Vegetation Color Indexes of UAV and NDVI in Identifying the Features and Dynamics of Vegetation of Steppe Hayfields

The development of wildfires poses a threat to the sustainable ecological development and safety of the population of steppe regions. One of the factors in the formation of fire situations is the spatial structure of hayfields. In this regard, comprehensive studies were conducted on the site of an old-age steppe deposit in the Southern Urals to identify the relationships between spectral (NDVI) and color (NDI, ExG, ExGR) vegetation indices and the amount of phytomass on conditionally controlled and mowed sites. The results obtained indicate the multidirectional nature of vegetation restoration after haymaking based on the characteristics of the hydrothermal regime of individual years and seasons. In dry years, the vegetation of the hayfield can remain in a depressed state, in wet years it can actively increase the green phytomass with a predominance over the control areas. The use of UAVs is recommended for mapping hayfields, selecting and representative placement of monitoring sites, as well as for obtaining schemes for the distribution of color vegetation indices in conditions of rapid changes in vegetation cover and, if necessary, guaranteed systematic observations.