A portable wind and rainfall simulator for in situ soil erosion measurements
A portable wind and rainfall simulator for in situ soil erosion measurements
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DOI：
10.1016/j.catena.2011.03.002
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发表时间：
2012-04
期刊：
影响因子：
6.2
通讯作者：
W. Fister;T. Iserloh;J. Ries;Reinhard-G. Schmidt
中科院分区：
文献类型：
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作者：
W. Fister;T. Iserloh;J. Ries;Reinhard-G. Schmidt
在具有模拟降雨能力的风洞中进行的实验室研究突出表明，在分析土壤侵蚀过程时必须考虑风与降雨之间复杂的相互作用。为了克服实验室研究的固有局限性，并进一步研究这些相互作用在可比的条件下，在现场，便携式风和降雨模拟器（PWRS）已经开发。本研究的目的是指定的风和降雨特性的PWRS和评估，如果其模拟质量和再现性是足够的比较土壤侵蚀研究在该领域。风速测量表明，存在一个厚度约为0.2m的预成形对数边界层。在隧道下方0.3m范围内，隧道内气流的均匀性是可接受的，最大标准偏差低于0.7ms−1。连续三次重复测量之间的风速的最大变化小于15%。无风降水的空间分布均匀性较差（CU =60%），但连续5次重复的重复性很好。大约90%的试验田经历的降雨变异性低于5%。模拟的雨滴粒径分布与计算的马歇尔-帕尔默分布（MPD）等降雨强度（平均偏差为2.1%）对应得很好。对于风致雨，上述参数均明显改善（CU= 76%，平均偏差=1.7%）。平均降雨强度在五次重复测量中也显示出非常低的变异性，无风降雨（平均强度96 mmh − 1）的标准差为0.31 mmh − 1，而风驱动降雨（平均强度88 mmh −1）的标准差为0.69 mmh − 1。总之，PWRS的测试结果是非常令人满意的，特别是考虑到物理限制，必须考虑到达到预期的便携性。这项研究中提出的分析表明，特别是风和雨的条件非常好的再现性。因此，PWRS应该是一个有用的装置，比较在现场土壤侵蚀测量，并支持收集定量数据的相对重要性，土壤剥离率之间的风蚀和水蚀，以及无风和风力驱动的降雨。
Laboratory research in wind tunnels with the capability of simulating rainfall highlighted the importance of considering the complex interactions between wind and rainfall in the analysis of soil erosion processes. In order to overcome the inherent limitations of laboratory research and to further investigate these interactions under comparable conditions in the field, a Portable Wind and Rainfall Simulator (PWRS) has been developed. The aim of this study was to specify the wind and rainfall characteristics of the PWRS and to evaluate if its simulation quality and reproducibility is adequate for comparative soil erosion studies in the field. Wind velocity measurements show that a pre-shaped logarithmic boundary layer with a thickness of about 0.2m exists. The uniformity of airflow across the tunnel is acceptable within the lower 0.3m of the tunnel with maximum standard deviations below 0.7ms−1. Maximum variability of wind velocities between three consecutive repetitions of the measurements is lower than 15%. The spatial rainfall distribution for windless rain show rather poor uniformity (Christiansen Uniformity (CU) coefficient=60%), but very good reproducibility in-between five consecutive replications. About 90% of the test plot experiences a variability of rainfall below 5%. Simulated drop size distributions correspond very well with calculated Marshal–Palmer Distributions (MPD) of equal rainfall intensities (mean deviation of 2.1%). For wind-driven rain both above mentioned parameters clearly improve (CU=76%, mean deviation=1.7%). The mean rainfall intensities show also very low variability between the five replications with standard deviations of 0.31mmh−1for windless rain (mean intensity 96mmh−1) and 0.69mmh−1for wind-driven rain (mean intensity 88mmh−1). In conclusion, test results of the PWRS are very satisfactory, especially considering the physical constraints, which have to be taken into account to reach desired portability. The analysis presented in this study suggests in particular very good reproducibility of wind and rain conditions. The PWRS should therefore be a useful device for comparative in situ soil erosion measurements in the field and support the gathering of quantitative data on the relative importance of soil detachment rates between wind and water erosion, as well as windless and wind-driven rainfall.