Quantitative expression method of erosion sediment transport capacity of shallow trench

Abstract

The invention relates to a quantitative expression method of erosion sediment transport capacity of shallow trench. The method comprises the following steps: S1, measuring a sediment content corresponding to the shallow trench along with different trench lengths under different hydrodynamic conditions, and obtaining a corresponding relationship between the erosion sediment concentration of the shallow trench and the trench lengths; S2, according to the corresponding relationship between the erosion sediment concentration of the shallow trench and the trench lengths obtained in S1, calculatinga sediment transport amount per unit time of water flow of the shallow trench erosion under different hydrodynamic conditions; S3, according to the data in S2, obtaining a composite nonlinear mathematical relationship of the sediment transport amount per unit time of the water flow with the change of trench lengths under different hydrodynamic conditions; and S4, calculating the sediment transportcapacity according to the composite nonlinear mathematical relationship of the sediment transport capacity with the change of the trench lengths in S3. According to the quantitative expression methodof the erosion sediment transport capacity of the shallow trench, the erosion sediment transport capacity of the shallow trench under any hydrodynamic condition can be calculated only by establishinga response relationship between the sediment transport capacity of the shallow trench and a slope length.

Description

Technical field [0001] The invention relates to the fields of soil erosion and water and soil conservation, and farmland non-point source pollution control, and in particular to a system and method for determining the sand transport capacity of shallow trench erosion. Background technique [0002] Shallow gullies are the main source of erosion and sediment yield on slopes and sediment transport channels. The slopes with shallow gullies quickly collect runoff during the rainfall process, forming a stream with strong erosion force, and the erosion kinetic energy increases sharply, becoming cut-off erosion and gully head. The source of power for advancement has caused great damage to land resources. Due to the significant contribution of shallow gully erosion to the total erosion and sediment transport on slopes, it has aroused great interest in shallow gully erosion simulation and prediction research at home and abroad in the past ten years. At present, there are WEPP (Water Erosi...

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Problems solved by technology

At present, there is WEPP (Water Erosion Prediction Project) as a model that can simulate the erosion process of shallow gullies. However, due to the limitations of test methods and calculation methods, the sediment transport capacity in the sediment yield equation cannot be directly measured and calculated through experiments, which limits the use of the model in shallow trenches. Application in Gully Erosion Forecast

The developed shallow gully erosion model EGEM (Ephemeral Gully Erosion Model) can be used to predict the average annual erosion of shallow gully, but it cannot reflect the spatiotemporal change process of shallow gully erosion and sediment yield, and can only predict soil erosion information in limited space and time points

Due to the lack of a reasonable parameter calculation method, when there is a difference between the simulated value and the measured value, it is difficult to distinguish whether the error comes from the model itself or the wrong parameter selection

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