Does the accuracy of fine-scale water level measurements by vented pressure transducers permit for diurnal evapotranspiration estimation?
Does the accuracy of fine-scale water level measurements by vented pressure transducers permit for diurnal evapotranspiration estimation?
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DOI：
10.1016/j.jhydrol.2013.03.001
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发表时间：
2013-04
影响因子：
6.4
通讯作者：
Z. Gribovszki;P. Kalicz;J. Szilágyi
中科院分区：
文献类型：
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作者：
Z. Gribovszki;P. Kalicz;J. Szilágyi
基于日水位(地表或地下水)波动的蒸散(ET)估算方法对测量精度很敏感(McLaughlin和Cohen，2011年；Cuevas等人，2010年)。水位波动通常由不同设计和精度的压力传感器测量。可用的总压传感器需要补偿由气压传感器提供的气压变化。最近，McLaughlin和Cohen(2011)以及Cuevas等人。(2010)分析了这类传感器对数据的“热伪影”，质疑在非缓冲热模式下的次日水位测量在估计昼夜ET时的适用性。原则上，类似的问题不应该出现在所谓的排气式压力传感器上。借助人工辅助测量，验证了排气式压力传感器获得超细尺度(时间分辨率为1-10min)的水汽和地下水位数据的准确性。通过对同期水位和温度数据的统计分析，检验了热效应。结果支持排气式压力传感器的无热伪影特性，因此在提供适当的维护和定期校准的情况下，它们适合用于昼夜ET估计目的。在缺乏这种措施的情况下，日温度变化也会导致排气式压力传感器读数的误差。
Evapotranspiration (ET) estimation methods based on diurnal water level (surface or groundwater) fluctuations are sensitive to measurement accuracy (McLaughlin and Cohen, 2011; Cuevas et al., 2010). Water level fluctuations are often measured by pressure transducers of varying design and precision. Available total pressure transducers require a compensation for barometric pressure change supplied by barometric pressure transducers. Recently McLaughlin and Cohen (2011) as well as Cuevas et al. (2010) analyzed the ‘thermal artifacts’ of such transducer-pair data questioning the applicability of sub-daily water level measurements in non-buffered thermal mode for diurnal ET estimation. Similar problems should not, in principle, occur for so-called vented pressure transducers. With the help of ancillary manual measurements, this study verifies the accuracy of vented pressure transducer obtained ultra-fine scale (temporal resolution of 1–10min) stream- and groundwater level data. Thermal effects were examined by a statistical analysis of concurrent water level and temperature data. The results support the thermal artifact-free nature of vented pressure transducers and therefore their suitability for diurnal ET estimation purposes when proper maintenance and periodic calibrations are provided. In the lack of such measures, diurnal temperature changes can induce errors in vented pressure transducer readings as well.