Effects of patterned Artemisia capillaris on overland flow resistance under varied rainfall intensities in the Loess Plateau of China

In this paper simulated rainfall experiments in laboratory were conducted to quantify the effects oƒ patchy distributed Artemisia capillaris on spatial and temporal variations oƒ the Darcy-Weisbach friction coefficient (f). Different intensities oƒ 60, 90, 120, and 150 mm h-1 were applied on a bare plot (CK) and four different patched patterns: a checkerboard pattern (CP), a banded pattern perpendicular to slope direction (BP), a single long strip parallel to slope direction (LP), and a pattern with small patches distributed like the letter ‘X’ (XP). Each plot underwent two sets oƒ experiments, intact plant and root plots (the above-ground parts were removed). Results showed that mean ƒ for A. capillaris patterned treatments was 1.25-13.0 times oƒ that for CK. BP, CP, and XP performed more effectively than LP in increasing hydraulic roughness. The removal oƒ grass shoots significantly reduced f. A negative relationship was found between mean ƒ for the bare plot and rainfall intensity, whereas for grass patterned plots fr (mean ƒ in patterned plots divided by that for CK) increased exponentially with rainfall intensity. The ƒ -Re relation was best fitted by a power function. Soil erosion rate can be well described using ƒ by a power-law relationship