Characteristics of Splash Erosion and Runoff Under Different Bedrock Fissure Ratios in Karst Slope With Thin Soil Layers

ABSTRACT Splash erosion (SER) is a key stage of soil erosion, and bedrock fissures in the karst area makes the erosion situation complex. However, the effects of different bedrock fissure ratios (BFRs) on SER in karst area have not yet been reported. We investigated the effect of five BFRs (0%, 1%, 2%, 3% and 4%) changes on SER under three slope gradients (10°, 15° and 20°) and one rainfall intensity (1.5 mm min −1 ) in the karst area using simulated rainfall experiments. Single simulated rainfall event lasted for 18 min. The outcomes confirm that as the BFRs increased, the upslope splash erosion (USER), downslope splash erosion (DSER) and total splash erosion (TSER) increased. Surface runoff showed no statistically significant variation across different BFRs and slope gradients, but fissure runoff at 4% BFR was highest for all slopes. BFR was significantly correlated with the fissure runoff, USER, DSER and TSER at 15° and 20° slopes. Our results underscore the greater the BFRs, the greater the SER in karst slope. This work contributes to advancing knowledge about how BFRs impact SER in thin karst soil layers.