Optimization of timber harvest-visual space allocation for forested landscape

随着越来越多的土地受到管理活动的视觉影响，公众对环境--包括其审美价值--的关注有所增加。在这些担忧中，最重要的往往是木材采伐的视觉效果。许多木材采伐活动将苛刻和不协调的视觉元素引入到景观中，本研究的重点是：(1)从三个不同的角度确定林分内景观所采用的视觉质量目标；期望的视觉特征、消极和积极的视觉元素。引入层次分析法对影响视觉视域环境建立的各种因素进行评价，克服了视觉特征和要素优先级确定的诸多困难。(2)分析了影响中、背景视距视觉吸收能力的主要景观因素。在t…中定义了景观特征的描述运用德尔菲法对要素、原理和变量进行了更多的误差修正。对上述景观的分析表明，视觉吸收能力受到地形、坡度、对比度、与重要位置的距离等因素的很大影响。(3)通过生成透视图来展示所建议的替代木材采伐/道路布局系统，从而产生森林景观的视觉设计技巧。图纸显示了所选观察点的变化情况，并将景观显示为变形正方形的网格或代表树木、道路、空地、天际线走廊等的符号。拟议的图形系统创建了切割单元边界线和其他关键地标特征的准确透视表示。这允许设计师和情节之间的即时互动，并快速地前后收敛到最佳设计。这些信息应该对景观设计师和伐木工程师有用，以规划符合视觉影响的木材采伐。较少

Public concern for the environment -including its esthetic values- has increased as more and more land has been visually affected by management activities. Often foremost among these concerns has been the visual effect of timber harvesting. Many timber harvest activities introduce harsh and incongruous visual elements into the landscape.The main points of this research are to:(1)identify visual quality objectives adopted for the viewshed within the forest stand from three different perspectives;desired visual characters, negative and positive visual elements. The AHP-system was introduced to estimate various factors which affected establishment of visual viewshed circumstances and it could overcome many of the difficulties of the priority determination on desired visual characters and elements.(2)analyze predominant landscape factors that affect the visual absorption capability in the middle- and background viewing distances. The description of the landscape characters was defined in t … More erms of the elements, principles and variables by employing the Delphi-method. An analysis of landscapes above showed that the visual absorption capability was much affected by landform, slope, contrast, distance from significant positions, etc.(3)produce visual design techniques of forested landscapes by generating perspective drawings that show proposed alternative timber harvesting/road layout systems. Drawings show how changes would appear from selected viewing points and show landscapes as either a grid of distored squares or by symbols representing tree, roads, clearings, skyline corridors, etc. The proposed graphic system created accurate perspective presentations of cutting unit boundary lines and other key land mark features. This permits immediate interaction between the designer and the plot, with rapid back and forth convergence towards the best design.The information should be useful to landscape architects and logging engineers teamed for the purpose of planning timber harvests that meet visual impact. Less