Three Dimensional Visualisation of Landslides in SE Spain using a Digital Elevation Model (DEM) and Orthophotography

This paper demonstrates how digital elevation models (DEM) can be used with orthophotographs to produce three dimensional views of landslides near Sorbas, Almeria Province, S.E. Spain. ERDAS OrthoMAX software was used to generate DEMs from conjugate relationships of 60% overlap stereo aerial photography. The DEMs were then used to orthorectify the photographs to produce terrain corrected image maps.

Three dimensional viewing of the orthophotographs using the DEM allows improved interpretation of the landslides and shows the relationship between land-cover (rock types, soil and vegetation) and terrain. Edge enhancement techniques were applied to the DEM to accentuate the landslide morphology, using textural information. The results show that a DEM provides additional information about geomorphology beyond that available from two dimensional imagery alone.

Virtual mapping of the landslides can be used to identify specific localities for detailed field measurements. This enhanced geo-morphological information integrated with imagery and geotechnical data in a GIS, can contribute significantly to the landslide hazard (and other geohazard) analysis.

• INTRODUCTION

• DEM GENERATION

• IMAGE PROCESSING

• SLOPE STABILITY APPLICATIONS

• DISCUSSION & CONCLUSIONS

• ACKNOWLEDGEMENTS

• REFERENCES