Modelling regional forest industry development in New Zealand
Degree GrantorUniversity of Canterbury
Degree NameDoctor of Philosophy
Planning to link resources, production and markets for the forest sector is characterised by diverse and scattered elements which need to be analysed over long time spans. A wood processing planning model (WPPM), emphasising primary processing at the regional level, has been developed as part of an ongoing programme of forest sector modelling research. The need for such an approach is apparent in the New Zealand industry, where the benefits of formal and end-directed sector planning could be very substantial, particularly in view of the imminent increases in wood supplies. Existing models and modelling efforts in New Zealand and worldwide have not, in general, addressed the specific problems of forest industry strategic planning. They do not adopt an integrated approach to using and growing the resource. Models which incorporate considerations of processing are often over-generalised, or restricted in the time dimension, thus reducing their utility in strategic planning applications. WPPM is formulated as a mixed integer linear program for optimising regional economic benefits from wood processing, with constraints on resource inputs, productive capacities, markets and capital availability, amongst others. Capacity changes are restricted to discrete step sizes in the model, a feature adding to its realism and found in few other applications. Model size is determined by the objective(s) of the user; WPPM can cater for all planning levels from single mills to regional sector analysis. The model structure, function and capability are outlined using a sectoral analysis of the Canterbury region as an example. The results of this analysis, although indicative only, provide insights into likely industrial development which would benefit the region, along with a wealth of information on future "optimal" production levels and sales. The results for the initial planning periods of this case study (1988 and 1989) are compared with the actual state of the regional industry in this period, allowing a limited verification of the modelling system. While these results show that the model captures the dynamics of the region's wood processing sector well, full verification of WPPM will require more extensive use and testing over a range of different objectives.