Effective urban landslide hazard assessment
Landslide hazard assessment is a vitally important component of any strategy for the management of risk of instability in hilly areas. Within many urban areas, reactivation of landslides is an important component of risk. Yet, most qualitative approaches do not differentiate between the hazard of individual landslides. Two quantitative approaches are introduced in this paper both of which utilise GISbased accurate maps of geology and landslip as well as a landslide database. The first method is based on historical recurrence of individual landslides. The second method is based on monitoring of subsurface shear movements, and their relationships to rainfall. Both methods can provide reliable information on hazard. Hazard ranking based on the first method has been validated in the Greater Wollongong area of the State of New South Wales in Australia. This paper does not address the potential hazard associated with sites which are recognised to be stable with no known history of instability.
A landslide database for landslide hazard assessment
Assessing the hazard and risk of slope instability and landsliding requires a consideration of basic geological and geotechnical factors which control stability as well as external agents or events which decrease stability and which may trigger landsliding. Prediction of slope performance is difficult and it is, therefore, considered appropriate to develop approaches for hazard and risk assessment. This paper is concerned primarily with one important aspect or element of such an approach. The essential and desirable features of a landslide database are outlined with particular reference to an urban area in New South Wales, Australia. The procedures and processes for developing such a database are introduced and attention is given to uncertainties which are associated with the processes of identification, mapping and describing landslide sites. Several features of a database which was recently developed are described and discussed.
Organic geochemical characteristics and depositional setting of Tertiary organic-rich sediments from onshore Penyu Basin , eastern Chenor , Pahang , Malaysia
Poor knowledge of the organic facies characteristics of the eastern Chenor Pahang has made it remain an untapped potential in the Penyu Basin. Therefore, detailed geochemical and petrographic characterization of the Tertiary organic facies of the eastern Chenor area of the Penyu Basin was carried out to characterized its organic matter (OM) source input. Towards achieving the goal, this study focuses on determination of organic matters richness, type and origin as related to their paleoenvironmental conditions of the carbonaceous mudstone and shale using organic petrography combined with organic and inorganic geochemistry. The sedimentary succession is characterized by fine to coarse grained sandstone occurring in association with carbonaceous mudstone and shale in a predominantly fining upward sequence within a lacustrine environment. These facies are generally enriched in organic matter as indicated by the TOC results, hydrocarbon yield (S2) and extractible organic matter (EOM), suggesting significant hydrocarbon generation potential for the area.