ASSESSMENT OF RESTORATION DYNAMICS OF BURNT FOREST AREA VEGETATION USING LANDSAT SATELLITE DATA

Известия Томского политехнического университета: Инжиниринг георесурсов

Olga A. Pasko¹  Ahmet D.A. Alshaibi²  Olga S. Tokareva³ 

[1] Agrophysical Research Institute;General Department of Education, Diyala;National Research Tomsk Polytechnic University;

关键词: ndvi;    burnt forest area;    vegetation cover;    remote sensing;    nbr;    forest fire;   

DOI  :  10.18799/24131830/2021/7/3283

来源: DOAJ

【 摘 要 】

Relevance. Up to 400 thousand forest fires that occur annually on Earth lead to the release of up to four billion tons of carbon into the atmosphere and the burning of up to 0,5 % of the forest area. Forest fires destroy wood resources, reduce the efficiency of their use, and cause enormous damage to the economy. Operational and objective information about their consequences is in demand for solving a set of theoretical and practical problems in the field of land management, cadastre and monitoring of forest lands, as well as for scientific justification of the use, restoration, conservation and protection of forests. Object: forest lands that exposed to fires. Subject: post-pyrogenic dynamics of vegetation cover on the example of forest harems of the Tomsk region. Methods: thematic mapping of the territory according to the state of vegetation; estimation of the amount of photosynthetically active biomass NDVI (Normalize Difference Vegetation Index) and normalized burn index NBR (Normalized Burn Ratio) according to remote sensing data; use of satellite images from the archive of the US Geological Survey and the Internet service Earth Explorer 1999–2017; analysis of information from Landsat satellites 5 (camera TM), 7 (ETM+) and 8 (OLI) using geoinformation technologies and statistical processing of the received data. Results. The authors have assessed the vegetation state of the burnt forest areas in comparison with the background forest area of similar breed composition (46 % – Siberian Pine, 36 % – Hanging birch, 11 % – Common Aspen, 7 % – Common Pine and Siberian Larch). The disturbance of the vegetation of the studied burnt forest areas is characterized as low. The study uses Landsat satellite images acquired in the period from 1998 to 2016 and obtained from the archives of the US Geological Survey. The NDVI and NBR were calculated for the burnt forest areas and background areas. Sharp differences in their values and anomalous course of annual dynamics for burnt forest area are revealed. The NDVI values for the burnt forest areas and the background area differed by 3–56 %, and the NBR values by 20–198 %. The differences persisted 17 years after the fire. The correlation analysis revealed a significant relationship between the values of the NBR and NDVI of the burnt forest areas and the average values of air temperature and precipitation in the fire season. It turned out to be negative medium and weak strength for May; strong and medium for July and weak for August. Precipitation is associated with the values of the NBR and NDVI of the burnt forest areas with an average strength: negative in May and June, positive in August. This indicates sufficient moisture of the ecotopes at the beginning of the growing season, subsequent drying of the soil, optimal for the vital activity of trees, and its desiccation, which determines the possibility of forest fires. There is a clear territorial variability of the NDVI and NBR values within the burnt forest area boundaries.

【 授权许可】

Unknown