Выявление ключевого биотопа бореальных пойменных лугов в национальном парке «Смоленское Поозерье» на основе спутниковых и топографических данных

Abstract

The research shows the possibility of identifying a key biotope of boreal floodplain meadows in the Smolenskoe Poozerye National Park on the basis of spectral and topographic characteristics of the territory. The key biotope E3.47 according to EUNIS is a meadow along large rivers with areas of calm flow; it freeze every winter and affected by flooding in spring. This category includes areas that are open or poorly overgrown with woody and shrubby vegetation. Sentinel-2 multispectral satellite images (ESA Sentinel-2, 2019) are used to determine areas of floodplain meadows. The geospatial assessment of boreal floodplain meadows is carried out using the method of uncontrolled classification of “K-means” of ten spectral channels of Sentinel-2 satellite images obtained over six seasons, including the flood period. As a result of cluster analysis, classes that are spectrally close to meadow communities are selected. These classes located along flood-plains of rivers, with the elevation difference from the water line not exceeding 5 m. This elevation corresponds to the maximum possible rise of water in rivers during a flood for the studied area. A topographic index using a digital elevation model (DEM) and a hydrographic terrain network are used to correct the selected classes. The accuracy of recognition of the floodplain meadows class is determined using a matrix of error in 133 segments along the 4 transects located in floodplain and dry meadow communities. The convergence of result between the floodplain meadows classification and ground surveys data was 75% (Cohen’s kappa equals 0.53).