德国北部挪威云杉林可持续经营计划中空间目标的优化

根据德国北部挪威云杉林相邻林分问的特定地理关系,包括林分重心间的距离和共同边界的长度,建立了德国北部挪威云杉林经营的一个空间优化模型,该模型是一种新的空间优化方法.地理数据从GIS中获得并保存到数据库中,数据库还包括林分选项和相应的目标方程值等内容.首先使用了一个由41个林分组成的林班,每个林分21个选项,采用模拟退火的方法来分别和综合优化经济模型、均衡产出模型和空间模型,并将它们的结果方案与具最大净现值的方案进行比较.当均衡产出和空间2个组成部分逐一加入到目标方程后,它们显著地改进了结果方案,而经济目标只有中等程度的下降.

Optim isation of SpatialObjectives in Plann ing for Susta inable ForestMedium-termManagement of Norway Spruce from Northern Germany

The paper p resents a planningmodel for a Spruce forest in northern Germanywith a three-component objectivefunction (economic, even flow and spatial). The spatial modeling approach followed in this analysis relies on specificgeographic relations among neighboring stands, including the distance between stand centroids and the length of thecommon boundary between adjoining stands, representing a new approach in spatial optimization. The geographic data arederived from a GIS system and stored in a database, which includes also all stand options and the corresponding objectivefunction coefficients. The method is first applied, using a relative small forestwith 41 stands. 21 alternative options aredeveloped for each stand and the Simulated Annealing algorithm is used to produce an optimum schedule of operations.Solutions are presented for different objective function components and compared with maximum net presentworth. Whenthe even flow and spatial components are added in the objective function, the effects of these two componentsconsiderably improved the solution, while the economic objective is onlymoderately reduced.