Mapping of the current state of forest vegetation in the north Baikal Region based on the merging of remote sensing data and ground observations

Abstract

Geoinformation analysis and modeling study of the current state of vegetation (as exemplified by the southeastern macroslope of the Baikal Range, Eastern Siberia) were performed. The phytocenoses of the territory differ from each other in many features, namely in projective cover, ratio of ecological groups, confinement to landforms, epiterranean phytomass, etc. These details help to interpret the types of plant communities based on the values of the calculated vegetation index. We proposed a technique that assumes the joint use of the NDVI and NDWI indices, a digital elevation model (DEM) based on SRTM radar topographic survey data, forest inventory data and materials from field expeditions. The use of the DEM and the indices reflecting the physiological state of vegetation considering their availability of chlorophyll and water helps to arrange the communities under study into groups determined by moisture conditions and biomass supply. To determine the species composition of forest stand, we proposed a method based on the Boolean logic – a decision tree – a schematic representation in the form of a tree structure of a complex decision-making process used in a multi-step analysis. The results obtained show that the use of the relationship between the ratio of plant communities to the moisture factor and their spectral characteristics, taking into account the use of DEMs, enables us to create very informative maps, to improve the reliability of interpretation of satellite information, and to map territories not covered by ground-based surveys with the use of interpolation.