Remote Sensing Assessment Of Pastoral Plantation Efficiency In Combating Desertification: Analysis Of NDVI Evolution, Rainfall Correlation And Pastoral Management Impact In Djelfa Steppe (2005-2025)

Abstract

The steppe ecosystems of Djelfa province are experiencing critical environmental degradation of their vegetation biomass, compromising essential ecosystem services including water regulation, carbon sequestration, and biodiversity conservation. This deterioration results from complex interactions between anthropogenic factors (overgrazing, unsustainable resource exploitation) and climatic disturbances (rainfall variability, warming, extreme events). Since 2005, the High Commission for Steppe Development (HCDS) has implemented an integrated ecological restoration approach across 20 million hectares of steppe ecosystems. Pastoral plantations constitute the priority intervention, designed as nature-based solutions to mitigate land degradation and promote adaptation to environmental changes.

The case study covers the period 2005-2025 and exploits GPS coordinates of areas planted by the HCDS in 2005, according to data provided by technical services and available synoptic sheets. Of the 16 projects identified, five projects were selected in potential areas with optimal characteristics for this research.

This study develops an advanced remote sensing assessment approach, integrating multitemporal analysis of the Normalized Difference Vegetation Index (NDVI) over two decades (2005-2025), exploitation of LandTrend satellite data, quantification of environmental trajectories of restored ecosystems, and establishment of correlations between vegetation dynamics and hydroclimatic variability. The methodology enables continuous monitoring of key ecological indicators (vegetation index, vegetation cover, primary productivity), near real-time surveillance of degradation/restoration processes, early detection of areas at high environmental risk, and objective evaluation of ecological management performance.

The analyses reveal the critical importance of adaptive management in maintaining the environmental integrity of steppe formations. NDVI spectral signatures accurately identify regeneration/exploitation cycles, critical thresholds beyond which ecological recovery capacity is compromised, zones of optimal resilience to recurrent climatic stress, and sectors requiring urgent environmental interventions. This pioneering research, integrating high-resolution remote sensing, hydroclimatic data, and landscape ecology, constitutes a methodological framework for evaluating ecological restoration programs. It provides innovative tools to optimize the sustainability of anti-desertification interventions and strengthen the environmental resilience of steppe ecosystems facing global climate change challenges. The recommendations aim to improve the efficiency of future strategies and contribute significantly to environmental sciences applied to sustainable management of Mediterranean semi-arid ecosystems.