富而引人入胜的教学，培训和学习经验。此外，我们建立了一个合作模式，加强了学生和教师之间的研究和教育，从非博士。和博士授予机构。