Evaporation from bare soil in a temperate humid climate—measurement using micro-lysimeters and time domain reflectometry
Evaporation from bare soil in a temperate humid climate—measurement using micro-lysimeters and time domain reflectometry
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DOI：
10.1016/0168-1923(94)02215-6
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发表时间：
1995-08
影响因子：
6.2
通讯作者：
F. Plauborg
中科院分区：
文献类型：
--
作者：
F. Plauborg
在湿润地区，土壤蒸发是影响土壤耕作和生长季早期灌溉时机的重要因素。用微型溶渗仪直接测量了壤土的蒸发。日测量精度约为±0.5 mm H2O day−1。微渗法在高降水期不适用。使用时域反射法（TDR）测量土壤含水量进行了研究，使用人工解释的痕迹。当使用长度为50 cm的探针时，TDR每日测量计算的土壤含水量变化精度约为1.3 mm H2O。然而，通过使用轨迹的自动解释，可以获得更高的精度。根据水分平衡方程计算的裸地日蒸发量和用TDR测量的土壤含水量与用微溶渗仪测量的结果进行了比较。TDR技术适用于估算0 ~ 50 cm土壤剖面上的土壤含水量，且在剖面较低深度处停止排水。在春季土壤完全湿润后的13天干燥期，蒸发量约为26毫米。在季节后期的23天干燥期，裸露土壤的蒸发量约为30毫米。尽管0-50 cm剖面土壤含水量在第二次干燥期开始时远低于田间容量，但两期累积蒸发量均相当高，分别相当于第一次和第二次干燥期累积潜在蒸发量的65%和50%左右。
In humid areas soil evaporation is an important factor in relation to soil tillage and timing of irrigation early in the growing season. Direct measurements of evaporation from a loamy sand were made using micro-lysimeters. The accuracy of daily measurement was about ± 0.5 mm H2O day−1. The micro-lysimeter method was not valid in periods with high precipitation. The use of time domain reflectometry (TDR) for measuring soil water content was investigated using a manual interpretation of the trace. The precision of changes in soil water content calculated from daily measurements with TDR was about 1.3 mm H2O, when using probes of 50 cm length. However, improved precision may be obtained by the use of an automatic interpretation of the trace. Estimates of daily evaporation from bare soil calculated from the water balance equation and measurements of soil water content with TDR were compared with measurements with micro-lysimeters. The TDR technique was suitable for estimating bare soil evaporation when the soil water content was integrated over a 0–50 cm soil profile and drainage had ceased at the lower depths of the profile. Evaporation during a 13 day drying period in spring, just after the soil had been fully rewetted, was about 26 mm. During a 23 day drying period later in the season the evaporation from the bare soil was about 30 mm. In both periods the accumulated evaporation was rather high and equivalent to about 65% and 50% of the accumulated potential evapotranspiration in the first and second drying period, respectively, even though the soil water content in the 0–50 cm profile was well below field capacity at the beginning of the second drying period.