Hydrological Modelling to Estimate Runoff and Infiltration in Southeastern Appalachian Debris Flow Complex
Mandal A and Nandi A. 2017. Hydrological Modelling to Estimate Runoff and Infiltration in Southeastern Appalachian Debris Flow Complex. Pages 502-513. In Mandal A and Nandi A (ed): 3rd North American Symposium on Landslides. Roanoke, VA. June 4-8, 2017. Association of Environmental & Engineering Geologists (AEG)
ABSTRACT: Debris flows are frequent events in the Southeastern Appalachians, United States, initiated in highly weathered, fractured metasedimentary rocks, primarily triggered by spring and summer thunderstorms. Field observations and previous studies suggested that favorable saprolite overburden, bedrock, geologic structures, and most importantly, the subsurface hydrologic processes play vital roles in debris flow initiation and pathways. In the present study hydrological modelling of the West Prong Little Pigeon River (WPLPR) watershed of the Great Smoky Mountain National Park is performed with special emphasis on the north-eastern, eastern and southern catchments with maximum occurrences of debris flow. This is an ideal watershed to study rainfall-runoff effects, as the extreme rainfall events often produce debris flows in the area. Rainfall-runoff modelling using the HEC HMS hydrological modelling system was conducted to obtain peak runoff and discharge hydrographs from rainfall, infiltration capacity of the bedrock and saprolite in debris flow initiation zones. The simulation for peak discharge was estimated for three different peak rainfall events of the year, 2012 (July, August and September) when significant debris flows were documented. The Curve Number method was used to compute runoff from rainfall using LiDAR (Light Detection And Ranging) based digital elevation model, hydrologic soil group, landcover and rainfall as input parameters. Both monthly rainfall-runoff and runoff simulation from the max. 24 hr rainfall for the months of July, August and September (wet months) were carried out using HEC HMS to estimate potential peak discharge, infiltration and total volume of runoff for each month.
- Type
- Conference Proceeding Paper
- Authors
- Mandal, Arpita; Nandi, Arpita
- Units
- GRSM
- Keywords
- Alum Cave Trail, APHN, Appalachian Highlands Network, discharge, Great Smoky Mountains National Park, GRSM, GRSM-01169, infiltration, landslides, modeling, Mt. LeConte, rainfall, runoff, SER, Southeast Region, West Prong Little Pigeon River