Mediterra 2016 : Zéro gaspillage en Méditerranée, 2016
Resume Ce chapitre examine l’etat des ressources en terres dans le bassin mediterraneen, en parti... more Resume Ce chapitre examine l’etat des ressources en terres dans le bassin mediterraneen, en particulier en Afrique du Nord et au Moyen-Orient. La rarete du capital naturel, les options limitees d’extension des cultures et les menaces de changement climatique pouvant aggraver la dependance de la region aux importations de produits agricoles, la gestion durable des sols devient des lors un enjeu strategique. La region se doit de preserver ses terres productives et de mettre en œuvre des politiques qui reglementent leur utilisation, fondees sur leur potentiel biophysique, social et economique, et axees sur les besoins des agriculteurs. Afin de renverser la tendance actuelle de degradation des sols et de limiter la perte de terres arables, les decideurs politiques des differents echelons doivent pouvoir s’appuyer sur un plan d’action qui propose des solutions applicables.
A significant increase in forest areas has been observed in the last decades in Europe due to the... more A significant increase in forest areas has been observed in the last decades in Europe due to the abandonment of agricultural activities but also thanks to the implementation of reforestation/afforestation projects. These changes in land use have consequences in soil processes (e.g. erosion rates, accumulation of organic matter, humification, leaching, podzolisation), water and nutrient cycle, or productivity, amongst others. This new situation deserves an analysis of the causes and consequences in different scenarios, as the advantages and disadvantages of land abandonment can be different according to particular circumstances. In ordinary local soil surveys, some of the most widely used indicators to evaluate soil changes are organic carbon, nutrients and pH. Variations of these key soil properties can also be used to evaluate the consequences of land abandonment.
ABSTRACT Desertification caused by land degradation and overexploitation of natural resources is ... more ABSTRACT Desertification caused by land degradation and overexploitation of natural resources is threatening large parts of eastern and southern Mediterranean. The actual state of desertification sensitivity in Lebanon was spatially assessed using site specific environmental bio-physical indicators, demographic pressure and socioeconomic conditions. Bio-physical assessment included the aridity index derived from integrated assessment of the historical data for 48 climatic stations spread throughout the country, the new detailed soil map at 1:50,000 scale, and the updated land cover/use map at 1:20,000 derived from IKONOS 2005. The methodology also included livelihood conditions and poverty at local administrative “Caza” level. Results showed the integrated impact of local climate, soil and vegetation quality and socioeconomic conditions on sensitivity to desertification. A total of 78% of the territories have low and very low climate quality index preconditioning the sensitivity to desertification. Fourteen Cazas out of 26 in total, representing more than 66% of the country, have low socioeconomic satisfaction index. Furthermore, negative trends are alleviated by good quality relict soils and vegetation cover. The actual extent of desertification covers 40.48% of the national territory, much of which occurs under semi-arid climate, moderate or low soil and vegetation quality and poor living conditions. The outcome of this research adjusted the previous coarse estimates of desertification prone areas at the national level. Results allow for realistic, policy oriented local assessment for responsive land use planning and proactive sustainable, national and local land management in the context of the national action plan to combat desertification.
We analysed the hydrological behaviour of a wadi basin in Egypt, whose channel was modified into ... more We analysed the hydrological behaviour of a wadi basin in Egypt, whose channel was modified into levelled terraces for cultivation. A yearly data set was used, consisting of weather data, distributed water content measurements in the terraces of the wadi channel, and run‐off discharges at the wadi outlet. A modelling approach combining a run‐off model and an agro‐hydrological model was tested to simulate, respectively, the water stored in the wadi stream bed after a single rainfall event and the depletion of the stored water by evapotranspiration in the period between two subsequent rainfall events. Calibration and validation of the run‐off model were based on both basin outlet run‐off and distributed water storage measurements. High Nash–Sutcliffe efficiencies were obtained for both distributed channel water storage and outlet discharges, showing the importance of having available distributed storage measurements, besides basin outlet discharges, to obtain more robust model predictions. The soil–plant–atmosphere model was not calibrated as the parameters for the hydraulic properties, all coming from direct measurements, proved to describe effectively the distributed water storages measured in the terraces during the monitoring campaign. It was observed that the terraces (about 100,000 m3) may store up to 50,000 m3 of water. By considering that in the soil considered, the water content at the wilting point is about 5% and that in July, the soil profile is still able to retain about 40% of the initial volume, most of the water stored may be used by crops for the whole spring–summer period.
Mediterra 2016 : Zéro gaspillage en Méditerranée, 2016
Resume Ce chapitre examine l’etat des ressources en terres dans le bassin mediterraneen, en parti... more Resume Ce chapitre examine l’etat des ressources en terres dans le bassin mediterraneen, en particulier en Afrique du Nord et au Moyen-Orient. La rarete du capital naturel, les options limitees d’extension des cultures et les menaces de changement climatique pouvant aggraver la dependance de la region aux importations de produits agricoles, la gestion durable des sols devient des lors un enjeu strategique. La region se doit de preserver ses terres productives et de mettre en œuvre des politiques qui reglementent leur utilisation, fondees sur leur potentiel biophysique, social et economique, et axees sur les besoins des agriculteurs. Afin de renverser la tendance actuelle de degradation des sols et de limiter la perte de terres arables, les decideurs politiques des differents echelons doivent pouvoir s’appuyer sur un plan d’action qui propose des solutions applicables.
A significant increase in forest areas has been observed in the last decades in Europe due to the... more A significant increase in forest areas has been observed in the last decades in Europe due to the abandonment of agricultural activities but also thanks to the implementation of reforestation/afforestation projects. These changes in land use have consequences in soil processes (e.g. erosion rates, accumulation of organic matter, humification, leaching, podzolisation), water and nutrient cycle, or productivity, amongst others. This new situation deserves an analysis of the causes and consequences in different scenarios, as the advantages and disadvantages of land abandonment can be different according to particular circumstances. In ordinary local soil surveys, some of the most widely used indicators to evaluate soil changes are organic carbon, nutrients and pH. Variations of these key soil properties can also be used to evaluate the consequences of land abandonment.
ABSTRACT Desertification caused by land degradation and overexploitation of natural resources is ... more ABSTRACT Desertification caused by land degradation and overexploitation of natural resources is threatening large parts of eastern and southern Mediterranean. The actual state of desertification sensitivity in Lebanon was spatially assessed using site specific environmental bio-physical indicators, demographic pressure and socioeconomic conditions. Bio-physical assessment included the aridity index derived from integrated assessment of the historical data for 48 climatic stations spread throughout the country, the new detailed soil map at 1:50,000 scale, and the updated land cover/use map at 1:20,000 derived from IKONOS 2005. The methodology also included livelihood conditions and poverty at local administrative “Caza” level. Results showed the integrated impact of local climate, soil and vegetation quality and socioeconomic conditions on sensitivity to desertification. A total of 78% of the territories have low and very low climate quality index preconditioning the sensitivity to desertification. Fourteen Cazas out of 26 in total, representing more than 66% of the country, have low socioeconomic satisfaction index. Furthermore, negative trends are alleviated by good quality relict soils and vegetation cover. The actual extent of desertification covers 40.48% of the national territory, much of which occurs under semi-arid climate, moderate or low soil and vegetation quality and poor living conditions. The outcome of this research adjusted the previous coarse estimates of desertification prone areas at the national level. Results allow for realistic, policy oriented local assessment for responsive land use planning and proactive sustainable, national and local land management in the context of the national action plan to combat desertification.
We analysed the hydrological behaviour of a wadi basin in Egypt, whose channel was modified into ... more We analysed the hydrological behaviour of a wadi basin in Egypt, whose channel was modified into levelled terraces for cultivation. A yearly data set was used, consisting of weather data, distributed water content measurements in the terraces of the wadi channel, and run‐off discharges at the wadi outlet. A modelling approach combining a run‐off model and an agro‐hydrological model was tested to simulate, respectively, the water stored in the wadi stream bed after a single rainfall event and the depletion of the stored water by evapotranspiration in the period between two subsequent rainfall events. Calibration and validation of the run‐off model were based on both basin outlet run‐off and distributed water storage measurements. High Nash–Sutcliffe efficiencies were obtained for both distributed channel water storage and outlet discharges, showing the importance of having available distributed storage measurements, besides basin outlet discharges, to obtain more robust model predictions. The soil–plant–atmosphere model was not calibrated as the parameters for the hydraulic properties, all coming from direct measurements, proved to describe effectively the distributed water storages measured in the terraces during the monitoring campaign. It was observed that the terraces (about 100,000 m3) may store up to 50,000 m3 of water. By considering that in the soil considered, the water content at the wilting point is about 5% and that in July, the soil profile is still able to retain about 40% of the initial volume, most of the water stored may be used by crops for the whole spring–summer period.
Through this assessment, the authors and the United Nations Environment Programme (UNEP) secretar... more Through this assessment, the authors and the United Nations Environment Programme (UNEP) secretariat are providing an objective evaluation and analysis of the pan-European environment designed to support environmental decision-making at multiple scales. In this assessment, the judgement of experts is applied to existing knowledge to provide scientifically credible answers to policy-relevant questions. These questions include, but are not limited to the following: • What is happening to the environment in the pan-European region and why? • What are the consequences for the environment and the human population in the pan-European region? • What is being done and how effective is it? • What are the prospects for the environment in the future? • What actions could be taken to achieve a more sustainable future?
Uploads
Papers by Pandi Zdruli
• What is happening to the environment in the pan-European region and why?
• What are the consequences for the environment and the human population in the pan-European region?
• What is being done and how effective is it?
• What are the prospects for the environment in the future?
• What actions could be taken to achieve a more sustainable future?