Evaluation of an erosion-sediment transport model for a hillslope using laboratory flume data

Abstract

Climate change can escalate rainfall intensity and cause further increase in sediment transport in arid lands which in turn can adversely affect water quality. Hence, there is a strong need to predict the fate of sediments in order to provide measures for sound erosion control and water quality management. The presence of microtopography on hillslopes influences processes of runoff generation and erosion, which should be taken into account to achieve more accurate modelling results. This study presents a physically based mathematical model for erosion and sediment transport coupled to one-dimensional overland flow equations that simulate rainfall-runoff generation on the rill and interrill areas of a bare hillslope. Modelling effort at such a fine resolution considering the flow connection between interrill areas and rills is rarely verified. The developed model was applied on a set of data gathered from an experimental setup where a 650 cm×136 cm erosion flume was pre-formed with a longitudinal rill and interrill having a plane geometry and was equipped with a rainfall simulator that reproduces natural rainfall characteristics. The flume can be given both longitudinal and lateral slope directions. For calibration and validation, the model was applied on the experimental results obtained from the setup of the flume having 5% lateral and 10% longitudinal slope directions under rainfall intensities of 105 and 45 mm/h, respectively. Calibration showed that the model was able to produce good results based on the R 2 (0.84) and NSE (0.80) values. The model performance was further tested through validation which also produced good statistics (R 2 =0.83, NSE=0.72). Results in terms of the sedigraphs, cumulative mass curves and performance statistics suggest that the model can be a useful and an important step towards verifying and improving mathematical models of erosion and sediment transport.

The Wageningen Rainfall Simulator: Set‐up and Calibration of an Indoor Nozzle‐Type Rainfall Simulator for Soil Erosion Studies

“…Laboratory-scale RSs have been used to eliminate some of the disadvantages (for example difficulty with transportation, wet winter soil condition and the concern of growers about cultivation) of the small portable RSs. Laboratory RSs can be used to determine the impact of the soil surface characteristics such as micro-topography, surface roughness and soil chemistry on infiltration, soil aggregate stability, shear stress and erosion rates and to elucidate the processes involved (Meyer, 1965;Bubenzer & Meyer, 1965;Bryan & Shiu-Hung, 1981;Hignett et al, 1995;Bryan, 2000;Esteves et al, 2000;Lascelles et al, 2000;Regmi & Thompson, 2000;Blanquies et al, 2003;Guidry et al, 2006;Birt et al, 2007;Ran et al, 2012;Arguelles et al, 2013Arguelles et al, , 2014. Indoor RSs are also used for scaled experiments, for example, to study the impact of storm movement on overland flow (de Lima & Singh, 2003;de Lima et al, 2009).…”

Empirical Sediment Transport Models Based on Indoor Rainfall Simulator and Erosion Flume Experimental Data

“…Difficulties in the calibration and validation stages of models are other issues to be considered (Aksoy, ). Despite of all these challenges and difficulties, sediment transport models developed at hillslope and watershed scales (Zhang et al, ; Aksoy & Kavvas, ; Arguelles et al, ; Zuliziana et al, ) have enhanced the understanding of the mechanism of sediment transport under varying conditions over the hillslope or watersheds. When the GIS technology is combined with the sediment transport modelling, it is possible to derive an effective way to map spatial distribution of soil erosion risks in large areas to be used in assisting conservation management and land use planning (Mandal & Sharda, ; Dai et al, ).…”

Erosion and Sediment Transport Modeling: A Systematic Review

“…To understand and plan management strategies, it is crucial to have models that can accurately model the effects of changes in agricultural land use, farming practices, and conservation measures [32,33]. In addition to modeling approaches, experimental investigations [34,35] are commonly used to study erosion and sediment transport. Experimental methods involve conducting physical experiments in controlled laboratory settings or in the field to measure erosion rates, sediment yields, and other related parameters [36,37].…”