EXPERIENCE OF VEGETATION INDICES USE FOR COMPLEX RESEARCHES ON THE OBJECTS OF HYDRO AND FOREST AMELIORATION

Abstract

The remote sensing data can be used for study and inventory of forests, study of forest structure and forest state. Nowadays,  spectral or vegetation indices are widely used for the purposes. Relationship between some vegetation indices (NDVI – Normalized Difference Vegetation Index and LWCI – Leaf Water Content Index) and distance from sample plots to drainage ditches, between these indices and some taxation forest stand parameters are studied in the paper. Research was carried out in Troitsko-Pechorskiy forestry of Komi Republic. The results of research taken place in the Kortkerosskiy forestry were used for comparison. In the first years after drainage NDVI weakly negatively correlates with distance from stands to ditches. In 10 years after drainage a negative correlation is also observed between the indices (R=0,35; R_0,05=0,37; R_0,10=0,32; N=29). This result is coordinated with the idea that NDVI is an index of phytomass and it is larger near ditches. At the shallow peat bogs it is necessary to take into account peat thickness when studying dependence of the NDVI index from distance to ditches. LWCI is weakly positively correlated with distance from sample plots to drainage ditches in the first years after drainage. Perhaps, it is the result of trees stress caused by water regime change. In 10 years after drainage, medium negative correlation is observed between these indices (R=0,55; R_0,05=0,37; N=29). It can be the consequence of trees adapting to the changed water regime. That is why LWCI index is larger close to ditches and less in the middle of strip between the ditches. NDVI is qualitatively connected with the volume of spruce, fir and Siberian cedar and with the density of natural reforestation. That indicates to perspective of use of this vegetation index for estimation of forestry drainage effect.