Friday, November 11, 2011

ASTER Imagery and its Application to Landslide Susceptibility Mapping

A research by Hyun-Joo Oh, No-Wook Park, Sung-Soon Lee & Saro, published recently in the International Journal of Remote Sensing, extracted landslide-related factors from remote-sensing data, such as Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) satellite imagery, and examined their applicability to landslide susceptibility near Boun, Korea, using a geographic information system (GIS).

Landslide occurrence locations in the Boun area identified from aerial photograph interpretation and field surveying were formed into a GIS database. Various influencing factors were extracted from ASTER imagery. These were aspect, slope, curvature, lineament proximity and land-cover. The relationship of slide events and associated factors was analysed for landslide susceptibility assessment using the probability–frequency ratio and statistics-logistic regression models. The ratio and coefficient from the relationship was then summed up to calculate an LSI, and from this a susceptibility map was made and verified by calculating the correlation observed between occurrence locations and the results. In verification, the frequency ratio model showed 84.78% accuracy and the logistic regression model showed 84.20% accuracy. This suggests that the accuracy of the resultant landslide susceptibility map using the ASTER DEM is reasonably good with observed accuracy measured to 25.77 m RMSE for the studied area. The ASTER imagery can therefore be used in landslide susceptibility mapping. In particular, the frequency ratio model can be quickly and easily applied to the areas with little available map data, with a very low cost. Using the ASTER DEM, frequency ratio and logistic regression models need further testing for landslide susceptibility accuracy based on the RMSE of ASTER DEM studies in the various physiographic areas.

There are many high-resolution satellite images currently available, and these can be used to detect the locations of landslides. Although aerial photographs were used here for detecting landslide, the 15 m resolution ASTER images could be used for that, and considering the frequency of ASTER imagery allows a comparison to be made before and after an event. An image resolution of 15 m can distinguish large-scale landslides, and this could be improved by the 1 m resolution images now commercially available.

Landslide susceptibility maps are of great help to planners and engineers in their choosing of areas for further detail survey and of locations suitable for development. Our results provide basic data to assist slope management and land use planning in the Boun area. The methods used in the study are valid for generalized planning and assessment purposes, although they may be less useful at the site-specific scale where local geological and geographic heterogeneities may prevail. For the models to be more generally applied, more landslide data are needed and more case studies conducted.

Read more from the source:
Hyun-Joo Oha, No-Wook Parkb, Sung-Soon Leec & Saro. 2011. Extraction of landslide-related factors from ASTER imagery and its application to landslide susceptibility mapping, International Journal of Remote Sensing, Volume 33, Issue 10. DOI:10.1080/01431161.2010.545084

The research was supported by the Basic Research Project of the Korea Institute of Geoscience and Mineral Resources (KIGAM) funded by the Ministry of Science and Technology of Korea.


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