Radovi, Vol. 40 No. 1, 2005.
Prethodno priopćenje
Application of digitalisation of crowns and method Of visualisation in a study of stand structures
Tomislav Dubravac
Sažetak
The paper presents the possibilities of a new method for the study of stand structures by crown digitalisation and production of a three-dimensional model of stands (visualisation). An investigation was carried out in a natural mixed stand of Peduncled oak and Common hornbeam (Carpino betulli-Quercetum roboris, /Anić 1959/ emend. Rauš 1969) and in a beech and fir stand (Omphalodo vernae-Fagetum, Marinček et al 1992). On experimental plots of permanent character all trees were marked by numbers and mapped, and d b h, tree heights and stem lengths measured and horizontal crown projections recorded. Crown projections were then digitalised in the CAD programme MicroStation, application IRAS B with mean accuracy of 4 cm. Geo-coding and functions of equation were performed by Affin transformation (coordinate projection from one plane-source coordinating system into another plane-exit coordinating system) and by transforming the raster file into vector form; also in the programme MicroStation. On the vector planes without canopy within the area (plot) and surfaces under crowns outside the area (plots), were calculated. Data were then transferred into the AutoCAD 2000 dwg programme for the purpose of simplification of presentation. Crown projections were completed by the vertical profile (Corel Draw) of the stand, which proportionally shows the relation between basic elements of the crown and stem. A three-dimensional model of the stand was made based on the measured dimensions of trees in the field and by the computer programme 3DS Max. The corresponding texture of crowns was added to the model, which resulted in a clearer presentation of the situation. During construction of the model attention was paid to the spatial distribution of trees, tree heights, stem lengths, lengths and widths of crowns and phenotypical forms of crowns of oak, hornbeam, beech and fir. Seed - cutting was simulated in the stand of Peduncled oak and Common hornbeam and shown in three-dimensional form. The models enable computer monitoring and simulation of management measures in a stand and present new possibilities for solving and using existing information, and their application can be found in aerial-photography estimation and GIS. Methods of three-dimensional visualisation can serve for the presentation of natural development of stands, visual comparison of stands before and after intervention, as well as for the change of the paradigm (example-pattern) in forestry research from whole-stand observation to investigation of an individual tree
Ključne riječi
stand structure; crown projections; digitalisation; three-dimensional model; oak; hornbeam; beech; fir
Hrčak ID:
4016
URI
Datum izdavanja:
26.9.2005.
Posjeta: 1.633 *