Impact of tillage erosion on water erosion in a hilly landscape
| Autor: | Jianhui Zhang, Litao Jia, Zilai Zhang, Y. Wang |
|---|---|
| Rok vydání: | 2016 |
| Předmět: |
Hydrology
Environmental Engineering 010504 meteorology & atmospheric sciences Sediment 04 agricultural and veterinary sciences 01 natural sciences Pollution Tillage Flux (metallurgy) Critical resolved shear stress 040103 agronomy & agriculture Shear stress Erosion 0401 agriculture forestry and fisheries Environmental Chemistry Environmental science Surface runoff Waste Management and Disposal Intensity (heat transfer) 0105 earth and related environmental sciences |
| Zdroj: | Science of The Total Environment. :522-532 |
| ISSN: | 0048-9697 |
| DOI: | 10.1016/j.scitotenv.2016.02.045 |
| Popis: | Little has been known of the interaction between tillage erosion and water erosion, while the two erosion processes was independently studied. Can tillage-induced soil redistribution lead to exaggerated (or retarded) runoff flow and sediment concentrations in steeply sloping fields? A series of simulated tillage and artificial rainfall events were applied to rectangular runoff plots (2 m x 8 m) with a slope of 15 degrees to examine the impacts of tillage erosion intensities on water erosion in the Yangtze Three Gorges Reservoir Area, China. Mean flowvelocity, effective/critical shear stress, and soil erodibility factor K were calculated to analyze the differences in hydrodynamic characteristics induced by tillage. Our experimental results suggest that mean runoff rates were 2.26, 1.19, and 0.65 L min(-1) and that mean soil detachment rates were 1.53, 1.01, and 0.61 g m(-2) min(-1) during the 70-min simulated rainfall events for 52-, 31-, and 10-year tillage, respectively. A significant difference (P < 0.05) in cumulative detachment amounts was found among different tillage intensities. Compared with the soil flux of 0 kg m(-1), cumulative detachment amounts for the soil fluxes of 9.86 and 24.72 kg m(-1) increased by 40.02% and 100.94%, respectively, during the 30-min rainfall event. The results imply that soil and water losses tended to increase with increasing tillage intensity. A significant difference in mean flow velocity occurred near the upper and lower slope boundaries of the field, while significant differences (P < 0.05) in runoff depth and effective shear stress were observed among different slope positions. Soil erodibility factor K for the soil fluxes of 9.86 and 24.72 kg m(-1) were 2.40 and 5.11 times higher, respectively, than that for the soil flux of 0 kg m(-1). As tillage intensity increased, critical shear stress trended to gradually decrease for all soil fluxes. Our results indicate that tillage erosion increases soil erodibility and delivers the soil for water erosion in sloping fields, accelerating water erosion. (C) 2016 Elsevier B.V. All rights reserved. |
| Databáze: | OpenAIRE |
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