Spatial analysis approaches for the characterisation and monitoring of slope instability and deformation

• Main Author: Bell, Andrew D. F.
• Published: Queen's University Belfast 2014
• Subjects: 551.3
• Online Access: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.676269

This thesis focuses on the use of Terrestrial LiDAR Scanning (TLS) for the monitoring of active slopes. Research into this area has developed an innovative methodological framework of spatial analysis approaches for the characterisation and monitoring of active slope instability sites. Methods implemented include monitoring using TLS derived Digital Terrain Models (DTMs) with scans conducted approximately every two months. Temporal responses of morphological parameters to slope instability and deformation were assessed. A pioneering assessment of TLS deviations over a scanning period of one day was utilised to identify the implications systematic errors have for temporal monitoring analysis. An evaluation of standard and robust statistics, statistics which are not affected by outliers, is presented for the applicability of TLS with implications for terrain evolution and error assessment. In addition to TLS monitoring, Aerial LiDAR (ALS) was assessed for the application of the morphological characterisation on a larger scale from selected sites around the world including the United Kingdom (UK) and Canada. This thesis presents the temporal, statistical and morphological responses of slope deformation over a monitoring period of two years. Rates of movement were found to vary with greatest magnitude occurring during Winter and Spring. Evaluation of error over the one day period identified limited deviation in the acquisition of successive point clouds. The implications for this error assessment illustrated the potential use of robust statistical measures. Temporal morphological assessment resulted in the identification of pre-and post-failure characterisation of slope instability. This resulted in the development of a quasi-empirical model of failure for the selected slopes. Spatial analysis results were validated using Aerial LiDAR and TLS datasets. The overarching impact of this thesis is that it has provided insight into the real world application of TLS monitoring of slope deformation and the benefits of such investigation for partner organisations and their key remits to governmental bodies.