Determination of the Pyro-Factor Ecological Successions Duration in the Zonal Landscapes of the Volgograd Region According to the Remote Sensing Data

The aim of the work is to determine the spatial characteristics of the distribution of the burnt areas of natural zonal landscapes of the Volgograd region with different duration of pyro-factor successions, taking into account the frequency of fires. Based on the previously developed thematic geo-information layers of the steppe fires in the region using overlay operations, the duration of post-pyrogenic periods in the municipal districts of the region was determined, taking into account the total number of fires from 1998–2018. The largest areas covered by fire have a succession duration of 2–3 years and 12–14 years at the beginning of 2019, which corresponds to the fires of 2016–2017 and 2005–2007, respectively. Large areas after the fires of 2001–2002 are located in Ilovlinsky, Kletsky, Pallasovsky and Surovikinsky districts. The largest area of land covered by fire in 2004–2006 is located in the Danilovsky, Ilovlinsky, Olkhovsky and Pallas districts. In our opinion, landscapes affected by fire no more than 5–7 years ago are suitable for the analysis of pyrogenic shifts. These territories are located in Frolovsky, Chernyshkovsky, Kotovsky, Ilovlinsky, Pallasovsky, Leninsky, Kamyshinsky, Staropoltavsky districts. The results will serve as the basis for field studies and the analysis of the spectral characteristics of overgrowing burns from remote sensing materials.

Mathematical Modeling of Steppe Fires

The chapter presents a mathematical model of the initiation and spread of the steppe fire. The mathematical model is based on the laws of mechanics of multiphase reacting media. The main physicochemical processes describing the drying, pyrolysis, and combustion of gaseous and condensed pyrolysis products are taken into account. As a result of the numerical solution, the distributions of the velocity, temperature, and concentration fields of the components of the gas and condensed phases were determined. The dependence of the rate of spread of the steppe fire on the main parameters of the state of vegetation cover and wind speed was studied. The mathematical model presented in the chapter can be used to predict the spread of steppe fires for various types of steppe vegetation and meteorological conditions, as well as for preventive measures.