Decoding groundwater level patterns and abrupt changes in Central and Southern California's alluvial regions

IF 4.9 Q2 ENGINEERING, ENVIRONMENTAL

Groundwater for Sustainable Development Pub Date : 2025-02-01 DOI:10.1016/j.gsd.2025.101409

Fabio Di Nunno, Francesco Granata

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Abstract

The variability in groundwater levels (GWL) in California's Central Valley and Southern California Coastal Basin, driven by climatic and hydrological shifts, poses significant challenges for ecosystems and agricultural sustainability. This study employs a dual-method approach, integrating the Seasonal Kendall (SK) test and the Bayesian Estimator of Abrupt Change, Seasonality, and Trend (BEAST) algorithm, to analyze long-term trends and abrupt shifts in GWL. The SK test reveals statistically significant declines in GWL across most wells, with particularly severe reductions observed in the Central Valley and the counties of San Bernardino and San Diego. For instance, well A5 in the Central Valley recorded a Z-value of 23.83 and a β of 2.36, marking acute groundwater depletion. Similarly, in San Bernardino County, wells S11 (Z = 24.09, β = 14.50) and S17 (Z = 24.20, β = 9.53) demonstrated alarming declines. These findings suggest that reduced recharge rates and intensified extraction are driving the depletion, which in turn threatens local ecosystems through diminished streamflows and wetland contraction. However, some wells exhibited rising GWL, attributed to localized recharge, underscoring the spatial heterogeneity of groundwater dynamics. BEAST analysis further identified both positive and negative abrupt changes in GWL, reflecting complex responses to environmental variability. While several wells recorded sharp drops in GWL, such as up to −7.48 m in the Central Valley and −44.00 m in Southern California, others demonstrated notable recoveries, including up to 4.20 m in the Central Valley and 9.31 m in Southern California. These results emphasize the urgent need for tailored groundwater management strategies that address both declining and rising trends, while accounting for seasonal variability. Adaptive water management practices, which are flexible and responsive to changing conditions, will be crucial to safeguarding ecosystem integrity and sustaining agricultural productivity.

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破解加州中南部冲积区地下水位模式和突变

在气候和水文变化的驱动下，加利福尼亚中央山谷和南加州沿海盆地地下水位（GWL）的变化对生态系统和农业可持续性构成了重大挑战。本研究采用双方法，结合季节性肯德尔（SK）检验和贝叶斯突变、季节性和趋势估计（BEAST）算法，分析了GWL的长期趋势和突变。SK测试显示，大多数井的GWL都有统计学上的显著下降，在Central Valley、San Bernardino和San Diego县的GWL下降尤为严重。例如，中央山谷A5井的z值为23.83，β值为2.36，标志着地下水严重枯竭。同样，在San Bernardino县，S11井（Z = 24.09, β = 14.50）和S17井（Z = 24.20, β = 9.53）也出现了惊人的下降。这些发现表明，补给率的降低和采掘的加剧正在推动水资源枯竭，从而通过减少河流流量和湿地收缩威胁当地生态系统。然而，部分井的GWL呈上升趋势，这与局部补给有关，凸显了地下水动态的空间异质性。BEAST分析进一步确定了GWL的正突变和负突变，反映了对环境变率的复杂响应。虽然有几口井的GWL急剧下降，如中央山谷的- 7.48米和南加州的- 44.00米，但其他井的GWL也出现了显著的恢复，包括中央山谷的4.20米和南加州的9.31米。这些结果强调，迫切需要制定量身定制的地下水管理战略，以应对下降和上升的趋势，同时考虑到季节变化。适应性水管理实践具有灵活性，能够对不断变化的条件作出反应，对于保护生态系统的完整性和维持农业生产力至关重要。

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来源期刊

Groundwater for Sustainable Development Social Sciences-Geography, Planning and Development

CiteScore

11.50

自引率

10.20%

发文量

152

期刊介绍： Groundwater for Sustainable Development is directed to different stakeholders and professionals, including government and non-governmental organizations, international funding agencies, universities, public water institutions, public health and other public/private sector professionals, and other relevant institutions. It is aimed at professionals, academics and students in the fields of disciplines such as: groundwater and its connection to surface hydrology and environment, soil sciences, engineering, ecology, microbiology, atmospheric sciences, analytical chemistry, hydro-engineering, water technology, environmental ethics, economics, public health, policy, as well as social sciences, legal disciplines, or any other area connected with water issues. The objectives of this journal are to facilitate: • The improvement of effective and sustainable management of water resources across the globe. • The improvement of human access to groundwater resources in adequate quantity and good quality. • The meeting of the increasing demand for drinking and irrigation water needed for food security to contribute to a social and economically sound human development. • The creation of a global inter- and multidisciplinary platform and forum to improve our understanding of groundwater resources and to advocate their effective and sustainable management and protection against contamination. • Interdisciplinary information exchange and to stimulate scientific research in the fields of groundwater related sciences and social and health sciences required to achieve the United Nations Millennium Development Goals for sustainable development.