Wydzielanie kompleksów krajobrazowo-roślinnych na zdjęciach Landsat ETM+ z zastosowaniem procedury region growing

Celem pracy jest delimitacja kompleksów krajobrazowo-roślinnych na wieloczasowych zdjęciach Landsat ETM+. Kompleks krajobrazowo-roślinny to niewielka jednostka geobotaniczna nawiązująca do nanochory w hierarchicznym systemie jednostek fizycznogeograficznych. Kompleksy wydziela się jako względnie jednorodne segmenty obrazu z zastosowaniem procedury Region Growing. Analizowany jest dobór opcji procedury i granicznej odległości euklidesowej (SED). Zalecana jest opcja aktualizacji średniej. Nie stwierdzono możliwości ustalenia konkretnej wartości SED dla poszczególnych typów kompleksów. Stąd konieczność ręcznego doboru SED dla każdego z segmentów.

The aim of the article was the delimitation of landscape-vegetation complexes on multitemporal Landsat ETM+ images. A landscape-vegetation complex is a small geobotanic unit corresponding to a nanochore level of physico-geographical units (Matuszkiewicz, 1990, 1992; Richling, Solon, 2002). A landscape-vegetation complex consists of one or both of the two main components: plant communities (phytocoenoses) and anthropogenic forms of relief and land cover (excavations, water reservoirs, ditches, dams, roads, buildings etc.). A landscape-vegetation complex is useful for mapping terrains under spatially-differentiated anthropogenic pressure. Landscape-vegetation complex may be visually interpreted on diachronic composition of panchromatic data. The composition used in this paper consist of the three bands: - red component: ETM(8) acquired in September, - green component: ETM(8) acquired in May, - blue component: ( ETM(1) + ETM(2) + ETM(3) ) / ETM(8), September data. Nine types of complexes may be distinguished on the composition (Kosiński, 2005): - waters, - build up and railway areas, - pine woods, - broadleaf forests and thickets, - arable lands and four categories of grasslands. In this project, landscape-vegetation complexes have been interactively delimited as semi-homogeneous image segments using a Region Growing procedure. 6 interpreters participated in this work. Procedure options and Spectral Euclidean distance (SED) were interactively adjusted for each segment and different options were tested. The update region mean option was assumed to be recommended. In forest areas, the required spectral Euclidean distance was low and in grasslands it is higher. However, there is no possibility to use one SED value for any type of complex. It may be manually adjusted for each segment. Complexes were classified on the basis of colour component values. Aerial photos and topographic maps were used as additional data.