Sediment Transport Model for a Surface Irrigation System

Damodhara R. Mailapalli,Rajendra Singh,Narendra S. Raghuwanshi

doi:10.1155/2013/957956

Abstract

Controlling irrigation-induced soil erosion is one of the important issues of irrigation management and surface water impairment. Irrigation models are useful in managing the irrigation and the associated ill effects on agricultural environment. In this paper, a physically based surface irrigation model was developed to predict sediment transport in irrigated furrows by integrating an irrigation hydraulic model with a quasi-steady state sediment transport model to predict sediment load in furrow irrigation. The irrigation hydraulic model simulates flow in a furrow irrigation system using the analytically solved zero-inertial overland flow equations and 1D-Green-Ampt, 2D-Fok, and Kostiakov-Lewis infiltration equations. Performance of the sediment transport model was evaluated for bare and cropped furrow fields. The results indicated that the sediment transport model can predict the initial sediment rate adequately, but the simulated sediment rate was less accurate for the later part of the irrigation event. Sensitivity analysis of the parameters of the sediment module showed that the soil erodibility coefficient was the most influential parameter for determining sediment load in furrow irrigation. The developed modeling tool can be used as a water management tool for mitigating sediment loss from the surface irrigated fields.

Highlights

Surface irrigation is a widely used farming system for crop production as it requires less skilled labour and involves less operational cost
The following sections describe the estimation of tractive force or hydraulic shear (τ), critical shear, soil erodibility coefficient (Kr) and transport capacity (Tc), which are essential for estimation of sediment load. (a) Tractive Force (τ)
The visual observation of the trends between observed and simulated sediment loads by 2D-Fok, 1DGreen Ampt, and KL infiltration equations depicted that the sediment load predictions were not good with the baseline values of τc and Kr

Summary

Introduction

Surface irrigation is a widely used farming system for crop production as it requires less skilled labour and involves less operational cost. Mailapalli et al [6] estimated as 0.4 Mg ha−1 of soil loss for bare and 0.2 Mg ha−1 for cropped furrow fields in an irrigation event. Strelkoff et al [19] developed SRFR for simulating flow, soil erosion, and deposition at various points along the furrow using Laursen [22], Yang [23], and Yalin [24] sediment transport equations. The hydraulic component of furrow irrigation can be accurately modeled using the irrigation model presented by Mailapalli et al [26] They used analytical solution of zeroinertia equations for simulating overland flow and multiple infiltration models such as 2D-Fok [27], 1D-Green Ampt [28] and Kostiakov-Lewis [29] for estimating infiltration. We attempted to integrate a quasi-steady state sediment transport model described by Trout and Neibling [30] to the hydraulic component of Mailapalli et al [26] irrigation model and evaluated performance of model integration for estimating irrigation-induced erosion

Theoretical Considerations

Model Evaluation

Results and Discussion

Conclusions