Premium
The hydrodynamic mechanism of rainfall runoff from loess slopes treated with incorporated straw
Author(s) -
Liu Huaqing,
Yang Jiahui,
Diao Yanfang,
Lei Tingwu,
Rahma Abbas E.
Publication year - 2021
Publication title -
land degradation and development
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.403
H-Index - 81
eISSN - 1099-145X
pISSN - 1085-3278
DOI - 10.1002/ldr.3941
Subject(s) - froude number , surface runoff , loess , straw , soil science , diffusion , hydrology (agriculture) , dispersion (optics) , water erosion , environmental science , flow (mathematics) , soil water , geology , chemistry , geotechnical engineering , geomorphology , mathematics , geometry , physics , inorganic chemistry , ecology , biology , thermodynamics , optics
The hydrodynamic parameters of rainfall runoff are important for those studying hillslope water flow, which in turn affects soil erosion, chemical pollutant migration, and diffusion. Straw incorporation into the cultivated soil layer may affect soil properties, resulting in different hydrodynamic behaviours of hillslope runoff. The objective of this study was to evaluate the influences of straw incorporation, rainfall intensity, and slope gradient on hydraulic parameters, such as the Reynolds number ( Re ), Froude number ( Fr ), Darcy‐Weisbach friction factor ( f ), and hydrodynamic dispersion coefficient ( D H ). Laboratory experiments were conducted under four straw incorporation rates (SRs: 0, 2, 4, and 8 t ha −1 ), three rainfall intensities (RIs: 80, 120, and 160 mm hr −1 ), and three slope gradients (SGs: 10, 15, and 20°) to examine the hydrodynamic characteristics. The results show that the increase in SR significantly reduces the D H . Compared with bare soil slope (0.020 m 2 s −1 ), the mean D H decreased by half (0.011 m 2 s −1 ) at an SR of 2 t ha −1 and approximately three‐quarters (0.005 m 2 s −1 ) at an SR of 8 t ha −1 . Both Re and Fr decreased with a rise in the SR; however, the slope roughness increased, which caused a significant increase in frictional force compared to results observed for the bare soil. A rise in RI and SG increased the driving force on the farmland slope. The Re and Fr decreased with RI and SR, while f increased with RI and SG. Therefore, this study elucidates that the incorporation of straw in the soil can alter the hydrodynamic parameters, thus influencing water flow velocity and soil erosion.