Patault Edouard, Alary Claire, Franke Christine, Gauthier Arnaud, Abriak Nor-Edine
IMT Lille Douai, Univ. Lille, EA 4515 - LGCgE - Civil Engineering and Environmental Department, F-59000 Lille, France.
MINES ParisTech, PSL Research University, Center of Geosciences, 35 rue Saint-Honoré, 77305 Fontainebleau Cedex, France.
Heliyon. 2019 Mar 26;5(3):e01407. doi: 10.1016/j.heliyon.2019.e01407. eCollection 2019 Mar.
A high-frequency monitoring station was implemented at the outlet of the small catchment of the Pommeroye (0.54 km) in Northern France to study erosion by runoff and hydro-sedimentological responses to heavy rainfall events in the context of Quaternary loess deposits. The aim of this experimental work is to assess the temporal variability of sediment yield and to identify the factors controlling the hydro-sedimentary response. To achieve this goal, statistical and hydro-sedimentary dynamic analyses were performed. During two years of monitoring (April 2016-April 2018), 48 flood events were recorded. The specific sediment yield (SSY) is highly variable and was evaluated to 29.4-70 t km yr which is conventional for the study region. Most of the sediment yield was produced in winter (55%) and autumn (42%). Only 3% of SSY were produced during spring and summer periods. According to our results, only 6% of the erosive events are responsible for the transport of more than 40% of the sediment flux recorded at the outlet. This underlines the temporal variability of the hydro-sedimentary production in small agricultural catchments for which most of the hydro-sedimentary flux is produced during a limited number of events. The results of statistical analyses show that the total amount of rainfall and the duration of a rainfall episode are the main controlling factors on the hydro-sedimentary response. Our results also suggest that the rainfall kinetic energy better reflects the sediment detachment, and that the 48 h-antecedent rainfall is not linked to the hydro-sedimentary response.
在法国北部的庞莫罗耶小流域（0.54平方千米）出口处设置了一个高频监测站，以研究第四纪黄土沉积背景下径流侵蚀及对暴雨事件的水沙学响应。这项实验工作的目的是评估产沙量的时间变化，并确定控制水沙响应的因素。为实现这一目标，进行了统计分析和水沙动力学分析。在两年的监测期（2016年4月至2018年4月）内，记录了48次洪水事件。单位面积产沙量（SSY）变化很大，经评估为29.4 - 70吨/平方千米·年，这在研究区域内是常见的。大部分产沙量发生在冬季（55%）和秋季（42%）。春季和夏季的产沙量仅占SSY的3%。根据我们的结果，只有6%的侵蚀事件导致了出口处记录的超过40%的泥沙通量的输移。这突出了小型农业流域水沙产出的时间变化性，在这类流域中，大部分水沙通量是在有限次数的事件中产生的。统计分析结果表明，降雨总量和降雨历时是水沙响应的主要控制因素。我们的结果还表明，降雨动能能更好地反映泥沙剥离情况，且前期48小时降雨量与水沙响应无关。
