Abstract:
Forecasting the potential for disastrous events such as landslides has become one of the
major necessities in the current world. Most of the landslides occurring in Sri Lanka are found to be
triggered by intense rainfall events. This study was carried out on a landslide that occurred near
Gerandiella waterfall, located in Kotmale Divisional secretariat in Sri Lanka. This project investigates
the possibility of developing a dynamic model to map the spatial distribution of the slope stability
using Geographic Information System (GIS). The model incorporates several theoretical models
including the infinite slope model, Green Ampt infiltration model and Perched ground water flow
model. A series of rainfall values can be fed to the model as the main input to simulate the dynamics
of slope stability. Hydrological model developed using GIS is used to quantify the perched water table
height. Infinite slope stability model is used to quantify the degree of slope stability in terms of factor
of safety. DEM was built with the use of digitized contour data. Stratigraphy was modelled in Surfer
software using borehole data and resistivity images. This model equipped with the predicted rainfall
values can be used to forecast the slope dynamics of the area of interest.
Citation:
Abeygunasekara, W.A.H.A., Hewavidana, S.M., Jananthan, T., Madawala, R.M.S., Vaheeshan, K., Premasiri, H.M.R., Abeysinghe, A.M.K.B., & Weerawarnakula, S. (2014). Dynamic model to forecast slope stability - a case study: Geradiella lanslide site. In P.V.A. Hemalal (Ed.), Proceedings of the 8th National Conference on Earth Resources Management (pp. 43-48). Department of Earth Resources Engineering, University of Moratuwa.