4.5 Article

The influence of groundwater abstraction on interpreting climate controls and extreme recharge events from well hydrographs in semi-arid South Africa

期刊

HYDROGEOLOGY JOURNAL
卷 29, 期 8, 页码 2773-2787

出版社

SPRINGER
DOI: 10.1007/s10040-021-02391-3

关键词

Groundwater recharge; Teleconnections; Abstraction; Semi-arid; South Africa

资金

  1. NERC-ESRCDFID UPGro programme [NE/M008932/1, NE/M008622/1]
  2. CGIAR Research Program on Water, Land and Ecosystems (WLE)
  3. British Geological Survey NC-ODA [NE/R000069/1]
  4. UK Natural Environment Research Council [NE/P017819/1]
  5. Ministry of Foreign Affairs of Denmark via the Danida Fellowship Centre

向作者/读者索取更多资源

This study analyzed 21 hydrographs from semi-arid South Africa, categorizing them into four types through hierarchical cluster analysis. It found that the autocorrelation of different hydrograph types changes over increasing timescales, with increasingly subdued responses to rainfall. Type C1 strongly relates to rainfall, while C4 notably responds to only a single extreme event in 2000 and has limited relationship with rainfall.
There is a scarcity of long-term groundwater hydrographs from sub-Saharan Africa to investigate groundwater sustainability, processes and controls. This paper presents an analysis of 21 hydrographs from semi-arid South Africa. Hydrographs from 1980 to 2000 were converted to standardised groundwater level indices and rationalised into four types (C1-C4) using hierarchical cluster analysis. Mean hydrographs for each type were cross-correlated with standardised precipitation and streamflow indices. Relationships with the El Nino-Southern Oscillation (ENSO) were also investigated. The four hydrograph types show a transition of autocorrelation over increasing timescales and increasingly subdued responses to rainfall. Type C1 strongly relates to rainfall, responding in most years, whereas C4 notably responds to only a single extreme event in 2000 and has limited relationship with rainfall. Types C2, C3 and C4 have stronger statistical relationships with standardised streamflow than standardised rainfall. C3 and C4 changes are significantly (p < 0.05) correlated to the mean wet season ENSO anomaly, indicating a tendency for substantial or minimal recharge to occur during extreme negative and positive ENSO years, respectively. The range of different hydrograph types, sometimes within only a few kilometres of each other, appears to be a result of abstraction interference and cannot be confidently attributed to variations in climate or hydrogeological setting. It is possible that high groundwater abstraction near C3/C4 sites masks frequent small-scale recharge events observed at C1/C2 sites, resulting in extreme events associated with negative ENSO years being more visible in the time series.

作者

我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。

评论

主要评分

4.5
评分不足

次要评分

新颖性
-
重要性
-
科学严谨性
-
评价这篇论文

推荐

暂无数据
暂无数据