Estimating field-scale soil water dynamics at a heterogeneous site using multi-channel GPR
Estimating field-scale soil water dynamics at a heterogeneous site using multi-channel GPR
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DOI：
10.5194/hess-16-4361-2012
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发表时间：
2011-12
影响因子：
6.3
通讯作者：
Xicai Pan;Jiabao Zhang;Ping Huang;K. Roth
中科院分区：
文献类型：
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作者：
Xicai Pan;Jiabao Zhang;Ping Huang;K. Roth
我们探索了通过探地雷达(GPR)测量的时间序列来量化田间尺度土壤水分动态的可行性，GPR(大地穿透雷达)测量架起了点测量和野外测量之间的桥梁。我们在一块40m×50m的异质农田上工作，得到了一次暴雨后的雷达图时间序列。对这些数据进行分析，以同时产生(1)地下建筑的三维表示和(2)地表与反射边界之间的总土壤水量，该反射边界与相当均匀的沙基中存在的古沙丘或粘土包裹体有关。我们评估了这些量的精确度和准确度，结论是该方法足够灵敏地捕捉到在短期入渗事件中三维非均质土壤中土壤水分变化的空间结构。虽然该方法的灵敏度有待提高，但它已经提供了有用的信息来理解观测到的作物高度模式，并对该地点的土壤水分动态进行了洞察，包括蒸发的影响。
We explore the feasibility to quantify the field-scale soil water dynamics through time series of GPR (ground-penetrating radar) measurements, which bridge the gap between point measurements and field measurements. Working on a 40 m × 50 m area in a heterogeneous agricultural field, we obtain a time series of radargrams after a heavy rainfall event. The data are analysed to simultaneously yield (i) a three-dimensional representation of the subsurface architecture and (ii) the total soil water volume between the surface and a reflection boundary associated with the presence of paleo sand dunes or clay inclusions in a rather uniform sand matrix. We assess the precision and the accuracy of these quantities and conclude that the method is sensitive enough to capture the spatial structure of the changing soil water content in a three-dimensional heterogeneous soil during a short-duration infiltration event. While the sensitivity of the method needs to be improved, it already produced useful information to understand the observed patterns in crop height and it yielded insight into the dynamics of soil water content at this site including the effect of evaporation.