دورية أكاديمية

Raindrop Size and Flow Depth Control Sediment Sorting in Shallow Flows on Steep Slopes.

التفاصيل البيبلوغرافية
العنوان: Raindrop Size and Flow Depth Control Sediment Sorting in Shallow Flows on Steep Slopes.
المؤلفون: Wang, L., Fang, N. F., Yue, Z. J., Shi, Z. H., Hua, L.
المصدر: Water Resources Research; Dec2018, Vol. 54 Issue 12, p9978-9995, 18p
مصطلحات موضوعية: RAINDROPS, SEDIMENT transport
مستخلص: Raindrop size and flow depth interactions determine the energy available for erosion processes. A detailed laboratory study was conducted to investigate the influence of raindrop size on sediment sorting in shallow flows on steep slopes. Raindrops with sizes of 1.34, 2.45, and 4.04 mm were applied to three inflows (0.65, 1, and 2 L/min) with the same rainfall intensity (90 mm/hr). The De Brouckere mean diameter (D[4,3]) was enhanced with increases in the ratio between flow depth and raindrop size (h/d; p < 0.05), indicating that more raindrop energy dissipated in deeper flows. Moreover, a greater proportion of energy was dissipated from small raindrops than from large ones with an increasing flow depth. Particles >0.5 mm were slightly enriched by rolling under 1.34‐mm raindrop impact, whereas enrichment did not occur under 2.45‐ and 4.04‐mm raindrop impact, probably because the latter induced more severe aggregate disintegration, resulting in fewer coarse particles. The mean sediment concentrations under inflows of 0.65, 1, and 2 L/min were 101.65, 89.32, and 79.02 g/L, respectively. Shallow flows on steep slopes effectively carried detached particles; moreover, coarse particles could roll along the slopes, which was inconsistent with their behavior on gentle slopes. This study highlights the need to understand the influence of the interaction between raindrop size and flow depth on erosion processes associated with sediment size selectivity for better erosion modeling and water quality prediction. Key Points: Sediment size is significantly enhanced as the ratio between flow depth and raindrop size increases on steep slopesA greater proportion of energy is dissipated from small raindrops than from large ones with increasing flow depthCoarse particles are slightly enriched in sediment associated with bed load transport under small raindrop impact [ABSTRACT FROM AUTHOR]
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قاعدة البيانات: Complementary Index
الوصف
تدمد:00431397
DOI:10.1029/2018WR022786