Development and testing of a large, transportable rainfall simulator for plot-scale runoff and parameter estimation

Abstract

Abstract. There is increased interest in the interplay between vegetation conditions and overland flow generation. The literature is unclear on this relationship and there is little quantitative guidance for modeling efforts. Therefore, experimental efforts are needed and these call for a lightweight transportable plot-scale (>10 m2) rainfall simulator that can be deployed quickly and quickly redeployed over various vegetation cover conditions. Accordingly, a variable intensity rainfall simulator and collection system was designed and tested in the laboratory and in the field. The system was tested with three configurations of common pressure washing nozzles producing rainfall intensities of 62, 43, and 32 mm h−1 with uniformity coefficients of 76, 65, and 62, respectively, over a plot of 15.12 m2. Field tests were carried out in on a grassy field with silt-loam soil in Orroli, Sardinia in July and August 2010, and rainfall, soil moisture, and runoff data were collected. The two-term Philip infiltration model was used to find optimal values for the saturated hydraulic conductivity of the soil surface and bulk soil, soil water retention curve slope, and air entry suction head. Optimized hydraulic conductivity values were comparable to both the measured final infiltration rate and literature values for saturated hydraulic conductivity. This inexpensive rainfall simulator can therefore be used to identify field parameters needed for hydrologic modeling.

A Revisit of Rainfall Simulator as a Potential Tool for Hydrological Research

“…But problem with the 80,100-veejet nozzles was that it did not simulate rainfall energy characteristic and is still better than other nozzles. This type of rainfall simulator provides about 80% of the required kinetic energy per volume of natural rain [5,12,13]. This nonzero pressurised nozzle has the following advantages over the hanging yarn simulator [10] as presented by…”

“…(Figure 5). The system was tested with common pressure washing nozzles which produced rainfall intensity of 62.43 mm/h and 32 mm h −1 with a corresponding uniformity coefficient (C.U) of 76.65 and 62% [13]. [23] developed a portable field simulator for use in hillside and obtained a consistent raindrop size of 2.58 mm with an intensities of 20 to 90 mm h −1 and C.U of 91.7% at an intensity of 60 mmh −1 .…”

Rock Water as a Key Resource for Patchy Ecosystems on Shallow Soils: Digging Deep Tree Clumps Subsidize Surrounding Surficial Grass

“…From observed P, the surface runoff Q was estimated using the commonly used Soil Conservation Service (SCS) method (Soil Conservation Service, 1972 and1986;Chow, 1988;Ponce, 1989). We estimated the key parameter of the SCS method, the CN curve number, using the results of the rainfall simulator-based experiments of Wilson et al (2014) for plot-scale runoff simulation, conducted at the site in 2010.…”

Design, Operation and Construction of a Large Rainfall Simulator for the Field Study on Acidic Barren Slope

“…The structure comprises of a square platform of 6 by 6 m, and height of the frame is 2 m, consisting of a framework of steel pipes. Artificial rainfall design in this study quite similar to researcher [18,20] that used a large scale simulator.…”