Modeling on management strategies of slope stability and susceptibility to landslides catastrophe at hilly region in Bangladesh

Abstract

The hilly terrain in the southeastern part of Bangladesh particularly Khulshi Thana at Chittagong City has the long history of slope instability. The present study, therefore, tried to analyze the slope stability of vulnerable slope using Scheidegger 1970 slope stability method. Moreover, the purpose of the exploration is to find out causes of slope instability, analysis of slope stability intensity and predicting mapping through GIS techniques. Slope stability data are collected from the study area by measuring slope of angle, height and soil texture density. The average height, slope of angle and soil texture density represent 11.26 m, 74.82° and 1.67 g/cm3, respectively. The weight (W) of the sliding per unit width, 307.01, The component W parallel to the slide surface, The component W that normal the slide surface represent 307.01, 288.6 and, respectively. The average critical height (hcr) at which the bank of slope become unstable is 17.63. On the basis of physical environment (geological formation and geomorphological unit, aspects, slope of angle, elevation, soil texture density) the spatial distribution of slope stability parameter intensity are mapping and these helps policy makings, proper urban planning and decision building. This research recommends that along with permanent structure, informal settlements also relocate from the susceptible unstable slope to reduce the vulnerability of landslides hazard. Moreover, under no circumstance the top hills of these areas should not be fixed by concrete structure, so that these hilly areas can operate their own natural geological and geomorphological readjustments. Ensure the protection of existing hills and sounding ecology from the all types of illegal hill cutting. Study comprises development of spatial slope stability intensity zoning map of Khulshi Thana which helps policy makers, engineers, town planners and geologist to build up a rationally geological hazard free safe hilly city.