{"title":"Entrainment-driven morphological changes in debris flow deposits by varying water content at laboratory scale","authors":"Nikhil Kumar Pandey, Neelima Satyam","doi":"10.1007/s10064-025-04241-y","DOIUrl":null,"url":null,"abstract":"<div><p>Entrainment is crucial in shaping debris flow deposits, influencing their morphology and dynamics. Understanding deposition driven by entrainment is vital for improving hazard mitigation and sediment management strategies. This study employs a small-scale flume setup to examine the interplay between water content (w/c), sediment composition, and bed morphology on granular flow behavior. Sixteen experiments were conducted, varying w/c (20–50%) and erodible bed configurations, with deposit morphology analyzed for width, thickness, and runout length. The findings revealed distinct patterns in deposit morphology across w/c levels. At lower w/c (20–24%), deposits exhibited broad, shorter lobes with minimal scouring, forming cone-shaped structures. Moderate w/c (~ 28%) enhanced flow mobility, producing thicker deposits near the flume bed due to reduced entrainment. At higher w/c (30–50%), deposits shifted further downstream, driven by greater entrainment volumes and longer runout distances. While higher w/c levels decreased deposit thickness, they significantly widened the runout deposits, demonstrating the dual influence of w/c and entrainment. A clear relationship emerged between entrainment and flow mobility, as increased entrainment volumes widened and flattened deposits. Additionally, water content dominated entrainment in controlling deposit thickness, underscoring its critical role in sediment transport dynamics. The deposits were poorly sorted, with a distinct bedding structure akin to natural debris flows, validating the experimental setup. This study provides an efficient and scalable methodology for analyzing granular flow behavior in erodible beds. The results offer insights into sediment transport processes, bridging the gap between mesoscale experiments and real-world applications in natural hazard mitigation and geotechnical engineering.</p></div>","PeriodicalId":500,"journal":{"name":"Bulletin of Engineering Geology and the Environment","volume":"84 5","pages":""},"PeriodicalIF":3.7000,"publicationDate":"2025-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Bulletin of Engineering Geology and the Environment","FirstCategoryId":"5","ListUrlMain":"https://link.springer.com/article/10.1007/s10064-025-04241-y","RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"ENGINEERING, ENVIRONMENTAL","Score":null,"Total":0}
引用次数: 0
Abstract
Entrainment is crucial in shaping debris flow deposits, influencing their morphology and dynamics. Understanding deposition driven by entrainment is vital for improving hazard mitigation and sediment management strategies. This study employs a small-scale flume setup to examine the interplay between water content (w/c), sediment composition, and bed morphology on granular flow behavior. Sixteen experiments were conducted, varying w/c (20–50%) and erodible bed configurations, with deposit morphology analyzed for width, thickness, and runout length. The findings revealed distinct patterns in deposit morphology across w/c levels. At lower w/c (20–24%), deposits exhibited broad, shorter lobes with minimal scouring, forming cone-shaped structures. Moderate w/c (~ 28%) enhanced flow mobility, producing thicker deposits near the flume bed due to reduced entrainment. At higher w/c (30–50%), deposits shifted further downstream, driven by greater entrainment volumes and longer runout distances. While higher w/c levels decreased deposit thickness, they significantly widened the runout deposits, demonstrating the dual influence of w/c and entrainment. A clear relationship emerged between entrainment and flow mobility, as increased entrainment volumes widened and flattened deposits. Additionally, water content dominated entrainment in controlling deposit thickness, underscoring its critical role in sediment transport dynamics. The deposits were poorly sorted, with a distinct bedding structure akin to natural debris flows, validating the experimental setup. This study provides an efficient and scalable methodology for analyzing granular flow behavior in erodible beds. The results offer insights into sediment transport processes, bridging the gap between mesoscale experiments and real-world applications in natural hazard mitigation and geotechnical engineering.
期刊介绍:
Engineering geology is defined in the statutes of the IAEG as the science devoted to the investigation, study and solution of engineering and environmental problems which may arise as the result of the interaction between geology and the works or activities of man, as well as of the prediction of and development of measures for the prevention or remediation of geological hazards. Engineering geology embraces:
• the applications/implications of the geomorphology, structural geology, and hydrogeological conditions of geological formations;
• the characterisation of the mineralogical, physico-geomechanical, chemical and hydraulic properties of all earth materials involved in construction, resource recovery and environmental change;
• the assessment of the mechanical and hydrological behaviour of soil and rock masses;
• the prediction of changes to the above properties with time;
• the determination of the parameters to be considered in the stability analysis of engineering works and earth masses.