Monitoring spatiotemporal soil moisture changes in the subsurface of forest sites using electrical resistivity tomography (ERT)
Monitoring spatiotemporal soil moisture changes in the subsurface of forest sites using electrical resistivity tomography (ERT)
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使用电阻率断层扫描 (ERT) 监测森林地表下土壤湿度的时空变化
DOI：
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发表时间：
2022
影响因子：
1.5
通讯作者：
C. Kneisel
中科院分区：
文献类型：
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作者：
J. Fäth;Julius Kunz;C. Kneisel
干旱对森林树木死亡率的影响尚未完全了解。在气候变化的时代，了解土壤水分的小尺度分布及其随时间的变化是评估其供水的关键问题。然而，传统的方法，如采集土壤样本或安装数据记录仪，仅收集单个点或小土壤体积的参数。电阻率层析成像（ERT）是监测土壤水分变化的合适方法，但很少用于森林。这种方法被应用在两个森林站点在巴伐利亚州，德国获得高分辨率的数据的时间土壤水分变化。多年来（2015-2018/2020）在两个地点进行了地电测量（2D和3D），并与监测地块的土壤水分数据（基质势或体积含水量）进行了比较。与土壤水分数据高度相关的电阻率值的最大变化被发现在主要生根区。利用ERT数据，可以在几个方面跟踪时间趋势，例如干旱事件影响深度及其持续时间的年际增加，以及随着土壤湿度下降而沿着上升的电阻率值。结果表明，电阻率的变化是一个很好的替代季节和年际变化的土壤水分。因此，2D-和3D-ERT的建议作为相对不费力的方法，小空间尺度监测土壤水分变化的主要生根区和下层的森林网站。更高的空间和时间分辨率可以更好地了解树木的供水情况，特别是在干旱时期。
The effects of drought on tree mortality at forest stands are not completely understood. For assessing their water supply, knowledge of the small-scale distribution of soil moisture as well as its temporal changes is a key issue in an era of climate change. However, traditional methods like taking soil samples or installing data loggers solely collect parameters of a single point or of a small soil volume. Electrical resistivity tomography (ERT) is a suitable method for monitoring soil moisture changes and has rarely been used in forests. This method was applied at two forest sites in Bavaria, Germany to obtain high-resolution data of temporal soil moisture variations. Geoelectrical measurements (2D and 3D) were conducted at both sites over several years (2015–2018/2020) and compared with soil moisture data (matric potential or volumetric water content) for the monitoring plots. The greatest variations in resistivity values that highly correlate with soil moisture data were found in the main rooting zone. Using the ERT data, temporal trends could be tracked in several dimensions, such as the interannual increase in the depth of influence from drought events and their duration, as well as rising resistivity values going along with decreasing soil moisture. The results reveal that resistivity changes are a good proxy for seasonal and interannual soil moisture variations. Therefore, 2D- and 3D-ERT are recommended as comparatively non-laborious methods for small-spatial scale monitoring of soil moisture changes in the main rooting zone and the underlying subsurface of forested sites. Higher spatial and temporal resolution allows a better understanding of the water supply for trees, especially in times of drought.