RAINFALL-RUNOFF EXPERIMENT USING INSTRUMENTED FLUME FOR LANDSLIDES

Abstract

Rainfall-triggered landslides pose significant threats worldwide, necessitating a comprehensive understanding of rainfall-runoff processes, sediment transport, and deposition. This laboratory based study investigates these processes using instrumented flumes. The study focuses on the effects of rainfall intensity, slope angle, soil type, and sediment deposition on flow characteristics and sediment transport. Through experimental simulations of rainfall-runoff events, flow parameters, sediment concentration, and moisture content are measured using instrumented flumes and a moisture sensor. The results provide insights into water movement, soil moisture dynamics, sediment behaviour, and the role of sediment deposition in landslide development. This research contributes to improved landslide management and mitigation strategies by enhancing the understanding of rainfall-runoff processes and sediment transport, and by incorporating the accurate assessment of soil moisture using a moisture sensor in the methodology. The findings demonstrate the utility of instrumented flumes and moisture sensors for investigating rainfall-runoff-landslide interactions and inform the development of effective hazard assessment and mitigation strategies. By performing flume experiment on two different types of soil (one was fine soil and second was sandy soil), it is observed that the runoff generation depends on rainfall intensity as well as the hydraulic conductivity of soil. If the hydraulic conductivity of soil is greater than rainfall intensity, the infiltration and subsequently subsurface discharge will occur, whereas if rainfall intensity is greater than hydraulic conductivity of soil then more runoff generation and surface discharge will occur. Overall, this study advances the scientific knowledge in the field and offers valuable insights for addressing the challenges posed by rainfall-triggered landslides.