Total water storage dynamics in response to climate variability and extremes: Inference from long-term terrestrial gravity measurement
Total water storage dynamics in response to climate variability and extremes: Inference from long-term terrestrial gravity measurement
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DOI：
10.1029/2011jd016472
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发表时间：
2012-04-27
影响因子：
4.4
通讯作者：
Guentner, Andreas
中科院分区：
文献类型：
--
作者：
Creutzfeldt, Benjamin;Ferre, Ty;Guentner, Andreas
陆地储水量是水循环的基本要素，是地表-大气相互作用的关键状态变量。然而，如何对不同的储水隔间进行综合的、超越点尺度的储水测量是一个挑战。在这项研究中，我们通过高精度超导重力仪在德国南部的一个水源集水区观测，探索了10年时间序列的总储水量变化。结合水文气象资料，研究了重力引起的蓄水量变化、气候和河流流量之间的关系。重力仪观测到的不同季节的水分储存动态与气象强迫，特别是蒸散发密切相关。年内蓄水量变化表明，在年尺度上蓄水量平均为零的简化假设对该集水区是不成立的。在事件尺度上，重力仪提供了可用的地下蓄水能力的测量，这对径流预测很有用。在2003年中欧干旱期间，重力仪的数据显示了蓄水的严重枯竭和持续数年的长期恢复。与点测量或不同的环境指数相比，我们的研究结果表明，深度积分重力仪测量可以更全面地了解水文系统对气候变率和极端事件的动态响应。鉴于重力仪在基础设施和测量方面的成本相当大，我们建议在水文气象监测网的选定地点战略性地部署重力仪。
Terrestrial water storage is a basic element of the hydrological cycle and a key state variable for land surface-atmosphere interaction. However, measuring water storage in a comprehensive way for different storage compartments and beyond the point scale is a challenge. In this study, we explore a 10-year time series of total water storage changes derived from high-precision superconducting gravimeter observations in a headwater catchment in Southern Germany. In combination with hydro-meteorological data, we examine the relationship between gravity-derived water storage changes, climate, and river discharge. Distinct seasonal water storage dynamics observed by the gravimeter are strongly related to the meteorological forcing, in particular evapotranspiration. Intra-annual water storage variations demonstrate that the simplifying assumption of water storage averaging to zero at the annual scale is not valid for this catchment. At the event-scale, gravimeters provide a measure of the available subsurface water storage capacity, which can be useful for runoff prediction. During the Central European drought in 2003, the gravimeter data show a strong depletion of water storage and a long-term recovery that extended over a period of several years. In comparison to point measurements or different environmental indices, our findings suggest that depth-integrated gravimeter measurements give a more complete picture of the dynamics of a hydrologic system in response to climate variability and extremes. In view of the considerable costs of gravimeters concerning the infrastructure and measurements, we suggest the strategic deployment of gravimeters at selected sites of hydro-meteorological monitoring networks.