Land Suitability for Biological Wastewater Treatment in Lebanon and the Litani River Basin Using Fuzzy Logic and Analytical Hierarchy Process

Biological wastewater treatment (BWWT) has been demonstrated to be a suitable procedure to degrade organic pollutants by utilizing natural processes. This paper presents a validated model to map land suitability for BWWT systems under the climatic conditions of Lebanon and the Litani River basin, using the Geographic Information System (GIS) and a machine learning approach for the Litani River Basin and Lebanon. The model was validated using fuzzy theory and the analytic hierarchy process (AHP) modeling theory, and a final suitability map was created in Lebanon that combined potential areas for Biological Wastewater Treatment (BWWT) based on particular criteria. Results show that spatial distribution of the suitable areas for BWWT sites differs for each of the criteria and the total extent of these potential areas is 162.94 km2 all over Lebanon and 42.62 km2 in the Litani basin areas. This area covers around 1.55% of the Lebanese areas and can help more than 30 regions while the total number of beneficiaries can reach a minimum of 60,000 and a maximum of 180,000 which represents between 1.5% and 3.75% of the total population. These potential areas are identified through land suitability classes to sustain the remaining BWWT areas and can contribute to the riparian forest ecosystem and mitigate the impact of climate change

RAINFALL VARIABILITY AND SOIL EROSIVITY IN SEMI-ARID REGIONS: CASE OF THE WESTERN ALGERIAN REGION

Résumé                                                                                                                         Cette étude analyse la variabilité spatiale des précipitations mensuelles à partir de données provenant de 42 stations du bassin versant de Macta sur 41 ans. En se basant sur les relations entre plusieurs variables géographiques et les indices de précipitations. Nous avons estimé l'indice de précipitation (Ip), la concentration de précipitation (PCI), l'indice de Fournier modifié (MFI) et la dégradation spécifique (E). Des tests statistiques multifactoriels ont été utilisés pour évaluer les relations entre différentes variables géographiques et paramètres de précipitation. Les résultats obtenus ont montré des relations significatives de l'ordre de 82%, justifiant la grande hétérogénéité spatiale des variables climatiques dans la zone d'étude. L'analyse multifactorielle a montré des relations significatives entre les variables étudiées en les regroupant avec les mêmes tendances dans les axes factoriels. Nous notons le groupe de longitude-latitude-indice de Fournier et la dégradation spécifique d'un côté, et les précipitations annuelles d'altitude moyenne de l'autre côté. L’altitude et la latitude sont les variables les plus importantes qui régissent la distribution spatiale et la variation des précipitations annuelles et intraannuelles. Cependant, la dégradation des sols est fortement influencée par le régime pluviométrique annuel moyen. L'utilisation des pluies mensuelles nous a permis de surmonter les contraintes d'intensité des précipitations, la relation R-IFM s'est révélée utile, montrant l'importance des pluies moyennes dans l'amplification de l'érosivité. L’altitude et la latitude sont les variables les plus importantes qui régissent la distribution spatiale et la variation des précipitations annuelles et intraannuelles. Cependant, la dégradation des sols est fortement influencée par le régime pluviométrique annuel moyen. L'utilisation des pluies mensuelles nous a permis de surmonter les contraintes d'intensité des précipitations, la relation R-IFM s'est révélée utile, montrant l'importance des pluies moyennes dans l'amplification de l'érosivité. L’altitude et la latitude sont les variables les plus importantes qui régissent la distribution spatiale et la variation des précipitations annuelles et intraannuelles. Cependant, la dégradation des sols est fortement influencée par le régime pluviométrique annuel moyen. L'utilisation des pluies mensuelles nous a permis de surmonter les contraintes d'intensité des précipitations, la relation R-IFM s'est révélée utile, montrant l'importance des pluies moyennes dans l'amplification de l'érosivité.Mots-clés: précipitation, érosivité, analyse multifactorielle, semi-aride, ouest algérie

Land Capability for Agriculture, Hermel District, Lebanon

For the purpose of mapping land capability by United States Department of Agriculture (USDA) criteria, this paper presents a validated model to map land capability at a scale of 1:20,000 using a digital elevation model and the available soil information for Hermel District (525.6 km2) in Lebanon. The model was validated through fieldwork and it indicates a good overall accuracy of 89% and the significance of the model for mapping land capability at a district level. The study shows that 11.5 km2 (2.2%), 284.6 km2 (54.2%), 66.8 km2 (12.7%), 147.9 km2 (28.1%) and 14.9 km2 (2.8%) of the region were categorized in I, II, III, IV, and V land classes respectively. The comparison between the zoning map already produced for Hermel city and the land capability map demonstrates that the land use patterns need to be modified according to identified land capability classes to sustain the remaining productive lands for future generations

Soil scarification favors natural regeneration of Pinus pinea in Lebanon forests: Evidences from field and laboratory experiments

International audiencePinus pinea is an important species for ecological and economic reasons in the Mediterranean area and especially in Lebanon. However, conditions of its natural regeneration have received little attention. Our study aimed to test the influence of soil disturbances, predation and autotoxicity on pine regeneration. A seed sowing field experiment was conducted in a mature stand in which two types of soil disturbances were tested (soil scarification and litter burning) in presence or absence of predation. In addition, a laboratory experiment evaluating the influence of litter (present, absent or burned) and green needle leachates (i.e. in order to mimic potential autotoxicity) on seed germination and seedling growth was conducted. Results showed a strong effect of soil disturbance, in particular soil scarification which promoted seedling emergence and early survival, whereas the role of predation was low. Forty to sixty days after seed installation, seedling density peaked at 14.9 ± 0.4 seedling.m in the scarification treatment, 13.1 ± 0.4 in the burning treatment and 8.4 ± 0.4 in the control treatment. However, an unexpected high mortality rate was recorded at the end of the field experiment in all treatments, as after seven months seedling density dropped to 0.2 ± 0.02. In the laboratory experiment, we emphasized an autotoxic effect of green needle aqueous extract on seed germination and seedling growth in the presence of litter. This allelopathic effect could be potentially linked to the presence of quinic acid which was measured as the major metabolite detected in needle aqueous extracts. In conclusion, we recommend soil preparation treatments to favour seedling emergence in combination with thinning to achieve seedling development on the long term