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.
Preparation and validation of digital maps of geology and slope instability
This paper is concerned with a description of the techniques for the development of digital maps of geology and slope instability. The validation of such maps by field inspection and checking is highlighted. These techniques have been used successfully for the suburbs of the northern Wollongong region of New South Wales. Such maps allow the flexibility of future modifications as additional and or more reliable data becomes available. These maps will facilitate decisions on the planning and management of land use. Currently, 295 cases of land instability have been documented within the study area. The maps are also expected to be useful for the development of reliable hazard and risk assessment procedures.
New Strain Meters for Geophysics
IN the past two months, three ultra long period linear strain meters have been successfully operated in the United Kingdom. Their design is novel and of interest because of the growing attention being paid to long period seismology and the study of earth tides. Here we briefly describe the three, display the first records obtained from them and outline what we may expect to use them for in the future.