Use of digital aerial photography for sub-alpine vegetation mapping: A case study from the Krkonoše Mts., Czech Republic

摘要: Multispectral aerial photographs from 1986, 1989 and 1997 were used for mapping assessment of changes in sub-alpine vegetation the Krkonose Mts Plateau (1300 to 1400 m a. s. l.), Czech Republic. Scanned digitally processed by various remote sensing methods, such as histogram equalization, principal component transformation, Normalised Difference Vegetation Index, classification (both unsupervised, i.e., Iterative Self-Organizing Data Analysis Technique, supervised, Parallelepiped Maximum Likelihood algorithm). The results geometrically corrected registration into orthophoto images. Field data 1991 assisted class labelling description. A detailed analysis was conducted using multispectral since field-verification comparison ground-based map could be done with only two-year difference. unsupervised resulted six classes (three them mixed) a 60.6% overall accuracy unmixed classes. Some important types not separated. supervised nine 81.1%. most common were: mat-grass communities (40.4% total area) tall grass herb (23.1%). Pine stands, best separated types, evaluated on 1986 P. mugo stands doubled area over 10 years. aerial-photograph based maps compared an available obtained field survey. correspondence between both ranged 24 – 75%, highest values pine communities. In survey, photography provided less detail characterized mostly dominant species. approach failed small patches heterogeneous or atypical differentiate dominants similar appearance. Nevertheless this method is comparably time- labour-consuming, it seems suitable distinct surveying larger areas identifying time.