Effects of the angle between the rock strata and slope on flow hydraulics and sediment yield in karst trough valley: Laboratory scour experiment  

作　　者：Yuqi Zhang Lan Song Yunfei Bi Binghui He Rongchang Zeng Tianyang Li 

机构地区：[1]College of Resources and Environment,Southwest University,Chongqing 400715,China [2]Key Laboratory of River and Lake Regulation and Flood Control in the Middle and Lower Reaches,Ministry of Water Resource,People's Republic of China,Yangtze River Scientific Research Institute,Wuhan 430010,China

出　　处：《International Journal of Sediment Research》2024年第1期100-109,共10页国际泥沙研究（英文版）

基　　金：the National Key R&D Program of China(Grant No.2022YFF1302903);the CRSRI Open Research Program(Grant No.CKWV20221005/KY);the Innovation Research 2035 Pilot PlanofSouthwest University(Grant No.SWUXDZD22003);the Fundamental Research Funds for the Central Universities(Grant No.SWU-KT22060);the Natural Science Foundation of Chongqing,China(Grant No.CSTB2022NSCQ-MSX0385);the State Cultivation Base of Eco-agriculture for Southwest Mountainous Land,Southwest University.

摘　　要：The angle between the exposed bedrock and slope in a karst trough valley strongly affects overland flow behavior,thus,altering the generation of runoff and sediment.However,the directions and magnitudes of these effects remain unclear.The current study aimed to investigate the effects of the angle between the rock and slope on flow hydraulics,runoff,and sediment yield,as well as their linkages.A laboratory flume scour experiment was done under different combinations of angles between rock strata and slope(0,30°,60°,90°,120°,and 150°),flow discharge rates(5,7.5,and 10 L/min)and slope gradients(10°,15,and 20°)to simulate the field environment in a karst trough valley.The flow hydraulics(Reynolds number,flow velocity,flow depth,and Darcy-Weisbach friction factor),sediment yield,sediment con-centration,and runoff rate were determined.The results showed that with increasing scour duration,the Reynolds number and flow velocity decreased but the flow depth and Darcy-Weisbach friction factor increased.The angle between the rock strata and slope significantly affected the flow velocity and Darcy-Weisbach friction factor,while slightly affecting the flow depth and Reynolds number.Over the scour duration,the runoff rate first increased and remained at a steady state but the sediment concentration and sediment yield rate first increased and then sharply decreased to a steady state.The sediment concentration and sediment yield rate both significantly decreased as the angle between the rock strata and slope increased.The runoff rate was closely linked to the flow velocity and Darcy-Weisbach friction factor as well as the sediment yield rate and sediment concentration.The current results indicate that the angle between the rock strata and the slope should be considered an important parameter when developing a soil erosion prediction model for karst trough valleys.

关 键 词：RUNOFF Soil erosion Exposure bedrock Prediction model KARST 

分 类 号：S157.1[农业科学—土壤学]