Evaluating hillslope stability in tropical karst , 1998, Gillieson, David

Residential development in the tower karst of the Kinta valley, Malaya is proceeding at a rapid pace, and many developments have been subject to damage and loss of life from landslides and rockfalls. Study was conducted at Gunung Tempurung- Gajah, a 600-metre high limestone tower. The evaluation of hillslope stability was made by geomorphological mapping including the parameters: type of slope, activity of landslides and rock stability. Over geological timescales, periodic landslides and rockfalls are a normal and expectable part of the geomorphological processes in the tower karst of the Kinta valley. The expected frequency of landslides today is difficult to determine but recourse can be made to data on the frequency of high-intensity rainfall, and examination of revegetation on landslip debris. From these data, it seems probable that minor landslides can be triggered every 2-3 years in the area, with major phases of landslide activity occurring every 20 years.

Working with knowledge at the science/policy interface: a unique example from developing the Tongass Land Management Plan, 2000, Shawiii Charles G. , Everest Fred H. , Swanston Douglas N. ,

An innovative, knowledge-based partnership between research scientists and resource managers in the U.S. Forest Service provided the foundation upon which the Forest Plan was developed that will guide management on the Tongass National Forest for the next 10-15 years. Criteria developed by the scientists to evaluate if management decisions were consistent with the available information base were applied to major components of the emerging final management strategy for the Forest. While the scientists remained value neutral on the contents of the Forest Plan and the management directions provided in it, their evaluation indicated that the decisions it contained for riparian and fish sustainability, wildlife viability, karst and cave protection, slope stability, timber resources, social/economic effects, and monitoring achieved a high degree of consistency with the available scientific information. The Forest Plan, revised to conform with existing scientific knowledge, represents a management strategy designed to sustain the diversity and productivity of the ecosystem while producing goods and services commensurate with the agency’s multiple-use mandate. Execution of this research/management partnership highlighted the role of scientific knowledge in forestry decision-making and provided a new mechanism to input such information into the decision making process. The partnership continues as the scientists are addressing high priority information needs generated by the planning effort in order to have additional information available for plan implementation and revision through adaptive management over the next 3-5 years

The situation and dynamics of the North Yorkshire windypits: A geophysical and geomorphological investigation, MSc Thesis [Engineering Geology], 2002, Devlin, R.

ub-surface slip-rift fissures and shafts, known locally as 'windypits', are numerous in the Upper Jurassic strata of the Hambleton Hills and Ryedale district of North Yorkshire. Windypits are predominantly open gull-formations, formed as a result of cambering between competent Corallian Group sandstone and limestone beds above weak clay beds of the Oxford Clay Formation. They relate to the natural pattern of steeply-dipping, widened joint-plane discontinuities, with individual blocks of caprock moving relative to one another along these surfaces. The most extensive fissure systems are up to 40m deep and over 300m long, and typically run sub-parallel to slope contours and linear topographic features, rupturing the surface above the line of maximum gradient. More complex and unpredictable structures occur where there is more than one direction of movement, resulting in a radial fissure network. Windypits have been associated with other forms of scarp recession and landslide activity, most notably the formation of unstable block detachments along vertical cliff-exposures. Aerial photographic interpretation and terrain analysis based on field observations and mapping have been used here in a detailed geomorphological investigation of windypit structures and their related landforms. They appear to play a significant role within a far more complex model of superficial slope evolution, with important consequences for rock-slope stability. The potential hazards from landslides and natural cavities are also assessed in the light of engineering geological evaluation. Shallow geophysical surveying techniques have been used to profile the electrical contrasts between void space and host rock, at a number of selected sites. It has been found that non-contacting electromagnetic conductivity methods are unsuitable for producing a discrete windypit anomaly, due to their limited depth of penetration. Tomographic resistivity techniques appear to be the most promising for accurately locating sub-surface fissures, and helping to map their true depth and full extent Comprehensive ground investigation would allow better interpretation of the geophysical data collected.