Temporal stability of soil moisture spatial variability at two scales and its implication for optimal field monitoring
Temporal stability of soil moisture spatial variability at two scales and its implication for optimal field monitoring
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DOI：
10.5194/hessd-4-1185-2007
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发表时间：
2007-05
期刊：
影响因子：
--
通讯作者：
X. Zhou;Henry Lin;Qing Zhu
中科院分区：
文献类型：
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作者：
X. Zhou;Henry Lin;Qing Zhu
抽象的。土壤水分空间分布是描述和模拟多尺度水分运动的重要组成部分。在宾夕法尼亚州中部7.9公顷的页岩丘陵流域，通过对分布在该流域的77个站点的全年监测，研究了土壤水分在多个深度上的空间分布的时间稳定性。对于这种具有不同土壤和地貌的集水区，将土壤信息整合到时间稳定性评估中，为获取平均土壤水分提供了更准确的代表性监测点的位置。土壤水分在沼泽尺度和集水区尺度上的时间稳定性格局与流域尺度相似，表明沼泽可以作为流域土壤水分动态研究的代表性单元。该流域土壤水分变异性的时间稳定性随空间和季节变化而变化。流域西北部和东南部的时间稳定性较好，而河流附近和部分沼泽区的时间稳定性较差。土壤水分的空间分布在雨季较稳定，但在过渡期(即干旱期或补给期)较不稳定。时间稳定性概念有助于现场监测点和抽样策略的优化设计。另一方面，时间上不稳定的站点提供了关于土壤水分空间变异性背后的水文过程的见解。
Abstract. Soil moisture spatial distribution is a key component in characterizing and modeling water movement at multiple scales. The temporal stability of soil moisture spatial distribution at multiple depths was investigated at the 7.9-ha Shale Hills Catchment in central Pennsylvania with a year-round monitoring of 77 sites distributed across the catchment. For this catchment with heterogeneous soils and landforms, integration of soils information into the temporal stability assessment provided a more accurate location of representative monitoring sites for capturing mean soil moisture. The temporal stability pattern of soil moisture at the swale scale was similar to that at the catchment scale, suggesting that the swale could be used as a representative unit in the catchment study in terms of mean soil moisture dynamics. The temporal stability of soil moisture variability in this catchment varied over space and seasons. Temporally stable sites were found in the northwestern and southeastern parts of the catchment, while the areas near the stream and some swale areas had lower temporal stability. The spatial distribution of soil moisture was more stable over time during wet seasons, but less stable during transitional periods (i.e. drying or recharging periods). The temporal stability concept helps the optimal design of field monitoring sites and sampling strategies. On the other hand, the temporally unstable sites provide insights regarding the hydrological processes behind the spatial variability of soil moisture.