FERIC conducted a synoptic survey of 102 landslides on the Queen Charlotte Islands, 97 of which originated within logged areas, to provide forest engineering input into the interpretation of probable causes and possible preventative measures. The principle factors in road-related landslides appeared to be overloading of steep slopes with fill or sidecast material and inadequate control of road drainage. Specific causes for landslides that initiated within clearcuts but away from roads could rarely be identified. However, the yarding process probably accelerated landslide activity at critical points where poor deflection generated severe yarding disturbance on sensitive slopes.
The objectives of the handbook is to provide members of the forestry industry with a guide for locating, designing or modifying a dryland sortyard. It provides comprehensive, factual information that can be followed in a step-by-step fashion. It stresses sortyard system analysis and design rather than construction details. Concepts of management science and their application in the selection and design of a sortyard are discussed. Current costs and productivities of sortyard and sorting systems are given. Many of the subjects discussed in the handbook apply to other areas of logging.
This report is a review of available information on the influence of yarding systems on erosional processes in the Pacific Northwest and the Queen Charlotte Islands. Literature was reviewed and the relevance of these studies to Forest Harvesting on the Queen Charlotte Islands are discussed, and discussions with local Queen Charlotte Islands' Forest Company and Agency Staff are Incorporated. Yarding systems that were considered potentially effective in reducing mass wasting are also noted.
The free-flying aerial logging vehicle is an attractive alternative to conventional cable logging systems on steep slopes, because it requires fewer roads and landings, permits shorter operational lead times and reduces environmental impacts. Helicopter are being used to log high value timber, but high operating costs and limited payloads often offset the advantages. Heavy-lift airships, combining both static (helium) lift and aerodynamic lift, may offer a lower-cost alternative. Much of the world's remaining high quality timber is on areas too inaccessible for too environmentally sensitive for economical logging by current methods. The cyclocrane and other heavy-lift airship developments show promise for overcoming these obstacles.
This report discusses the process of planning logging operations on steep, unstable terrain on the Queen Charlotte Islands, British Columbia. The report describes the current logging planning process, its data requirements and methods of data collection, and the results of a series of alternative logging plans prepared to minimize the potential for logging-accelerated mass wasting. Recommendations are also make for improving the planning process through the amount and quality of data required, evaluating alternative plans, and logging- system selection. Intensive ground mapping on two watersheds provided data for the preparation of detailed logging plans. The logging plans incorporated various combinations of equipment, including equipment that was in common use at the time.
Fourteen yarding settings on eight different sites on the Queen Charlotte Islands were monitored to measure productivity and evaluate logging system. Effectiveness, to document yarding disturbance, and to determine how disturbance may contribute to landslide initiation. Twenty-three landslides occurred on or near the study areas, of which three occurred in adjacent control areas of no logging, and four occurred prior to yarding and were probably associated with discharge of road drainage. Of the sixteen failures that occurred within the yarded areas, fourteen had direct evidence of yarding disturbance in their initiation zones. Nine of the failures (four road associated, three non-logging associated, and two yarding associated were over 200m2 in area6