MONITORING THE EFFECT OF DROUGHTS AND EXTREME CLIMATE VARIABLES FOR VARIOUS TIME PERIODS ON VEGETATION DENSITY IN THE REGHAIA CATCHMENT, ALGERIA

Abstract

Understanding the characteristics of vegetation and its impact on climate change, as well as studying droughts and their causes, is crucial. Based on Modis data, NDVI use, SPEI indicators, and climatic factors, this paper verified the plant index's response to climatic changes and drought in the Reghaia basin during 2000–2022. Based on correlation analysis in different time periods, allows analysis of the causes of changes. Results showed a decline in the vegetation index in both seasonal and annual periods, with spatial distributions showing that about 60% of the vegetation area had NDVI values below 0.35, and the summer had a greater share of vegetation degradation. Ranges showed a negative relationship between NDVI and climatic factors with a delay of 1-2 months. The drought rate increased in varying proportions, and SPEI's trend was negative, especially in summer and autumn (- 00539/a, R2 = 0.3401), and (-00231/a, R2 = 0.1217) respectively, and SPEI reached its lowest levels in 2022, the peak of NDVI fell with the SPEI index. In recent years, the drought has intensified and the water level has decreased. Finally, climate change has a negative impact on the increase in droughts and plants.

Keywords

• droughts
• vegetation density
• climate factors
• ndvi