Desertification assessment and future scenarios in the context of the climate change influence in Lebanon: planning for restoration activities and hydrological modeling

The purpose of this study was to assess desertification and to study the effects of land use change and climate change on hydrological variables in El Asi-Orontes watershed (Lebanon). This work presents a validated model to map land capability at a scale of 1:20,000 for El-Hermel District (Lebanon). The model was validated through field work and it indicates a good overall accuracy of 89%. The comparison between the zoning map already produced for the area of influence of Hermel city and the land capability map demonstrates a high risk of desertification because the zoning map doesn’t respect the capability of lands. We have also applied a hydrological model (WiMMed) in the study region in 2005 and 2013 to describe how land use change would affect the hydrological parameters. This study found that the land use change from 2005 to 2013 has negative effects on the hydrological characteristics of this watershed decreasing the infiltration capacity and the soil moisture of second layer in this area. Based on the results of the simulations, it can be concluded that in term of runoff low differences was registered in all seasons between 2005 and 2013. An attempt has been made to compare the current hydrological variables of the study area (infiltration, run-off, soil moisture of second layer) to the simulated variables in 2050 under 2 RCP future scenarios, RCP 2.6 and RCP8.5, assuming that that the future land use is the same as the current land use (2013 land use/land cover map). Under same land use conditions, a rise of temperature accompanied with a decrease of precipitation will result in a decrease of infiltration, soil moisture of second layer in all seasons, and run-off during spring and winter. All the hydrological variables within the study area are expected to have further decreases under RCP 8.5 compared to RCP2.6 for all seasons. However, the influence of land use change on soil moisture of second layer is much more significant when compared to climate variability and climate change. In conclusion, the land use patterns of the study region need to be modified according to identified land capability classes to sustain the remaining productive lands for future generations. This work was helpful to assess the stress on the land and hydrological states of the study region under different climatic scenarios, but to suggest restoration activities and to reduce the negative effects of land use change and climate change, more detailed studies are needed to suggest the correct land use type and to find a way to mitigate the effects of climate change in El Asi-Orontes watershed specifically, and semi-arid areas generally.El objetivo de esta tesis ha sido evaluar la desertificación y estudiar los efectos del cambio de uso de la tierra y el cambio climático en las variables hidrológicas de la cuenca de El Asi- Orontes (Líbano). En este trabajo se presenta un modelo validado para cartografiar la capacidad y aptitud de uso de la tierra, a una escala de 1:20.000, para el distrito de Hermel (Líbano). El modelo fue validado a través del trabajo de campo, mostrando una buena precisión general del 89%. La comparación entre el mapa de zonificación ya elaborado para el área de influencia de la ciudad de Hermel y el mapa de capacidad y aptitud de uso de la tierra demuestra un alto riesgo de desertificación ya que la planificación territorial de Hermel no está considerando el potencial y la capacidad de uso de la tierra. También se ha aplicado un modelo hidrológico (WiMMed) en la región de estudio en 2005 y 2013, para describir cómo el cambio de uso de la tierra ha afectado a los parámetros hidrológicos que definen la dinámica de la cuenca de El Asi-Orontes. Este estudio encontró que el cambio de uso de la tierra entre 2005 y 2013 tuvo efectos negativos sobre las características hidrológicas de esta cuenca disminuyendo la capacidad de infiltración y la humedad del suelo de la segunda capa en esta área. Con base en los resultados de las simulaciones, se puede concluir que en términos de escorrentía se registraron bajas diferencias en todas las estaciones entre 2005 y 2013. También se han comparado las variables hidrológicas actuales del área de estudio (infiltración, escorrentía, humedad del suelo de la segunda capa) con las variables simuladas en 2050 bajo 2 escenarios futuros, RCP 2.6 y RCP8.5, asumiendo que el uso futuro de la tierra es el mismo que el uso actual de la tierra (mapa de uso/cobertura de la tierra de 2013). Bajo las mismas condiciones de uso de la tierra, un aumento de la temperatura acompañado de una disminución de las precipitaciones resultará en una disminución de la infiltración, de la humedad del suelo de la segunda capa en todas las estaciones, y de la escorrentía durante la primavera y el invierno. Se espera que todas las variables hidrológicas dentro del área de estudio tengan disminuciones mayores bajo el escenario RCP8.5 en comparación con el RCP2.6 para todas las estaciones. Sin embargo, la influencia del cambio de uso de la tierra en la humedad del suelo de la segunda capa es mucho más significativa en comparación con la variabilidad y el cambio climático. En conclusión, los patrones de uso de la tierra de la región de estudio necesitan ser modificados de acuerdo a las clases de capacidad y aptitud de uso de la tierra identificadas para mantener las tierras productivas restantes para las generaciones futuras. Este trabajo fue útil para evaluar la presión ejercida sobre la tierra en relación a sus usos y los estados hidrológicos de la región de estudio bajo diferentes escenarios climáticos, pero para planificar actividades de restauración adecuadas y reducir los efectos negativos del cambio en el uso de la tierra y el cambio climático, se necesitan estudios más detallados para sugerir el tipo correcto de uso de la tierra y encontrar una manera de mitigar los efectos del cambio climático en la cuenca hidrográfica de El Asi-Orontes específicamente, y en las áreas semiáridas en general

Regional Landsat-Based Drought Monitoring from 1982 to 2014

Drought is a serious natural hazard with far-reaching impacts including soil damages, economic losses, and threatening the livelihood and health of local residents. The goal of the present work was to monitor the vegetation health across Lebanon in 2014 using remote sensing techniques. Landsat images datasets, with a spatial resolution of 30 m and from different platforms, were used to identify the VCI (Vegetation Condition Index) and TCI (Temperature Condition Index). The VCI was based on the Normalized Difference Vegetation Index (NDVI) datasets. The TCI used land surface temperature (LST) datasets. As a result, the VHI (Vegetation Health Index) was produced and classified into five categories: extreme, severe, moderate, mild, and no drought. The results show practically no extreme drought (~0.27 km2) in the vegetated area in Lebanon during 2014. Moderate to severe drought mainly occurred in the north of Lebanon (i.e., the Amioun region and the plain of Akkar). The Tyr region and the Bekaa valley experienced a low level of drought (mild drought). This approach allows decision makers to monitor, investigate and resolve drought conditions more effectively

Malva pseudolavatera Leaf Extract Promotes ROS Induction Leading to Apoptosis in Acute Myeloid Leukemia Cells In Vitro

Malva pseudolavatera Webb & Berthel. is a plant from the Malvaceae family that has long been included in the human diet due to its various curative effects. Many plant leaf extracts from the various species of Malva genus have been reported to possess anti-cancer properties, however, studies on M. pseudolavatera Webb & Berthel. leaves have documented anti-inflammatory and anti-oxidant effects with no emphasis on their possible anti-cancer potential. The present study explores the anti-cancer properties of Malva pseudolavatera Webb & Berthel. leaf extract on acute myeloid leukemia (AML) cell lines in vitro and deciphers the underlying molecular mechanism. Treatment of AML cell lines with M. pseudolavatera methanolic leaf extract showed a dose- and time-dependent inhibition of proliferation and a dose-dependent increase in apoptotic hallmarks such as an increase in phosphatidylserine on the outer membrane leaflet and membrane leakage in addition to DNA fragmentation. The pro-apoptotic effect was induced by reactive oxygen species (ROS) as well as an upregulation of cleaved poly(ADP-ribose) polymerase (PARP), increase in Bax/Bcl-2 ratio, andrelease of cytochrome-c from the mitochondria. Major compounds of the extract included methyl linolenate, phytol, gamma-sitosterol, and stigmasterol as revealed by gas chromatography coupled with mass spectrometry, and amino acids, amino acid derivatives, tiliroside, 13-hydroxyperoxyoctadecadienoic, and quercitrin as detected by liquid chromatography coupled to mass spectrometry

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