Estimating storm erosion with a rainfall simulator

Abstract

Estimating storm erosion with a rainfall simulator. Can. J. Soil Sci. 77: 669-676. Interpreting soil loss from rainfall simulators is complicated by the uncertain relationship between simulated and natural rainstorms. Our objective was to develop and test a method for estimating soil loss from natural rainfall using a portable rainfall simulator (1 m 2 plot size). Soil loss from 12 rainstorms was measured on 144-m 2 plots with barley residue in conventional tillage (CT), reduced tillage (RT) and zero tillage (ZT) conditions. A corresponding "simulated" soil loss was calculated by matching the simulator erosivity to each storm's erosivity. High (140 mm h -1 ) and low (60 mm h -1 ) simulation intensities were examined. The best agreement between simulated and natural soil loss occurred using the low intensity, after making three adjustments. The first was to compensate for the 38% lower kinetic energy of the simulator compared with natural rain. The second was for the smaller slope length of the simulator plot. The third was to begin calculating simulator erosivity only after runoff began. After these adjustments, the simulated soil loss over all storms was 99% of the natural soil loss for CT, 112% for RT and 95% for ZT. Our results show that rainfall simulators can successfully estimate soil loss from natural rainfall events. . Les déperditions correspondantes en conditions simulées étaient calculées en appariant les valeurs d'érosivité du simulateur au pouvoir érosif réel de chaque épisode pluvial. On utilisait une forte (140 mm h -1 ) et une basse (60 mm h -1 ) intensité de précipitations simulées. La meilleure concordance entre les déperditions de sol causées entre les pluies réelles et les pluies simulées s'observait au régime d'intensité pluviale inférieure, moyennant toutefois 3 corrections, la première, pour compenser la moindre (38 %) énergie cinétique du simulateur par rapport aux précipitations naturelles; le second pour tenir compte de la pente plus courte de la parcelle sous simulateur de pluie, tandis que la troisième consistait à ne commencer à calculer l'érosivité en régime simulé qu'après le début du ruissellement. Moyennant ces trois corrections, les déperditions de sol en simulation, tous épisodes pluviaux confondus, correspondaient à 99 % des déperditions par pluie naturelle observées en régime TC, à 112 % en régime TR et à 95 % en régime CST. Il semble que les simulateurs de pluie permettent parfaitement d'estimer les déperditions de sol causées par les épisodes de pluie naturelle.

Nutrient transfer by runoff from sewage sludge amended soil under simulated rainfall

“…The rainfall simulator used for these experiments was derived from the Guelph Rainfall Simulator II which was initially developed for erosion studies (Nolan et al, 1997;Tossell et al, 1987). The simulator is mobile, can be adapted to the slope and is supplied in water with a pump.…”

“…In order to study the sediment transport capacity of runoff, some authors have also used a runoff simulator on 10-m-length plots (Asseline et al, 1993), but this does not take into account the kinetic energy of raindrops, which is a crucial factor in soil particles detachment and pollutants losses from soil. Rainfall simulation has been developed for several years, initially for infiltration or erosion studies (Mc Isaac and Mitchell, 1992;Nolan et al, 1997). Such simulations provide control on intensity, frequency and duration of precipitation on both field and laboratory studies.…”

Hydrological Modelling Using a Rainfall Simulator over an Experimental Hillslope Plot

“…For this, one requires the historical rainfall climatology records to select the desirable rainfall duration and intensity for the simulation. A well-adopted procedure is to choose a defined precipitation intensity, then run the simulator till steady state runoff is achieved or for a specified time [2]. Moreover, in hillslope hydrological studies, the additional problem of the incorporation of macropore-dominated processes has to be tackled.…”

Soil hydrological and erosional responses in areas of woody encroachment, pasture and woodland in semi-arid Australia

“…inter-patches) to ensure resource movement and transfer within the system to maintain higher productivity patches, as proposed by Noy-Meir (1973). However, it is important to consider the scale at which resource transfer occurs: in woody vegetation (i.e.…”

“…In arid and semi-arid environments, where temporal and spatial distribution of rainfall is highly variable, rainfall simulation allows measurements to be taken under controlled and repeatable conditions (of intensity and duration). However, the interpretation of simulator measurements can be complicated by the uncertain relationship between the erosivity of simulated and natural rainstorms (Nolan et al, 1997), and the results only apply to the level of rainfall that is simulated. Measurements of runoff and erosion from small plots cannot be directly extrapolated to field conditions (Hamed et al, 2002).…”