Temporal stability of soil moisture in a large-field experiment in Spain
Temporal stability of soil moisture in a large-field experiment in Spain
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DOI：
10.2136/sssaj2003.1647
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发表时间：
2003-11-01
影响因子：
2.9
通讯作者：
Ceballos, A
中科院分区：
文献类型：
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作者：
Martínez-Fernández, J;Ceballos, A
在这里，我们分析了位于Duero盆地（西班牙）中部1285公里(2)区域的土壤水分含量的时间稳定性。利用由23个土壤湿度监测站（remmedhus）组成的网络（1999年6月至2002年5月）36个月的数据。在每个站点，每两周使用时域反射仪（TDR）在剖面底部的不同深度测量土壤水分。从水文的角度来看，这些站点彼此独立，并根据地理和土壤学标准在空间上分布。结果清楚地显示了哪些台站是湿和干条件的代表，以及代表性台站在最极端情况下的持久性。稳定性模式的时间演化表明，在所分析的时期内，稳定性模式具有相当程度的持久性。在分析的所有深度（5,25,50和100 cm）中，代表干燥条件的站点比在湿区确定的站点稳定得多。总体而言，在整个调查过程中，土壤水分含量表现出相当大的时间稳定性。然而，在使用的测量范围内，平均土壤湿度与方差之间存在明显的相关性（r = 0.85）。因此，土壤干燥时的时间稳定性总是高于含水量高时的时间稳定性。还注意到，时间稳定性最低的时期与从干向湿过渡的情况相吻合。就时间稳定性而言，关键时期是剖面中发生水补给的时期。
Here we analyze the temporal stability of the soil moisture content in an area of 1285 km(2) located in the central sector of the Duero basin (Spain). The data from a network consisting of 23 soil moisture-measuring stations (REMEDHUS) over a period of 36 mo (from June 1999 to May 2002) were used. At each station, soil moisture was measured fortnightly, using time domain reflectometry (TDR), at different depths to the bottom of the profile. From the hydrological point of view, the stations are independent from one another and were distributed in space using physiographic and pedological criteria. The results clearly show which stations are representative of wet and dry conditions and the persistence of the representative stations under even the most extreme situations. The temporal evolution of the stability patterns points to a considerable degree of persistence during the periods analyzed. The stations representative of dry conditions are seen to be much more stable at all the depths analyzed (5, 25, 50, and 100 cm) than those identified within the wet sector. Overall, the soil moisture content showed considerable temporal stability throughout of the investigation. However, a clear correlation was observed between mean soil moisture and variance (r = 0.85) across the range of measurements used. Accordingly, temporal stability is always higher when the soils are dry than when the water content is high. It was also observed that the periods with the lowest temporal stability coincided with situations involving the transition from dry to wet. The critical periods in terms of temporal stability are those in which the recharge of water in the profile occurs.