Natural Resources and Sustainable Development (May 2023)

A DIACHRONIC STUDY OF THE GREEN DAM DYNAMICS BY SPACE TELEDETECTION: SEMI-ARID ZONE OF DJELFA, ALGERIA

  • Khaouani Boumediene,
  • Berrabah Djamal Edine,
  • Bouarfa Said,
  • Hadbaoui Ilyes

DOI
https://doi.org/10.31924/nrsd.v13i1.123
Journal volume & issue
Vol. 13, no. 1
pp. 137 – 146

Abstract

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In this study, teledetection data is used to examine the state of the Green Belt Forest cover and its evolution in the Djelfa region from 1972 to 2021. Landsat Satellite images MMS 1972, TM 1987, 2003, 2007, and Landsat Oli 2021 were selected for the analysis. Forest zones and ecological balance were determined for 1972, 1987, 2003, 2007, and 2021 using supervised classification and ground investigations. According to the findings, the occupied area in 1972 was 67461.17 ha, accounting for 4.51 % of the total. Green Belt surface in the department of Djelfa was 8.6 2% in 1987, 4.7 % in 2003, and 5.5 % in 2007. Pine trees accounted for 5.74 % of the total Green Belt surface in the study zone in 2021. The degradation degree revealed variable changes in the semi-arid zone forests studied. In 1987, the ecological balance of forest cover was generally positive, with a 47.74 % rate, and in 2003, the regression was around 45.05 % compared to 1987. Between 2007 and 2021, there was a slight increase of 27.33 %. The increased forest cover visible in the satellite image reflected the spread of tree plantations completed in the 1980s, as part of the Green Belt project and the appropriate climate conditions during these years. As a result, re-launching the Green Belt mega tree planting project in 2007 and 2021 resulted in increased surface forest cover. The classified sequence satellite images were used to estimate surface loss between 1987 and 2021, resulting in the disappearance of 33.43 % of the forest. The degradation of the Green Belt between 1987 and 2021 is due to various factors, the two most significant of which are the national army's withdrawal from the Green Belt reforestation project and increased drought frequency. The methodology used in this study produced a base map that can be used as a management tool to better protect the ecosystem dynamic.

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