Landslide imaging techniques for urban geoscience reconnaissance

Engineering geologists now have at their disposal a wide variety of imaging techniques and technologies available for rapid terrain evaluation and assessment. These techniques include the use of remotely sensed data sets, traditional aerial photography, geophysical imaging, terrestrial laser scanning (LiDAR) and derived digital terrain models (DTM). This paper will describe the use of these techniques for a road corridor hazard assessment for a road by-pass scheme in the Jurassic strata of the Cotswolds, UK. The proposed road route would pass through an extremely problematic terrain that was prone to landsliding and general slope instability. Many active and relict slope features were present in the area including shallow rotational slides to more deep-seated features within the strata. Solifluction features were also present with many relict shear surfaces present. The reactivation or disturbance of these features would potentially have a severe impact on both the proposed construction project and to the urban environment in the immediate vicinity. The paper will critically review the techniques used and will describe in detail the use of remotely sensed Airborne Thematic Mapper scenes (ATM), aerial photography and the use or LiDAR data for the hazard assessment.