Monday 10. September – Wednesday 12. September

SOKRATES INTENSIVE PROGRAMME

MOUNTAIN RISK MANAGEMENT

Coordinator: Karl Kleemayr

Programm:

Morning presentation

Goal:

The participants should get the basic knowledge for management decisions about cable logging. The understanding of the mechanical principles of cable systems and the knowledge of the systems and elements should give them the basis for decisions at the management level.

The demonstration in the forests should support the theoretical.

Content:

Mechanics

Basics of cable mechanics should help to understand the way cables work. The different types of cables are presented. Safety rules and principles for calculation on design of forest cable systems are explained.

Cable Systems

The different cable systems will be presented and discussed as a comparison of European and Northern American systems. The comparison is structured:

Carriages:

Overview on the different types of carriages. Explanation and demonstration of the functions:

1. Carriages for uphill yarding
2. Carriages for downhill yarding

The explanation is done on drawings and real carriages.

Intermediate Supports:

Intermediate supports are a specific element of European forest cable set ups. The common types are explained theoretically . The design and the way to construct supports is part of the course. The construction exercise is done on 1:10 modells in the lab and will also be done at the demonstration sites in the afternoon.

Afternoon presentation:

Field trip( local Ossiach):

Demonstration of different cable systems in the forest. At the demonstration sites the systems have to be discussed in the aspects of productivity, sustainability and safety. The participants can try to operate the different systems.

Goal-Content:

Demonstration of the possibilities and problems of protective forests in steep terrain. Hydrological and geomorphological aspects, typical for forests in alpine regions, will be discussed. In addition, technical measures of the torrent and avalanche control will be seen. The students will be practically confronted with the numerous requests of road planning in steep terrain. A deputy of the torrent and avalanche control will participate this and the next day in order to demonstrate the problems from a very practical point of view.

Morning presentation

Goal-Content:

Very shortly, basic concepts of flood and avalanche as well as political control measures will be presented. Various modelling techniques

Technical measures, prediction tools and hazard zoning as used in Austria will be sketched. The presentation should give a rough imagination of the processes and protection possibilities.

The presentation deals with the question, how mountain forest management concepts are developed by the forest administration in practice. This is illustrated by examples from different administrational bodies in Austria as well as from other Alpine countries. To what extent do mountain forests protect against natural hazards? Do mountain forests even produce risks? Do mountain forests have to be managed in order to secure their protective functions? These are no uncontentios questions between foresters, nature conservation groups, etc. Different groups have different concepts and conceptions of risk. In Switzerland, an intensive discussion between foresters and conservationists has resulted in a changed attitude of the forest administration towards wind-throw in mountain forests: wind-throw areas are not always harvested in mountain areas any more – as it was the former policy. In Austria, two institutions are active in maintaining forests, which protect against natural hazards. They apply different routines: the forest authority follows a vague concept of multifunctional forest management. The torrent and avalanche control service, in contrast, focuses more precisely on the reduction of certain hazards. While the first is primarily oriented at the forest owners' interests, the latter concentrates on the interests of the beneficiaries of protective forests. The applied risk policies are strongly determined by the different stakeholders' interests, who participate in the corresponding policy-networks. Within different institutional settings, official experts develop different risk concepts and consequently different solutions.

Since the nineteenth century extensive areas supporting broad leaf species in warmer and drier lowlands in Central Europe have been transformed to conifer plantations dominated by Norway spruce (Picea abies (L.) Karst.) due to its superior productivity and wood quality compared to the native broad leaved species. Substantial areas of these secondary coniferous forests are characterized by site properties such as increased frequency of drought periods and gleyic soils where Norway spruce is periodically close to its ecophysiological limits and particularly vulnerable to windthrow and an array of insect and desease organisms. Further undesirable effects of these coniferous forests are, that multiple rotations of Norway spruce may lead to soil compaction and increased soil acidification, depending on site conditions. These effects are mainly due to the shallow rooting system which may cause nutrient exploitation of the most upper soil horizonts, and the capacity to accumulate substantial quantities of nutrients in leave biomass, which may result in decoupled nutrient cycling. To improve crop reliability and to reduce economical and ecological risks, the conversion of pure Norway spruce stands into mixed-species stands, which are better adapted to the particular site conditions, is recommended. The development of sound stand conversion programms currently is one of the key issues in European silvicultural research. In view of a complex decision space with many site and stand attributes involved, the use of decision support tools can provide substantial help in the decision making process.

Decision support systems (DSS) can provide valuable support to solve ill-structured decision problems (Rauscher, 1999; Vacik, 1999). In general terms, DSS are computer-based systems for integrating data base management systems with analytical and operational research models, graphic display, tabular reporting capabilities and the expert knowledge of decision makers to assist in solving specific problems. DSS featuring mechanisms for the input and use of spatial information as well as for the output of maps are spatial decision support systems (SDSS). As DSS are based on formalized knowledge, their application in the decision making process facilitates decisions that are reproducable and as rational as possible. Moreover, through the use of DSS, the way the decision maker arrived at a decision is automatically documented, and thus the process of decision making can be evaluated.

In this contribution we outline the purpose and fundamentals of SDSS for silvicultural planning and decision making in low-elevation Norway spruce forests. The core structure of the spatial decision support system has four main components: the information base, the tool box, the SDSS generator where the decision model is embedded, and a graphical user interface (GUI). In this example the information base is implemented in Microsoft^®Access and conceptually consists of a database management system and a modelbase management system. The information base contains data either directly obtained from measurement of the decision objects or generated by models from the model base. The content of the tool box consists of implementations of selected elements from the field of MCDM-methodology and selected spatial analysis methods. The implementation of the decision model (i.e., the sequence of algorithms which are used to evaluate the decision alternatives) relies on tool box and information base where the objectives, the a priori defined set of decision alternatives, as well as the decision constraints are stored. The linkage of data and models is facilitated through the SDSS generator. For entering, processing, and storage of spatial information the geographical information systems (GIS) ArcView^® 3.2 is employed.

The species suitabilty model is one part of the modelbase management system. A static model is employed to rate the ecophysiological suitability of tree species for given site conditions (Lexer et al., 2000). The effect of a selected set of site parameters representing the water supply, nutrient status and the thermal regime at a site on ecophysiological suitability of tree species is modelled by means of a fuzzy logic control unit. To evaluate the overall utility of decision alternatives in case that more than one possible solution exists, an approach that borrows from multiple-attribute utility theory (MAUT) is adopted. A hierarchical structured utility function was developed to calculate the value of a decision alternative with respect to the management objectives (e.g. income from timber production, reduced risk of management, sustainable site productivity, maintance of biodiversity). Additionally the analysis of spatial data is greatly enhanced by the integration of MapModels (Riedl et al., 2000), a flow-chart based programming routine. MapModels enables the user with no particular skills in electronic data processing to adapt analysis methods to a spatial decision problem.

The graphical user interface (GUI) provides the possibility to visualize information from the data base and results of decision analysis procedures. To enhance the interaction between the decision maker and the SDSS, we decided to modify the standard graphical user interface of ArcView. A hypermedia systems which contains text, figures and tables will inform the decision maker about decision alternatives (e.g. costs, silvicultural treatment options, tree species suitability, growing stock objectives). A display and report generator enhances the decision maker to visualize the results of a decision and compare alternatives. Sensitivity analysis, one of the powerful tools of decision support systems, can be performed. The outcome of different results with varying preferences of the decision maker with respect to management objectives can be evaluated. The repeated use of the display and report generator might help the decision maker to reorganize and structure the decision problem or adapt silvicultural treatment options.

Regarding the current pre-prototype version of the SDSS outlined herein we admit a major technical limitation: lack of flexibility regarding the system implementation. For instance, in the current version the structure of the presented decision model has to be modified by an expert in electronic data processing. Future improvements aim at developing a more flexible SDSS generator that will enable the user to combine elements of tool box and modelbase to taylor a decision model to the specific needs of a particular decision problem.

Literature

Riedl L.,Vacik H., Kallasek R., 2000: MapModels: A new approach for spatial decision support in silvicultural decision making (in press Computers and Electronics in Agriculture.

Lexer M.J., Hönninger K., Vacik H., 2000: Modelling the effect of forest site conditions on the ecophysiological suitability of tree species: An approach based on fuzzy set theory (in press Computers and Electronics in Agriculture).

Rauscher, M.H., 1999. Ecosystem management decision support for federal forests in the United States: A review. For. Eco. 114, 173-197.

Vacik H., 1999: Einsatz von entscheidungsunterstützenden Systemen und geographischen Informationssystemen in der waldbaulichen Planung, Dissertation am Institut für Waldbau, Universität für Bodenkultur.

The presentation deals with dynamical avalanche model and avalanche release prediction models. The demand for computational hazard evaluation models increased strongly in the last years. Though the possibilities significantly permanently increase basic problems of modelling catastrophic events remain. The student will be confronted with the topic in a very discerning way and can verify the plausibility of the models by some simulation results.

Suggested literature:

D., McCLUNG, P. SCHAERER , 1993: Canadian Avalanche Handbook, The Mountaineers

Afternoon presentation:

Field trip to PARTERGASSEN

Goal-Content:

Demonstration and discussion of various avalanche and rockfall control measures. A protective forest project will be presented by the torrent and avalanche control and discussed with the students.