GIS-Remote Sensing Based Approach in Assessing and Modeling Landslide Vulnerability Areas in Southeast Zone of Nigeria

Abstract

The study of landslides is essential in order to avoid hazards occurrence, or at least minimize the adverse effects it has on the environment, properties and human populations whenever it occurs. Identifying vulnerable areas, help in putting up measures to protect or avoid such areas which in a long way reduces the risk associated with the adverse effects of landslide. The study used primary and secondary data that consist of field observation, photographs and other literature from which the likely triggering factors of slope, land use land cover change (LULCC), aspect, soil texture and type, curvature, drainage density, elevation, lineament density, normalized difference vegetation index (NDVI), normalized difference moisture index (NDMI), geology, topographic wetness index (TWI), geomorphology, rainfall, temperature, wind speed, wind pressure, population, river channels and road network construction were extracted. The satellite imageries (SRTM and Landsat 8 OLI-TIRS) data were obtained from USGS Earth Explorer, processed and modeled based on the triggering factors using ArcGIS v10.4, while visits were made to the various parts of the study area for validation and confirmation of results. Microsoft Excel 2007 was used to compute and assign weights to the triggering factors; experts’ knowledge was sought in regrouping the factors, while weighted overlay methods in the spatial analyst tool of ArcGIS v10.4 were applied to generate the model of landslide vulnerable areas in the study area. The study recommended among other things creating a regional body vested with powers and resources to effectively monitor the environment, providing alternative means of livelihood that will discourage mining, deforestation, forest fire, and overgrazing, and encourage sustainable resource use and management that will not expose the areas to the triggering factors of landslide.