Submarine groundwater discharge in tidal flats revealed by space-borne synthetic aperture radar
Submarine groundwater discharge in tidal flats revealed by space-borne synthetic aperture radar
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DOI：
10.1016/j.rse.2010.11.009
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发表时间：
2011-02
影响因子：
13.5
通讯作者：
Duk‐jin Kim;W. Moon;Guebuem Kim;Sang-Eun Park;Hyoseong Lee
中科院分区：
文献类型：
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作者：
Duk‐jin Kim;W. Moon;Guebuem Kim;Sang-Eun Park;Hyoseong Lee
大多数太空传感器无法探测地下特征。地下水是典型的地下特征，其向沿海海域的排放在运输陆地化学成分和为各种动植物提供栖息地方面起着重要作用。这是第一篇利用星载合成孔径雷达（SAR）报道滩地海底地下水排放（SGD）观测证据的论文。潮滩是由高水分饱和的沉积物和水坑组成的。利用SAR系统对这些浅水水坑进行了有效成像。由于水面的镜面反射，SAR图像中的低雷达后向散射通常表明水坑的存在。通过将TerraSAR-X和RADARSAT-2两种星载SAR系统的雷达后向散射系数与IEM和Oh两种理论散射模型的后向散射系数进行比较，证明了这种效应。在潮滩上部观测到较大、分布较广的带状水坑，证实其与地下水的排出有关。本研究结果表明，SAR可以作为观测和确定大型潮滩可能地下水流量的面积分布的有力工具，而传统的地下水流量测量工具或调查技术通常难以探测到这些分布。我们坚信，这项技术可以大大减少在潮滩确认SGD的现场工作。
Most space-borne sensors cannot detect subsurface features. Groundwater is a typical subsurface feature, and its discharge to coastal ocean waters plays an important role in transporting terrestrial chemical constituents and providing habitats for various species of fauna and flora. This is the first paper to report observational evidence for submarine groundwater discharge (SGD) in tidal flats using space-borne synthetic aperture radar (SAR). Tidal flats are composed of high-moisture-saturated sediments and water puddles. These shallow water puddles were imaged effectively by using SAR systems. The presence of water puddles is usually indicated by low radar backscatter in SAR images due to specular reflections on the water surface. This effect was proved by comparing radar backscattering coefficients obtained from two space-borne SAR systems, TerraSAR-X and RADARSAT-2, with those obtained from two theoretical scattering models, IEM and Oh model. We observed relatively large, widely distributed water puddles in belt shape along the upper parts of the tidal flat, which were confirmed to be related to the discharge of groundwater. The results of this research suggest that SAR can be a powerful tool for observing and determining the areal distributions of possible groundwater discharge in large tidal flats, which is normally difficult to detect with traditional measurement tools or survey techniques for groundwater discharge. We firmly believe that this technique can reduce significantly the efforts of field work to confirm SGD in tidal flats.