Debris-Slide Susceptibility Modelling Using GIS Technology in the Great Smoky Mountains National Park

Debris-slides are one of the most frequently occurring geological hazards in metasedimentary rocks of the Anakeesta ridge in Great Smoky Mountains National Park (GRSM), which often depends on the influence of multiple causing factors or geo-factors such as geological structures, slope, topographic elevation, land use, soil type etc. or a combination of these factors. The main objective of the study was to understand the control of geo-factors in initiating debris-slides using different knowledge and data-driven methods in GIS platform. The study was performed in three steps: (1) Evaluation of geometrical relationship between geological discontinuity and topographic orientation in initiation of debris-slides, (2) Preparation of knowledge-driven debris-slide susceptibility model, and (3) Preparation of data-driven debris-slide susceptibility models and compare their efficacy. Performance of the models were evaluated mostly using area under Receiver Operating Characteristic (ROC) curve, which revealed that the models were statistically significant

An evidential reasoning geospatial approach to transport corridor susceptibility zonation

PhD ThesisGiven the increased hazards faced by transport corridors such as climate induced extreme weather, it is essential that local spatial hot-spots of potential landslide susceptibility can be recognised. Traditionally, geotechnical survey and monitoring approaches have been used to recognise spatially landslide susceptibility zones. The increased availability of affordable very high resolution remotely-sensed datasets, such as airborne laser scanning (ALS) and multispectral aerial imagery, along with improved geospatial digital map data-sets, potentially allows the automated recognition of vulnerable earthwork slopes. However, the challenge remains to develop the analytical framework that allows such data to be integrated in an objective manner to recognise slopes potentially susceptible to failure. In this research, an evidential reasoning multi-source geospatial integration approach for the broad-scale recognition and prediction of landslide susceptibility in transport corridors has been developed. Airborne laser scanning and Ordnance Survey DTM data is used to derive slope stability parameters (slope gradient, aspect, terrain wetness index (TWI), stream power index (SPI) and curvature), while Compact Airborne Spectrographic Imager (CASI) imagery, and existing national scale digital map data-sets are used to characterise the spatial variability of land cover, land use and soil type. A novel approach to characterisation of soil moisture distribution within transport corridors is developed that incorporates the effects of the catchment contribution to local zones of moisture concentration in earthworks. In this approach, the land cover and soil type of the wider catchment are used to estimate the spatial contribution of precipitation contributing to surface runoff, which in turn is used to parameterise a weighted terrain accumulation flow model. The derived topographic and land use properties of the transport corridor are integrated within the evidential reasoning approach to characterise numeric measures of belief, disbelief and uncertainty regarding slope instability spatially within the transport corridor. Evidential reasoning was employed as it offers the ability to derive an objective weighting of the relative importance of each derived property to the final estimation of landslide susceptibility, whilst allowing the uncertainty of the properties to be taken into account. The developed framework was applied to railway transport earthworks located near Haltwhistle in northern England, UK. This section of the Carlisle-Newcastle rail line has a ii history of instability with the occurrence of numerous minor landslides in recent years. Results on spatial distribution of soil moisture indicate considerable contribution of the surrounding wider catchment topography to the localised zones of moisture accumulation. The degrees of belief and disbelief indicated the importance of slope with gradients between 250 to 350 and concave curvature. Permeable soils with variable intercalations accounted for over 80% of slope instability with 5.1% of the earthwork cuttings identified as relatively unstable in contrast to 47.5% for the earthwork embankment. The developed approach was found to have a goodness of fit of 88.5% with respect to the failed slopes used to parametrise the evidential reasoning model and an overall predictive capability of 77.75% based on independent validation dataset.TETFUND Nigeria, Nasarawa State University and my family members for their financial support towards the completion of the PhD programme

Development of a data-driven model for spatial and temporal shallow landslide probability of occurrence at catchment scale

Open access funding provided by Universita degli Studi di Pavia within the CRUI-CARE Agreement. This work has been in the frame of the ANDROMEDA project, which has been supported by Fondazione Cariplo, grant no. 2017-0677.We thank the anonymous reviewers for their contributions in improving the paper. We thank Beatrice Corradini for the help in the collection of rainfall data and of shallow landslide events.A combined method was developed to forecast the spatial and the temporal probability of occurrence of rainfall-induced shallow landslides over large areas. The method also allowed to estimate the dynamic change of this probability during a rainfall event. The model, developed through a data-driven approach basing on Multivariate Adaptive Regression Splines technique, was based on a joint probability between the spatial probability of occurrence (susceptibility) and the temporal one. The former was estimated on the basis of geological, geomorphological, and hydrological predictors. The latter was assessed considering short-term cumulative rainfall, antecedent rainfall, soil hydrological conditions, expressed as soil saturation degree, and bedrock geology. The predictive capability of the methodology was tested for past triggering events of shallow landslides occurred in representative catchments of Oltrepò Pavese, in northern Italian Apennines. The method provided excellently to outstanding performance for both the really unstable hillslopes (area under ROC curve until 0.92, true positives until 98.8%, true negatives higher than 80%) and the identification of the triggering time (area under ROC curve of 0.98, true positives of 96.2%, true negatives of 94.6%). The developed methodology allowed us to obtain feasible results using satellite-based rainfall products and data acquired by field rain gauges. Advantages and weak points of the method, in comparison also with traditional approaches for the forecast of shallow landslides, were also provided.Universita degli Studi di Pavia within the CRUI-CARE AgreementFondazione Cariplo 2017-067

Geographical information systems (GIS) applied to landslide hazard mapping and evaluation in north-east Wales

Slope instability is a significant environmental hazard in North-East Wales, responsible for important damage to roads and built-up areas. During the late 1980s and the 1990s, systematic landslide mapping and hazard modelling was completed for a number of landslide prone areas within Great Britain, but no such study has to date been carried out for North Wales. This thesis reports on the creation of a digital landslide inventory for North-East Wales and the use of a Geographical Information System (GIS) to create the first landslide susceptibility models for the area. The research has resulted in the most comprehensive landslide inventory of NorthEast Wales completed to date. This was accomplished through a combination of aerial photograph interpretation, field mapping and data collection from secondary sources (e.g. consultancy reports, newspapers), yielding a database that records 430 landslides for the area. This represents a 76% (186 landslides) increase on the number of landslides recorded for the area in the UK national landslides database. The landslides in North-East Wales are almost entirely situated inland, with less than 1% on the coast. Approximately 84% of the landslides occur ~ithin drift geology and 16% in solid geology. For the slides of known type, 46% are translational slides, 47% rotational slides, 3% flows, 3% falls and 1% complex failures. The type and distribution of landsliding in the area shows notable differences to that found in areas of similar bedrock geology elsewhere in the UK (e.g. Derbyshire and South Wales). Analysis shows that the main landslide controlling parameters in North-East Wales are: lithology, drift material, slope angle, proximity to known faults (structural weaknesses) and proximity to fluvial channels (undercutting). These factors were weighted statistically based on their estimated contribution to slope instability, and combined to create the landslide susceptibility models using a statistical (multiple logistic regression) approach. The resulting models divide the landscape of NorthEast Wales into areas of 'low', 'moderate' and 'high' landslide susceptibility using calculated probability values. These models indicate that 8% of the surface exposure of drift deposits and 12% of the area of solid geology are classified as being of high or very high susceptibility to slope instability. Validation of the models indicates that they have success rates of up to 80% in predicting the location of known (documented and mapped) landslides. This compares very favourably to models produced elsewhere. The usefulness of the models as a landslide management tool has also been explored by carrying out a landslide impact survey for built-up areas of Holywell and Greenfield Valley in the north of the study area, where there are a number of well defined ('known') landslides. The landslide impact survey highlights that damage to the built environment extends beyond these known landslides into areas indicated by the models as being of high and very high susceptibility to slope instability. This emphasises the value of GIS techniques, incorporating direct and indirect landslide mapping, in landslide susceptibility modelling and associated landslide management

Räumliche Analyse und Gefährdungsmodellierung von Rutschungen in der rhenodanubischen Flyschzone (NÖ)

Diese Arbeit zeigt die wichtigsten rutschungsfördernden Faktoren der rhenodanubischen Flyschzone von Niederösterreich auf und stellt die gefährdeten Bereiche anhand von Gefahrenhinweiskarten räumlich differenziert dar. Durch Verwendung von zwei Modellierungsansätzen (logistische Regression und Landslide Susceptibility Index) und zwei unabhängig voneinander erstellten Rutschungsinventaren wird sowohl der Einfluss der Methode als auch der zugrundeliegenden Inventare dargestellt. Trotz der hohen statistischen Gütemaße belegen die Ergebnisse Limitationen einer rein quantitativen Herangehensweise sowie eine hohe Abhängigkeit von der zugrundeliegenden Datenbasis. Eine generierte Gefahrenhinweiskarte weist sowohl eine hohe Vorhersagerate als auch eine hohe qualitative geomorphologische Güte auf

SPATIAL TRANSFORMATION PATTERN DUE TO COMMERCIAL ACTIVITY IN KAMPONG HOUSE

ABSTRACT Kampung houses are houses in kampung area of the city. Kampung House oftenly transformed into others use as urban dynamics. One of the transfomation is related to the commercial activities addition by the house owner. It make house with full private space become into mixused house with more public spaces or completely changed into full public commercial building. This study investigate the spatial transformation pattern of the kampung houses due to their commercial activities addition. Site observations, interviews and questionnaires were performed to study the spatial transformation. This study found that in kampung houses, the spatial transformation pattern was depend on type of commercial activities and owner perceptions, and there are several steps of the spatial transformation related the commercial activity addition. Keywords: spatial transformation pattern; commercial activity; owner perception, kampung house; adaptabilit