Review article
Application of Aerial Photographs in Forest Management in Croatia
Ivan Balenović
orcid.org/0000-0001-7422-753X
; Hrvatski šumarski institut Jastrebarsko
Hrvoje Marjanović
; Hrvatski šumarski institut Jastrebarsko
Miroslav Benko
; Hrvatski šumarski institut Jastrebarsko
Abstract
In forest inventory, in Croatia, data acquisition is performed using exclusively terrestrial methods which are costly and time consuming. With application of remote sensing methods, the need for the field work is reduced which might open the possibility of reducing costs. In the last thirty years various research about possibility of applying remote sensing methods in practical forestry in Croatia were conducted. But, practical applications of data obtained by remote sensing methods were limited mainly to their use for the orientation in the field.
Classical photogrammetric methods were one of the methods that were tested, but also did not find wider application in practical forest inventory. However, development of new digital image acquisition and processing technology has encouraged us to reconsider the application of digital photogrammetry in the forest inventory. The aim of this work is to give contribution in determining the guidelines for application of aerial photographs (digital images) in practical forest management.
In the last thirty years photogrammetry developed from analogue, over analytical to digital photogrammetry. Film based aerial photographs are still used in analogue and analytical photogrammetry, and photointerpretation is performed with analogue or analytical stereoinstruments. In digital photogrammetry film based aerial photographs are replaced with digital images, and photointerpretation is preformed using specialized computer 3D monitor. In the last decades, digital aerophotogrammetric camera (Figure 1) and digital photogrammetric workstation (Figure 2) became the most important tools of digital photogrammetry, especially in geodesy.
In this paper we presented the overview of the past research and results of application of aerial photographs in forest management in Croatia. Research of stand delineation, tree and stand attributes, and other application of aerial photographs in forest management are presented. Most of those researches were carried out with photointerpretation and photogrammetric measurements on film based aerial photographs with analytical stereoinstruments. However, several pioneering researches using digital image analysis were reviewed here as well.
We presented the current state of the technology in the field of digital photogrammetry. Also, a review was given of several selected research from Europe, which described the possibility and limitations of application of modern photogrammetric methods in forest management. Overview of domestic and foreign literature indicates that an application of digital images of high spatial resolution, which can be obtained from digital aerophotogrammetric camera for use at digital photogrammetric workstations, are insufficiently explored, especially for application in forest management. One possible area of application of digital photogrammetry in Croatia is in the management of private forests. Because of the lack of proper management and of inventory data for private forests, we can assume that digital photogrammetry could prove useful in this area of forestry. This could lead to reduction of the required field work and related costs in creating forest management plans. In addition, when obtained, high resolution digital images of forested area are an important document that could be used in future (research and monitoring of growth, forest health, harvesting, etc.). Should costs in data acquisition for forest inventory by employing digital photogrammetry prove to be lower (or in worst case only slightly higher) that those employing classical methods, this should be a strong sign to the forestry community in Croatia to consider the use of digital photogrammetry in forest management.
Keywords
aerial photographs; digital photogrammetry; remote sensing; stand parameters assessment; stands exclusion
Hrčak ID:
62794
URI
Publication date:
31.12.2010.
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