The present paper reports on an investigation to monitor the drought status in Algerian forest covered areas with satellite Earth observations because ground data are scarce and hard to collect. The main goal of this study is to map surface energy fluxes with remote sensing data, based on a simplified algorithm to solve the energy balance equation on each data pixel. Cultivated areas, forest cover and a large water surface were included in the investigated surfaces. The input parameters involve remotely sensed data in the visible, near infrared and thermal infrared. The surface energy fluxes are estimated by expressing the partitioning of energy available at the surface between the sensible heat flux (H) and the latent heat flux (LE) through the evaporative fraction (Λ) according to the S-SEBI (Simplified Surface Energy Balance Index) concept. The method is applicable under the assumptions of constant atmospheric conditions and sufficient wet and dry pixels over a Landsat 7 image. The results are analyzed and discussed considering instantaneous latent heat flux at the data acquisition time. The results confirm the relationships between albedo (r₀), the surface temperature (T₀) and the evaporative fraction. The method provides estimates of air temperature and LE close to reference measurements. The estimate of latent heat flux and other variables are comparable to those of previous studies. Their comparison with other methods shows reasonable agreement. This approach has demonstrated its simplicity and the fact that remote sensing data alone is sufficient; it could be very promising in areas where data are scarce and difficult to collect.

The Tlemcen region is characterized by very diverse and steep areas exposed to gravity hazards, especially in high and medium mountain areas. Tlemcen National Park was chosen for this study, the main objective of which is to map fragile areas in close relation to reduced vegetation cover due to land-use changes and forest fires. Multi-source data were used to monitor land use/land cover (LULC)patterns in the study area between 1987 and 2017. The methodology is based on an object-oriented classification of the Landsat images, using the K nearest neighbor method for mapping the major LULC classes at the national park level. The results show that LULC is constantly changing in the study area. In 1987, the landscape was made up of (16.5%) oak forests (holm oak, cork oak, zean oak) and Aleppo pine, which then deteriorated following repeated fires in the nineties to barely represent 7.22% of the surface in 1995, followed by a fast forest reclamation, with the forest area doubling in 10 years (13.46% of the area in 2005), and a near stabilization of the forest cover in 2017 with 14.68% of the area. These mutations are mainly due to fluctuations in anthropogenic action. Despite past declines and disturbances, the current forested area in the Tlemcen area represents significant forest capital classified as a national park to be protected and developed.

Purpose: The objective of this study was to measure the fire risk of forests and to compare areas with high sensitivity to forest fires. Theoretical Framework: Many authors have demonstrated the fragility of Algerian forests in the face of fires (Belhadj, 2003; Souidi et al., 2010 and 2017). In this research paper, the researchers focused on identifying the factors responsible for the risk of forest fires in Algeria using a state-of-the-art tool, the Geographic Information System (GIS). The researchers explained a scientific process for exploring new indicators using GIS, and showed how to develop a forest fire risk map. Design/Methodology/Approach: The elaboration of the fire risk map requires the application of a model set up, and tested on forest areas in the Mediterranean region. The applied model involves the three main factors of forest fire risk assessment: topomorphology, fuel, and human occupation. Findings: According to the results obtained, our study area is dominated by a very high risk index. In addition, more than half of the surface area of our study zone is located in topomorphological conditions that are highly conducive to the multiplication of fires and can increase the risk of forest fires breaking out. This study will help us to better control the risk of fires and to manage fire-fighting operations in the field. Research, Practical & Social Implications: Mapping the risk of forest fires using GIS will help land managers and planners to identify sensitive areas for better preservation and intervention in the event of fire. Originality/Value: The results show that the number of forest fires is increasing over time and that managing them is becoming increasingly difficult. The use of a GIS for all stakeholder and managers will make it possible to combat forest fires.

The present study aims at documenting the use of the medicinal plants by the local populations of five regions in the province of Relizane in the North-West of Algeria. Our findings show that the local populations use 104 species from 46 botanical families. The predominant families are Lamiaceae (12%), Apiaceae (10%), Compositae (8%), and Fabaceae (5%). Moreover, the most frequently cited species are Thymus vulgaris L. (83 citations), Olea oleaster Hoffmanns. & Link (80 citations), Mentha spicata L. (75 citations), and Eucalyptus salmonophloia F.Muell. (71 citations). The highly cited medicinal species may be further investigated through future phytochemical and biological studies.

L'infrastructure verte favorise l'aménagement paysager dans la résilience urbaine afin de renforcer le développement durable. Outre leurs fonctions écologiques, les infrastructures vertes, en tant qu’outil de planification, contribuent aux avantages sociaux et économiques, conduisant à la réalisation de zones urbaines durables, résilientes, inclusives et compétitives. Dans cette revue narrative, nous avons constaté que le concept d’infrastructure verte a passé par plusieurs phases d’évolution d’une mise en place d’un réseau d’espaces verts urbains vers la production de services écosystémiques pour enfin migrer vers des solutions basées sur la nature. Ces infrastructures vertes représentent des outils d’aménagement durable, d’adaptation au changement climatique et de reconquête de la biodiversité.