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The mount Cameroon region is experiencing rapid and continuous changes mainly due to anthropogenic influences (wood extraction and agricultural extension). The changes occur at varying spatial scales most often not more than 250 m for small scale farms and extraction of fuelwood; extending to hundreds of hectares for plantation agriculture and commercial logging. Given the importance of land use and land cover data in conservation planning, accurate and efficient techniques to provide up-to-date data are required. Techniques based on multi-temporal, multi-spectral, satellite-sensor-acquired data have demonstrated great potential as a means to detect, identify, map and monitor forest cover and forest cover changes irrespective of their causal agents. Nevertheless variable opinions still exist about the value and appropriateness of these techniques due to landscape complexities of study areas and data used. Moreover, forest cover change is a location specific problem with the effect, pattern and magnitude of identified drivers not just differing from country to country but also from one region to another. Consequently, it is absolutely necessary to devise techniques that empirically determine the extent and identify the magnitude at which factors identified, influence the continuous changes in forest cover patterns. Furthermore, given that many different factors influence changes in forest cover and that these factors operate at different levels, mixing up the factors of various levels generally leads to a wrong specification of the causal relationships between variables. It is thus of utmost importance to understand the role of each of these factors on forest cover change. The thesis summarises the methods and results of applying different thematic information extraction algorithms as well as different change detection algorithms to monitor forest cover and forest cover change in the mount Cameroon region. Furthermore, the study sought to explain the forest cover changes detected using spatial geophysical variables extracted from available remote sensing and GIS data. The research mainly focuses on determining, suitable techniques for monitoring forest cover within the difficult Cameroonian context - lack of decent soft- and hardware, unavailability of satellite imagery, lack of personnel etc. Bi-temporal Landsat imagery (Landsat TM 1987 and ETM+ 2002) coupled with ancillary GIS data were employed to pursue the objectives shortlisted. The scenes were geometrically and radiometrically corrected and the time series co-registered to avoid erroneous changes. They were subsequently enhanced spectrally and spatially to obtain ancillary information pertaining to forest cover distribution. The supervised pixel-based classification using Maximum Likelihood Classifier (MLC) and the Nearest Neighbour (NN) object-based classification were implemented to map the tropical forests of the mount Cameroon. The efficacy of both approaches was assessed based on the accuracy of the respective thematic maps and a visual evaluation of the delineation of land cover/use categories. Five change detection procedures were also tested to determine their effectiveness in detecting and delineating forest cover changes. The following techniques were implemented: univariate image differencing using bands 4 and 5, transformed band differencing (NDVI), post classification comparison, change vector analysis using tasseled cap as biophysical parameter and multi date change detection using binary mask (analysis of differencing in classification results). The accuracy of the resultant change maps was assessed based on information procured during field study. The algorithms were compared based on their ability to identify quantitative and qualitative changes. Moreover, aspects like ease of implementation of technique and interpretability of results were also taken into consideration – important considerations for transferring remote sensing technology to local and international governmental and non-governmental organisations as well as being a sustainability requirement for community forest management initiatives. Finally, univariate statistical models were developed to understand the effect of certain spatial variables on forest cover change. Nearness to roads, nearness to watersheds, nearness to settlement, aspect, slope and soil types were extracted from available remote sensing and GIS data and implemented in this study. The implementation of the object oriented approach did not lead to substantial improvements in the results. On the contrary, the pixel-based technique had slightly better overall accuracy results than the object-oriented approach (89.39 % as against 87.12 %). Nevertheless the strength of the object-oriented approach in classifying heterogeneous land cover categories was confirmed. The highest overall accuracy from a single change detection technique was achieved with the band 5 differencing 89.6 %. Post classification comparison also produced substantially good results (89.4 %), with a Kappa coefficient better than that of the Band 5 differencing (0.86 against 0.79). The other techniques produced modest results with overall accuracies of 72.7 %, 70.1 %, and 61 % for the NDVI differencing, CVA and Band 4 differencing respectively. Nevertheless, each algorithm has its own merits with respect to facility of implementation, information content and interpretability of results. The high complementarity between different change detection methods makes it possible to combine algorithms and improve efficacy in detecting changes. The hybrid approach (multidate change detection procedure using binary mask) produced optimal qualitative and quantitive results – providing "from-to" information as well as high location accuracy of change areas. Despite requiring a number of steps (hybrid method), it reduces change detection errors and provides "from-to" change classification information. The efficacy of the method depends on the "change/no-change" binary mask. Nearness to road proved to be the most influencial factor on forest cover change followed by nearness to settlement and slope. Nearness to watersheds had an insignificant effect on the changes while the variables aspect, soil type had no effect on forest cover change. Nevertheless, it was proven that the spatial variables implemented in this work failed to interpret the change of forest land to industrial plantations therefore suggesting the implementation of other socio-economic and political variables to better explain their occurrence. ; Die Studie folgt den Bemühungen Wissenschaftler aus aller Welt, die tropischen Ökosysteme zu schützen und somit die globalen Klimaänderungen abzumildern. In diesem Zusammenhang wurden zahlreiche Versuche unternommen, die tropischen Wälder auf globaler Ebene zu kartieren. Heutzutage versucht man zusätzlich auf regionaler Ebene zu agieren. Im Rahmen der vorliegenden Arbeit wurde analysiert, inwiefern der Einsatz hochauflösender Satellitendaten und Bildinterpretations-Algorithmen die Deutung der kontinuierlichen Waldveränderungen am Mount Kamerun verbessern kann. Im Forstsektor mit mangelnden Informationen über den Zustand der Wälder, kann die Anwendung von Fernerkundungstechnologien die Grundlage eine effektivere Bewirtschaftung gewährleisten. Robuste und leistungsfähige Interpretations-Algorithmen wurden mit dem Beginn der Satellitenerdüberwachung entwickelt. Die Algorithmen ermöglichen, die Flächen der Landbedeckungskategorien nach Ähnlichkeit zu unterscheiden. Es wurden daher verschiedene Algorithmen entwickelt um Vegetation zu kartieren und zu analysieren. Der Einsatz dieser Algorithmen führte zu unterschiedlichen Ergebnissen, weshalb verschiedene Meinungen über den Wert und die Effektivität der jeweiligen Algorithmen bestehen. Im Zusammenhang mit dieser Forschungsarbeit wurden Fernerkundungs- und GIS-Daten sowie erhobene terrestrische Daten evaluiert, um eine quantitative und qualitative Einschätzung von klein- und großräumigen Waldveränderungen des Mount Kamerun zu erfassen. Dabei standen die kleinräumigen Veränderungen im Vordergrund. Es wurde analysiert, inwiefern diese Veränderungen mit verschiedenen Bildinterpretations-Algorithmen sichtbar gemacht werden können. Heutzutage erfordert nachhaltige Waldbewirtschaftung genaue Ressourcen-Daten, die kontinuierlich aktualisiert werden müssen. Leider fehlen solche Informationen im kamerunschen Forstsektor. Präzise Informationen über das Ausmaß der Walddegradierung können über Luftbilder festgestellt werden. Die Kosten der notwendigen wiederholten Erfassung sind jedoch sehr hoch. Außerdem haben Luftbilder in Kamerun einen restriktiven Status und sind sehr schwer Zugänglich. Vor diesem Hintergrund muss das Potential anderer Formen der Fernerkundungsdaten und Techniken sondiert werden. Das Hauptziel der aktuellen Forschung war die Ermittlung der besten Konstellation von Klassifikationsvariablen zur Feststellung, Abgrenzung und Kartierung der Waldflächen sowie deren Veränderungen in den letzten zwei Jahrzehnten durch den Einsatz von multi-temporären Landsat TM und ETM Satellitendaten. Testen von verschiedenen Klassifikationsvariablen, um die vorhandene Vegetationsklassifikation zu verbessern, Einsetzung von Änderungs-Detektion Techniken, um Waldveränderungen besser zu kartieren, Entwicklung von Veränderungsmodellen anhand von Indizien aus Fernerkundung- und GIS-Techniken, um die Veränderungen ausreichend zu verstehen und zu erklären, Bestimmung möglicher Waldveränderungsflächen Die folgenden Fragen wurden beantwortet: Stellt der Einsatz von objekt-basierter Klassifizierung eine wesentliche Verbesserung der Waldklassifikation im Gegensatz zur pixel-basierten Technik dar? Ist das Vergleich nach Klassifizierungs-Verfahren optimal, um Waldflächenveränderungen feststellen zu können? Welche Zusammenhänge bestehen zwischen Waldflächenveränderungen und räumlichen Faktoren wie die Entfernung zu Straßen, Entfernung zu Gewässern, Entfernung zu Siedlungen, Hangneigung, Aspekt und Bodentypen? DAS UNTERSUCHUNGSGEBIET Das Untersuchungsgebiet liegt südwestlich des Mount Kamerun und grenzt an den Atlantik. Die Vegetation besteht aus tropischem Regenwald, montaner und submontaner Vegetation. Landnutzungstypen sind prinzipiell kleinräumige Agrarfelder (Banane, Mais usw.) und großräumige Plantagen (Kakao und Palmen). Die Temperatur liegt im Jahresdurchschnitt zwischen 28° C und 33° C und die Luftfeuchtigkeit beträgt über 70 %. Der Niederschlag ist mit 10 000 mm jährlich sehr hoch. MATERIAL UND METHODE Bei der Untersuchung wurden Landsat TM und ETM Bilder eingesetzt. Das TM Bild wurde am 18.03.1987 erfasst, während das ETM am 30.01.2002 erfasst wurde. Zusätzliche Materialien: Topografische Karte (Russian Quandrangle) 1:500 000 mit 50 m Höhenlinien (bestellt von East View Cartographic), Digitale topografische Karte (Buea/Douala index) – 20 m Auflösung mit 40 m Höhenlinien, Alte Landnutzungs- und Landbedeckungs-Karten. Bodenkarte Kameruns 1:1 000 000 (bestellt von East View Cartographic). In Bezug auf die beschriebenen Ziele, lässt sich die Methodik in drei Teile gliedern: erstens das Testen von verschiedenen Klassifikationsvariablen, um die Klassifikation der Vegetation zu verbessern; zweitens der Einsatz von verschiedenen Änderungs-Detektion Algorithmen, um Waldflächenveränderung festzustellen; drittens die Erstellung eines Univariat-Modells, um den Verlauf der Waldflächenveränderung zu interpretieren. Zu Interpretation von Satellitenbildern werden sogenannte "Ground Truth" Informationen, die durch terrestrische Aufnahmen erhoben werden, benötigt. Die terrestrischen Aufnahmen erfolgten in zwei Phasen: zunächst erfolgte eine Pilotstudie im Dezember 2003, gefolgt von einer Studie von Dezember 2004 bis Februar 2005, in welcher die hier verwendeten Daten erhoben wurden. Punkte aus Wege-Kreuzungen wurden erhoben um die Geometrie der Bilder zu rektifizieren. Zusätzliche Punkte wurden auf allen verschiedenen Landbedeckungskategorien des Gebiets erfasst, um "Training" und "Accuracy Assessment" Datensätze zu erstellen. Ein Klassifikationsschema wurde anhand der terrestrischen Daten erarbeitet. Die folgenden Landbedeckungs-Kategorien wurden betrachtet: "mature secondary forest, young secondary forest, mono-dominant forest, mid-elevation forest, bare ground, forest regrowth". Für die Veränderungsanalyse wurden Flächen, die später entstanden sind, gemessen und die terrestrische Messung wurde als Basis für die Beurteilung der verschiedenen Änderungs-Detektion Algorithmen verwendet. Zusätzliche Daten in Bezug zur Waldveränderung wurden durch Interviews manche Dorfbewohner erfasst. Vor der Interpretation der Bilder wurden sie vorprozessiert, indem die Geometrie korrigiert wurde. Der Einfluss der Topographie auf die digitalen Werte auf Grund von Sonnenwinkeln wurde mit dem C-Faktor-Algorithmus korrigiert. Ein DGM wurde erstellt, nachdem die Höhelinien der topographischen Karte extrahiert und interpoliert wurden. Das DGM wurde für die topographische Korrektur angewendet. Verschiedene räumliche und spektrale Techniken wurden angewandt, um zusätzliche Informationen aus den Bildern zu gewinnen. Das hochauflösende panchromatische Band des Landsat ETM-Bildes wurde mit den spektralen Kanälen der ETM-Daten fusioniert, um zusätzliche Informationen zu erhalten. Das objekt-basierte Verfahren mit der Erstellung von Segmenten und der Kategorisierung der Segmente anhand des "Nearest Neighbour"-Algorithmus sowie das pixel-basierte Verfahren mit dem Einsatz des "Maximum Likelihood"-Algorithmus für die Klassifizierung der Pixels wurden für die Kartierung der Landbedeckung des Mount Kamerun Gebiets eingesetzt. Die Genauigkeit der beiden Verfahren wurde anhand einer "Error Matrix" überprüft (Klassifizierte Punkte wurden mit Terrestrischen Daten gekreuzt). Die Gesamtgenauigkeit, der Kappa Koeffizient so wie die Ersteller- und Benutzer-Genauigkeiten wurden ermittelt. Fünf verschiedene Änderungs-Detektion Verfahren wurden angewendet, um die Waldflächenveränderungen festzustellen. (Band-Differenzierung mit Kanälen 4 und 5, NDVI-Differenzierung, Change Vector Analysis, Vergleich nach Klassifikation und Vergleich nach Klassifikation mit einer binären Maske auf dem zweiten Bild). Die Verfahren wurden nach folgenden Kriterien verglichen: Lage der Veränderung, Typ und Natur der Veränderung, Einsetzbarkeit des Verfahrens und Interpretierbarkeit der Ergebnisse. Ein räumliches Univariat-Modell wurde entwickelt, um den Zusammenhang zwischen den Veränderungsflächen und einigen räumlichen Faktoren zu erklären. Die folgenden räumlichen Faktoren wurden betrachtet: - Entfernung zu Straßen - Entfernung zu Gewässern (Flüsse, Bäche, Seen) - Entfernung zu Siedlungen - Hangneigung und Aspekt - Bodentypen ERGEBNISSE UND SCHLUSSFOLGERUNG Multi-temporäre und multi-spektrale Bilder können eingesetzt werden um die Waldflächenveränderung im Mount Kamerun Gebiet zu überwachen und festzustellen. Die beiden Klassifikations-Verfahren, das objekt-basierte und das pixel-basierte Verfahren haben gute Ergebnisse für die Klassifizierung der Landschaft geliefert. Das pixel-basierte Verfahren hat das Gebiet mit einer Gesamtgenauigkeit von 89,36 % kartiert, während das objekt-basierte Verfahren das Areal mit einer Gesamtgenauigkeit von 87,12 % kartiert. Die Kappa Koeffizienten betragen jeweils 0,86 und 0,83 für das pixel- bzw. das objekt-basierte Verfahren. Die objekt-basierte Klassifizierung führte nicht unbedingt zu einer Verbesserung der Vegetationskartierung. Es eignet sich besser bei der Kartierung von heterogenen Flächen, als das pixel-basierte Verfahren. Dass die meisten "ground truth points" aus homogenen Flächen aufgenommen wurden und die mäßige räumliche Auflösung des Landsatbildes, waren natürlich einen Vorteil für das pixel-basierte Verfahren. Die hauptsächlichen Waldveränderungen in Mount Kamerun Gebiet – Umwandlung von Wäldern zu Agrarfeldern - konnten beobachtet werden und wurden mit großen Präzision mit Hilfe einfacher Fernerkundungstechniken gekennzeichnet. Dies gewinnt, angesichts der Schwierigkeit, die Wälder Kameruns mit Fernerkundungs- und GIS-Techniken zu überwachen, an Bedeutung. Die Verfahren bieten eine Kosten-günstige Alternative, wenn viele Informationen gebraucht werden, die Mittel aber begrenzt sind. Dies ist meist der Fall bei kommunaler Waldbewirtschaftung. Mit allen angewendeten Verfahren konnten die meisten Waldflächenveränderungen lokalisiert werden. Jedes Verfahren hat seine Vorteile und offensichtlich gibt es kein optimales Verfahren um Änderungs-Detektion durchzuführen. Vielmehr hängt es von den jeweils verfolgten Untersuchungszielen (Lage, Typ, oder Natur der Veränderung) ab, welcher Verfahren geeignet ist. Die höchste Genauigkeit wurde mit der Band 5-Differenzierung und dem Vergleich nach Klassifikation- erzielt: jeweils 89,61 % and 89,12 %. Die NDVI-Differenzierung hatte eine Gesamt-Genauigkeit von 72,73 %; die Change Vector Analyse ergab 70,13 % während die Band 4-Differenzierung die niedrigste Genauigkeit von 61,04 % hatte. Die Univariate und NDVI-Differenzierungs- Techniken sind einfach und direkt einzusetzen. Sie identifizieren Veränderungen ohne zusätzliche Informationen über deren Typ und deren Natur. Die CVA und der Vergleich nach Klassifikation haben den Vorteil, qualitative Informationen über den Typ und die Natur der Veränderung abzuliefern. Der Vergleich nach Klassifikation ist die einzige Technik, die, Waldflächenveränderung mit höher Präzision identifiziert und abgrenzt, und gleichzeitig qualitative Informationen liefert. Die Genauigkeit kann durch das Hybrid Verfahren mit der Band 5-Differenzierung verbessert werden. Dieses kombinierte Verfahren bietet eine genaue Lokalisierung und zusätzliche qualitative Informationen. Die komplexe und dynamische Natur der Landschaft und die Wechselwirkungen zwischen Einflussfaktoren auf gleichen und verschiedenen Ebenen verlangt eine kontinuierliche Beobachtung mit Fernerkundungsanalysen und Feldforschungen. Waldflächenveränderungen in Kamerun werden von insgesamt drei Hauptfaktoren beeinflusst: dem Ausbau von Siedlungen, der Nutzung von Holz und der Verbreitung von Agrarflächen. Diese Faktoren treten in verschiedenen Formen auf und unterscheiden sich in den unterschiedlichen Regionen: Extraktion von Brennholz, kommerzielle Holzausbeutung, Einrichtung kleinräumiger Agrarfelder und Gründung von Agrarplantagen. Im Mount Kamerun Gebiet sind die Verbreitung von Agrarflächen für kommerzielle oder private Zwecke die Hauptursachen der Waldvernichtung. Während die kommerziellen Plantagen eine permanente Beeinträchtigung der Wälder zu Folge hat, hängt diese bei den kleinräumigen Agraraktivitäten von der Intensität, in der diese Aktivitäten durchgeführt werden, ab: je länger eine Flächebrach, desto wahrscheinlicher ist es, dass die Bodennutzung nachhaltig wird. Von den räumlichen Faktoren hat die Entfernung zu Strassen den größten Einfluss auf Waldflächenveränderung. Obwohl eine starke positive Korrelation zwischen Waldflächenveränderung und Entfernung zu Strassen, Entfernung zu Siedlungen sowie Hangneigung existiert, beeinflussen andere geophysische und sozioökonomische Faktoren die Waldvernichtung stärker als die räumlichen Faktoren, welche hier dargestellt sind. Andauernde Wolken sind weiterhin ein Hindernis für das optische Fernerkundungs-Monitorring der Vegetation in den Tropen. Diese Region ist dafür bekannt, dass sie mit optischen Fernerkundungsmethoden schwer zu überwachen ist, weil Wolken fast ganzjährig die Sicht versperren. Die Aufnahme wolkenfreien Bilder ist praktisch unmöglich. Die Region ist bekannt für die Schwierigkeit, sie mit optischen Fernerkundungsdaten zu überwachen. Es ist sinnvoll adäquate Möglichkeiten von aktiven Sensoren wie Radarsat, SAR, JERS in Zusammenhang mit passiven Sensoren zu erforschen, um die Wälder Mount Kamerun besser überwachen zu können.

The report consists of four chapters. Chapter 1 covers global policy development with an emphasis on climate change. It discusses the historical trend where CCUS first started as a measure to boost oil production in the time of an oil crisis and is now being increasingly promoted as a measure to tackle climate change issues. It also covers the trend in increasing investment by governments as CCUS is often promoted as an economic development vehicle. Chapter 2 discusses the technologies required for CCUS for each segment: the separation and capture of CO2, transport, utilisation, and storage. It introduces and explains the technical outline and discusses their application in ASEAN and the East Asia region. Chapter 2 reveals that most technologies involved in CCUS are proven and can be applied to ASEAN and East Asia even though consideration must be made to account for the long-time storage of CO2 if CCUS is implemented as part of a carbon credit scheme. It also covers new technologies that have attracted attention, such as direct air capture which removes CO2 from the atmosphere, leading to negative emissions. Chapter 3 describes business model case studies of some early-start projects with a focus on the hub and cluster model. It introduces the advantages of such a business model and some of the pre-existing conditions that have contributed to the early-start projects. It also discusses its development potential in ASEAN and East Asia. Chapter 4 explores the view towards creating a regional CCUS network in ASEAN and East Asia and its expected function for further promoting CCUS development in the region. It introduces discussions held at the CCUS panel session at the 3rd EAEF by key stakeholders comprising representatives from ASEAN governments, academia, multilateral development banks, the private sector, international organisations, and financial institutions, and the outputs referring to the need for a regional platform to further facilitate regional collaboration and capacity building to develop a workable CCUS business case in ASEAN.

Les travaux de recherche que j'ai menés depuis la soutenance de ma thèse en janvier 1996 représentent une tranche de vie ! Même si la plupart de ces années ont été passées au sein d'une même unité de recherche (Green) au CIRAD, j'ai vécu différentes périodes du fait des mouvements de mes collègues et de mes propres expatriations (en Thaïlande d'octobre 2005 à juillet 2009 et au Brésil depuis août 2015). Difficile dans ces conditions de trouver un fil conducteur. Je donne quelques éléments de contexte général sur la modélisation participative appliquée aux socio-écosystèmes dans le chapitre 2, en explicitant l'objectif spécifique de stimulation d'apprentissage social. Le chapitre 3 présente la première partie de mon parcours, jusqu'au début des années 2000 qui ont marqué l'émergence du collectif de chercheurs qui s'est constitué autour de la modélisation d'accompagnement. Au-delà de la présentation chronologique des éléments structurants de cette période, je discute d'un certain nombre de points de portée générale à la lumière de mon expérience et de mes lectures. Dans le chapitre 4, je donne un point de vue sur les modèles de simulation multi-agent appliqués à la gestion des ressources renouvelables et propose une classification des applications que j'ai développées avec la plateforme Cormas. Le chapitre 5tente de préciser les grandes lignes d'une approche de la modélisation d'accompagnement qui s'est construite au travers d'expériences de co-conception dirigée par la manipulation de modèles multi-agent de type "empirique stylisé" réalisées avec des acteurs locaux dans des contextes et des domaines d'application très variés (France, Bhoutan, Thaïlande, Cameroun, Zimbabwe). Je fais l'hypothèse que cette approche stimule l'apprentissage collectif, et en conséquence favorise l'émergence de formes d'interactions coopératives. Le chapitre 6, enfin, présente les trois directions de recherche vers lesquelles je m'oriente pour les prochaines années.

Dans les forêts sèches d'Afrique subsaharienne, les communautés rurales les plus exposées au risque d'insécurité alimentaire pendant les périodes de soudure alimentaire, utilisent les ressources forestières pour y faire face. Cependant dans la zone soudano-sahélienne d'Afrique de l'ouest, la savane est en train de régresser au profit des champs, où des arbres sont épargnés pour former des parcs arborés. Cette dynamique engendre un changement dans l'organisation du paysage à l'échelle du village et donc des services écosystémiques d'approvisionnement en produits forestiers disponibles. Elle rend nécessaire l'étude de l'impact de l'organisation du paysage sur la capacité des populations, notamment les plus vulnérables, à surmonter leurs difficultés alimentaires en période de soudure. Pour ce faire, deux territoires villageois très contrastés au point de vue du paysage mais comparables d'un point de vue agroclimatiques, car très proches l'un de l'autre ont été choisi afin d'étudier cette relation. La comparaison de ces deux villages nous a permis de démontrer que, quel que soit le type de paysage, les ménages les plus exposés aux risques alimentaires face à la variabilité climatique compensent les pertes de céréales alimentaires par des produits issus des arbres qui proviennent soit des formations naturelles (savanes, jachères), soit des parcs arborés, selon les types de paysages, et qui sont soit consommés, soit vendus pour acheter des céréales. Nous démontrons ainsi en région soudano-sahélienne la fonction de filet de sécurité alimentaire des arbres. Si les revenus issus des arbres ne parviennent pas à couvrir toutes les dépenses alimentaires des ménages les plus exposés au risque d'insécurité alimentaire, ils couvrent cependant les dépenses céréalières de ces ménages, ils sont la première source de revenus pour les ménages les plus vulnérables sur le plan alimentaire, très généralement détenus par les femmes, qui les utilisent pour acheter de la nourriture pendant une période de soudure alimentaire difficile. Outre le rôle de filet de sécurité alimentaire joué par les ressources forestières dans cette région, cette étude démontre également l'importance de l'organisation du paysage dans la mobilisation des produits forestiers pour surmonter la soudure alimentaire : bois et charbon là où la savane demeure encore la matrice du paysage ; noix de karité où ce sont les champs avec les parcs arborés qui en forment la matrice. Associés aux différents éléments de paysage, les droits d'accès et d'usage des ressources prennent dans cette perspective une importance toute particulière, notamment pour les ménages les plus vulnérables et pour les femmes en général. L'importance des ressources arborées et des droits d'accès des femmes à ces ressources pour surmonter les périodes de soudure alimentaire est ainsi démontrée pour la zone soudano-sahélienne du Burkina Faso. Ces résultats amènent à reconnaitre leur importance dans les politiques d'adaptation aux changements climatiques au niveau national, tout en garantissant une gestion durable de ces ressources.

Over the last fifteen years, Payments for Environmental Services (PES) schemes have become very popular environmental policy instruments, but the academic literature has begun to question their additionality. The literature attempts to estimate the causal effect of these programs by applying impact evaluation (IE) techniques. However, PES programs are complex instruments and IE methods cannot be directly applied without adjustments. Based on a systematic review of the literature, this article proposes a framework for the methodological process of designing an IE for PES schemes. It revises and discusses the methodological choices at each step of the process and proposes guidelines for practitioners.

Description du sujet. Les forêts du Bassin du Congo font partie des zones forestières les mieux préservées de la planète. Néanmoins, les facteurs qui entrainent la déforestation ailleurs dans le monde se manifestent également dans cette sous-région du globe. Cet article propose une revue de la littérature des causes directes et des facteurs sous-jacents de la destruction du couvert forestier des régions tropicales, afin de mettre en exergue les moteurs de la déforestation dans le bassin du Congo, et plus particulièrement au Cameroun et au Gabon. Littérature. Les causes directes de déforestation, définies comme ayant un lien cause-conséquence immédiat avec la destruction du couvert forestier, sont renforcées par des facteurs sous-jacents tels que les facteurs économiques, les avancées technologiques, les mesures politiques ainsi que les pressions démographiques. Toutes ces causes interagissent de façons distinctes dans les différentes régions tropicales de par le monde et expliquent les divergences et similitudes entre les dynamiques de déforestation régionales. En plus de l'expansion de l'infrastructure, du développement du secteur minier et de l'extraction du bois, l'agriculture représente la cause directe de déforestation la plus importante dans le bassin du Congo. Au Cameroun, la déforestation actuelle est principalement liée à l'agriculture. Le plan d'émergence de ce pays prévoit le développement des infrastructures, la modernisation de l'appareil de production national ainsi que l'exploitation minière. Au Gabon, le taux de déforestation plus faible s'explique par la dynamique agricole et l'ouverture des routes. Le plan d'émergence ambitieux y prévoit la modernisation de l'infrastructure ainsi que le développement de l'agriculture agro-industrielle. Conclusions. Une mutation des socio-écosystèmes liée à la déforestation est attendue en différents points du bassin du Congo. Les recherches futures devraient maintenant aborder la description de socio-écosystèmes types représentant les différents stades de la transition forestière ainsi que l'identification des facteurs du changement à différentes échelles.

Este estudio evaluó cuales factores han influido la adopción de prácticas de conservación y aumento de la Cobertura Arbórea en Fincas (CAF) en tres zonas rurales de Costa Rica. Se complementó información de censos poblacionales y datos geo-espaciales con resultados de entrevistas y talleres con 163 productores, aplicando un enfoque de indagación apreciativa y el marco de capitales de la comunidad. Los resultados confirman que también utilizando indicadores de desarrollo basado en estos enfoques y trabajando con CAF en paisajes agrícolas, es válida la teoría de la transición forestal (Mather 1992). Además se sugiere que si el proceso de desarrollo pone mayor énfasis en fortalecer el capital social (capacidad de organización, intercambio de información) y humano (salud, educación, asistencia técnica), existirá mayor probabilidad que el desarrollo irá acompañado por un proceso de recuperación de la CAF. La combinación de estos factores surtió un mayor efecto sobre la CAF que la Ley Forestal de 1996 y su programa de pago por servicios ambientales (PSA).

L'usage efficient de matières résiduaires devient essentiel lorsque les ressources se raréfient. Afin de répondre à cette problématique par une approche industrielle, des stratégies à adopter sont plus efficientes lorsqu'elles sont développées à des échelles systémiques, notamment par des symbioses industrielles territoriales (SIT), plutôt qu'à un niveau individuel ou isolé. Un projet de SIT invite ainsi différentes activités économiques présentes sur un territoire à s'engager de manière collective afin de modifier structurellement le métabolisme territorial. Ce type de projet peut être impulsé par des organisations ou individus légitimés par le réseau d'acteurs de la SIT en devenir. Une équipe facilitatrice peut initier la démarche en se basant sur la formulation d'une promesse plausible de bénéfices, progressivement adaptée avec la participation des acteurs qui concourent à la conception, puis l'implémentation des scénarios, dépendamment de leurs 'modèles de décision' , lesquels incluent entre autres des dimensions environnementales. Alors que l'évaluation environnementale de produits a fait l'objet d'intenses efforts de développements, la considération concrète de conséquences environnementales de projets de SIT reste très vaguement explorée et l'Analyse du cycle de vie (ACV) est présentée comme une méthode de choix pour l'évaluation environnementale de SIT. L'ACV n'intègre cependant ni le caractère subjectif de l'environnement pour appréhender le modèle de décision des acteurs, ni les changements structurels industriels pluriannuels induits par une SIT et leur effets sur l'environnement dans le temps. Partant de ces constats, et nous basant sur des recherches en sciences sociales, nous proposons une approche de conception anthropocentrée de l'environnement invitant à conceptualiser l'environnement comme un système de relations complexes sujet-objet, et pour lequel nous identifions des éléments clés de représentation de conséquences environnementales. L'identification de ces éléments clés nous a permis de constituer une base logique composée de trois environnements, permettant donc de couvrir la perception de --et donc de considérer conséquences sur-- l'environnement du point de vue des acteurs. Nous présentons une méthode participative qui intègre cette base logique et permet successivement 1) d'identifier les phénomènes environnementaux d'intérêt du projet de SIT, 2) de concevoir des indicateurs afférents au regard des connaissances relatives au territoire dans sa dimension biophysique et des mécanismes biophysiques mis en jeux, 3) d'estimer les conséquences environnementales du projet. Nous illustrons l'application de ces propositions méthodologiques pour un projet de gestion territorialisée de résidus organiques valorisés en agriculture à la Réunion.

Land use governance in the Brazilian Amazon has undergone significant changes in the last decade. At the national level, law enforcement capacity has increased and downstream industries linked to commodity chains responsible for deforestation have begun to monitor some of their suppliers' impacts on forests. At the municipal level, local actors have launched a Green Municipality initiative, aimed at eliminating deforestation and supporting green supply chains at the territorial level. In this paper, we analyze the land use transition since 2001 in Paragominas-the first Green Municipality-and discuss the limits of the governance arrangements underpinning these changes. Our work draws on a spatially explicit analysis of biophysical variables and qualitative information collected in interviews with key private and public stakeholders of the main commodity chains operating in the region. We argue that, up to now, the emerging multi-level scheme of land governance has not succeeded in promoting large-scale land use intensification, reforestation and rehabilitation of degraded lands. Moreover, private governance mechanisms based on improved product standards, fail to benefit from potential successful partnerships between the public and private sector at the territorial level. We propose a governance approach that adopts a broader territorial focus as a way forward.

L'objectif du projet de recherche RIME/PAMPA est de caractériser et d'évaluer les impacts ou effets des Systèmes de culture sous Couvert Végétal (SCV) dans les pays en développement. Cette évaluation s'est déroulée entre 2009 et 2012 dans diverses régions de 6 pays partenaires (Brésil, Cameroun, Laos, Madagascar, Tunisie, Vietnam). Elle a été réalisée aussi bien d'un point de vue agro-environnemental (outils de suivi et modélisation de la séquestration de carbone sous SCV, impacts écologiques), que socio-économique (situation de l'adoption des nouveaux systèmes de culture et dynamique d'innovation au sein des exploitations et des territoires). Arrivées en fin de projet, les équipes RIME/PAMPA ont organisé un atelier de capitalisation ouvert à la communauté scientifique et aux partenaires de développement. Les pays du Maghreb étaient représentés à cet atelier par l'Université de Tunis, l'Institut National Agronomique de Tunis et deux agriculteurs pratiquant ou expérimentant le semis direct au Maroc (Moyen Sébou) et en Tunisie (région de Mateur).

Le renforcement des préoccupations vis-à-vis des problématiques de développement, de bien-être des populations et de qualité des écosystèmes, génère de nouvelles pressions économiques (labels, cahiers des charges, etc.), normatives (règlements, fiscalité), et de la société civile (consom'action, boycott), et impose aux entreprises de prendre en compte ces problématiques, c'est-à-dire d'identifier, d'évaluer, et d'améliorer leurs impacts. De nombreux outils existent pour évaluer les impacts des chaînes de produits mais seules les méthodes d'Analyse de Cycle de Vie permettent d'avoir une évaluation multicritère et globale, et de rendre compte des transferts d'impacts d'une étape à l'autre du cycle de vie et d'un impact à l'autre. Le développement de l'ACV sociale est vivement souhaité et réclamé par les acteurs. La problématique de cette thèse a consisté à s'interroger sur les principes d'élaboration d'une telle méthode, son cadre conceptuel, théorique et méthodologique. Les besoins de recherche identifiés étant nombreux, les contributions spécifiques de cette thèse ont été triples : i) proposer un nouveau cadre théorique et conceptuel adressant les problématiques de bien-être et de développement, ii) élaborer une relation permettant d'évaluer les impacts de la création d'activité économique et de revenus sur la santé des populations, le " pathway Preston " iii) proposer un cadre méthodologique articulant le Modèle à Capitaux Multiples et le concept de capabilités. Les filières agroalimentaires et plus particulièrement les filières d'importation de fruits et légumes tropicaux, ont servi de cadre empirique à ce travail.

Regards sur la Terre décrypte la complexité des processus qui composent le développement durable et en révèle toute la richesse. La première partie dresse le bilan de l'année 2012 : retour sur les dates qui ont marqué l'avancée des connaissances et la construction de l'action dans les domaines du climat, de la biodiversité, des ressources naturelles, de la gouvernance, de l'énergie, de la santé ou du développement ; analyse des événements clés et des tendances émergentes, identification des acteurs majeurs, des enjeux et des perspectives. Le Dossier 2013 traite des relations entre l'accroissement des inégalités contemporaines et l'insoutenabilité de nos trajectoires de développement. Les inégalités sont-elles un obstacle au développement durable ? La réduction des inégalités est-elle un prérequis à un mode de développement plus soutenable ? Vingt ans après le Sommet de la Terre de Rio, les aspects sociaux du développement et de la croissance ont en effet pris une place prépondérante dans le débat public. La frontière historique entre les préoccupations présumées pour l'environnement des pays de l'OCDE, actuellement en crise, et le désir légitime de croissance des pays émergents en pleine expansion semble aujourd'hui s'être brouillée et les équilibres mondiaux profondément transformés. Sous l'effet de la crise économique, les écarts de revenus entre pays riches et pays en développement n'ont fait que diminuer, mais les inégalités au sein même des pays n'ont jamais été aussi fortes, avec des conséquences immédiates sur la santé, l'urbanisation, la biodiversité. Objet de préoccupation commune, nécessitant la mise en oeuvre de politiques novatrices à l'échelle internationale, la question de la réduction des inégalités est au coeur des objectifs d'un développement qui permette à chacun un niveau de vie convenable tout en préservant les besoins des générations futures. Fruit d'une coopération entre l'AFD (Agence française de développement), l'Iddri (Institut du développement durable et des relations internationales) et le TERI (The Energy and Resources Institute), Regards sur la Terre constitue un outil d'information et de compréhension indispensable.

POLITICS BY PROVINCE: Goal-oriented rational action or value-oriented rational action in closed debate on the Wadden region and public consultation on the ecological infrastructure General This thesis is a study of political conduct, and of provincial politics in particular. It is based on three research projects. The first two research projects are empirical studies that examine, respectively, the functioning of the discussion platform for government bodies relating to the Wadden Islands area and the relationship between the regional press and provincial political organs. Each of these two projects is based on a defined problem, a theoretical framework, methodology and conclusions. Although both case studies deal with provincial politics, they are completely separate from each other. The third case study is theoretical. It seeks to clarify the rationalization theories of Max Weber and Karl Mannheim, and place the concepts of goaloriented rational action and value-oriented rational action in their theoretical context. This theoretical chapter produces a number of research questions that can be used as a 'rationality grid' to be applied to the two empirical case studies in order to determine what form of action, goal-rational or value-rational, characterizes provincial politics. Chapter One describes the background to the studies and gives a short introduction to the research themes. This chapter also presents a view of contemporary provincial politics and discusses the scientific position from which this thesis has been written, emphasizing the unique role of the sociological vision. How does the government manage the Wadden Sea? The first section examines the way in which the government manages the Wadden Sea. The study is based on an evaluation study of the functioning of the Coördinatiecollege Waddengebied (CCW) in the period 1987 to 1994. The CCW (a platform for administrative consultation between the government, the Wadden provinces and the Wadden municipalities) was set up in 1980 for the purpose of "ensuring coherent administration and an coordinated policy by the government, provinces and municipalities with regard to the Wadden region." The study is based on a bottleneck analysis; in other words, by identifying problems, concrete solutions can be proposed. The evaluation study employed a combination of two popular lines of research in organizational sociology literature – the 'whole-system approach' and the 'parties approach'. In the whole-system approach, shared values or a feeling of solidarity are what unites the organization. In the parties approach, the organization is seen as a coalition of parties with different interests and aims. The parties work together for their own benefit, or because negative sanctions force them to do so. Both approaches are integrated in the 'parties-withina-system' perspective, which focuses on the relationships between the parties and the organization as a whole. This integral approach was used to evaluate the functioning of the CCW because the CCW places great emphasis on shared values and responsibilities, which are the core elements of the whole-system approach. At the same time, however, the CCW is composed of different parties which all have their own tasks, powers and interests – the core elements of the parties approach. This perspective has been tailored to the evaluation of the CCW using the following criteria: shared values, support base, differing interests, power structure, sense of purpose, and success/failure factors. The study is based on qualitative interviews with participants in the CCW platforms, telephone interviews with councillors and members of the States General, dossier analyses and reconstructions from minutes from the CCW consultations on the following cases: enlarging the scope of the Nature Conservation Act; delegation of powers with regard to inspection and control; co-ordination of international activities, problems relating to 'traditional brown shipping'; the review of the Waddenzee II Key Planning Decision, and gas extraction in the Wadden Sea. This treatment of the original research report emphasizes a systematic description of conduct within the context of the administrative co-ordination of the Wadden region, which is usually of a closed nature. The main problem areas are the following:  a lack of shared values due to the fact that the purpose of the Wadden consultation platform is given a different interpretation depending on the interests in question;  by way of preparation for the Wadden consultations, a process of harmonization takes place within the various authorities, thereby creating an administrative support base. However, this process of preliminary consultation and feedback reveals the other side of the bureaucratic coin – this circuit is, administratively and politically speaking, strongly inward-looking;  there are no substantial conflicts of interest between the layers of government. However, mutual suspicion exists with regard to the extent to which other parties are committed to the Wadden policy. Each party suspects that the other parties will ultimately allow economic interests to prevail;  with regard to the delegation of authority, the balance of power between the government and the provinces is seen as unacceptable. The continuous lack of consensus, whether manifest or otherwise, is a barrier to discussion on a equal footing;  there are various problems relating to the sense of purpose, including the role of the Chairman and the lack of a clear definition/delegation of tasks. This analysis shows that the problems are not related to the structure of the Wadden consultative platform but rather to its culture, and more specifically to the participants' perceptions of the role and responsibilities of the platform. In addition, there appears to be a distinct lack of leadership. The main conclusions are as follows:  harmonization within the various Wadden authorities (government, provinces and municipalities) hampers harmonization between the Wadden authorities;  the representatives from the three layers of government do not present the role and purpose of the consultative platform in a consistent and uniform way;  the CCW is hampered in its work by an ongoing debate about how powers are delegated between the layers of government. Because the analysis of success and failure factors revealed that clearly defined relationships between the government authorities are essential for successful consultation, possible solutions aim to create that clarity. Recommendations have been laid down, for example, relating to the role of the Chairman, drawing up the agenda, and clearly defining the tasks of the various bodies. Although, as far back as 1995, the CCW largely acknowledged the problem areas and supported the proposals for improvement, none of the recommendations will actually be implemented before 2001. Politics and the press on the ecological infrastructure in Friesland and Drenthe Section 2 describes a study of the relationship between the regional press and northern provincial politics. The basis for the study is the political decision-making regarding the establishment of the ecological infrastructure in the provinces of Friesland and Drenthe in the period 1989 to 1996. The conclusion of a survey of the relationship between the printed press and parliamentary democracy is that the main function of the press is to provide information, criticism and comment. The role of information-provider is examined on the basis of the following:  actual report of a meeting of the Provincial Councils;  a news report giving information about matters relating to the ecological infrastructure in both provinces;  a background article describing the context, history and/or different interpretations of matters relating to the ecological infrastructure. The role of critic is examined on the basis of the following:  editorial comment;  a column in which one of the editors gives his opinion under his own name;  opinions of third parties, in which a third party, who is not an editor, is given the opportunity to express an opinion. Using four recent examples, it is then argued that the central question relating to the relationship between politics and the press is one of management – who controls political communication or, put another way, is the relationship determined by 'party logic' or by 'media logic'? The study will compare decision-making on the ecological infrastructure (as this was perceived in decision-making meetings of the provincial councils) with reporting by the regional press in both provinces. The decision-making process of the provincial councils was reconstructed for this purpose. The result is not only an analytical reconstruction of the decision-making surrounding the ecological infrastructure in Friesland and Drenthe, but also a chronicle of provincial political customs and morals. A quantitative and qualitative analysis subsequently shows how the regional press fulfils its role as information provider and critic. The quantitative analysis addresses the question of how often the press fulfils its role as information provider and critic with regard to decision-making on the ecological infrastructure. The qualitative analysis addresses the question of how the press fulfils those roles. It is argued that the quality of the information provided is determined by the degree of objectivity, but that the best measure of quality is a clear standpoint. These conclusions were used to formulate an 'ideal' against which the quality of informative and critical articles can be measured. A factual report is as objective as possible when:  it deals not only with the decision itself, but also with the opinion-forming process;  it gives the opinion not only of the representatives of official bodies, but also of opponents or those outside such bodies;  the reporter does not give his own opinion. A news report or background article is as objective as possible when:  it presents more than one perspective and/or quotes more than one authority on the subject. An editorial or column makes a constructive critical contribution when:  the author adopts a clear standpoint;  the context (history, background or current event) of that standpoint is given;  the author describes how the standpoint was reached, and on which information or authorities it is based. Conclusions about the information function:  in almost half of the cases, the regional newspapers do not report on provincial council meetings relating to the ecological infrastructure. The people who live in the province, but fall outside a given environmental or agricultural target group, will not become informed about the ecological infrastructure by reading their local newspaper. Neither will they become informed about the role of the provincial government in this;  in the reports which do deal with meetings of the provincial councils, there is a lack of balance. Generally speaking, no effort is made in such reports to show the full palette of political colours represented in the provincial council;  there is only relatively wide newspaper coverage on occasions when political emotions are running high. Examples are: Friesland in 1993, when an agreement was reached with the agricultural sector, and Drenthe in 1993, when an amended programme of intent for the soil-protection areas was introduced (the agricultural lobby also played an important role in this). This attention from the press can be explained by incident politics. Political groups hold widely different opinions; they make no effort to hide their differences and journalists are keen to pick up on this. Another possible explanation is that, in these cases, ecological policy is heavily influenced by the farming lobby, which itself is strongly supported by influential political groups;  the news reports are usually brief and present an event from only one perspective, without a journalistic contribution from the author. This leads to the inevitable conclusion that press releases sent to the newspapers have been published without any further interpretation;  the most common simple perspective is that which opposes the ecological infrastructure;  there are very few background articles. Background articles that clarify the situation, and outline the problems confronting provincial politicians, are indispensable with regard to a far-reaching and complex plan such as the development of the ecological infrastructure of the two provinces;  it is notable that most of the background articles are only written from one perspective, with very little informative context. On the basis of these findings, it appears that the way in which the regional press fulfils its role as information provider leaves room for improvement. Scant attention is paid to council decision-making and the quality of reporting also leaves something to be desired. Little can be said about how the press fulfils the role as critic because so few articles appear in this context. The question Who controls political communication? cannot therefore be answered because the press pays too little attention to provincial politics. Goal-oriented or value-oriented rationality: which form of rationality determines political action? Section 3 examines which form of rationality (i.e. goal-oriented or value-oriented rationality) occurs most in the closed discussions between government bodies in the Wadden study, or in public discussions on the ecological infrastructure from the study of the relationship between politics and the press. For this purpose the rationalization theories from the work of Weber and Mannheim were used. Both Weber and Mannheim recognise increasing instrumental and formal rationality (Weber) and functional rationality (Mannheim) in all areas of life, and a decrease in material rationality (Weber) and substantial rationality (Mannheim). Weber and Mannheim identify the rise and influence of a specific form of instrumental rationality, particularly within economic, legal and bureaucratic institutions. Within such institutions, actions are characterized by goal-oriented rationality. This means that the prevalent institutional pattern of norms and values that more or less prescribes how people should act within the institutions (role-related behaviour) places great emphasis on goal-rational behaviour. In order to establish whether this also applies in provincial politics and administration, a study was made of the conception of rationality in the work of Weber and Mannheim. The question of whether goal-oriented or value-oriented rationality is dominant is addressed by a secondary analysis of the material. The secondary analysis takes the form of a 'rationality grid' that is applied to the material from the two empirical studies. The grid has a coarsely meshed structure that can separate out goal-oriented and value-oriented rationality. Following the study of Weber and Mannheim's concepts of rationality, goal-oriemted rational action is defined in this study as action that is geared towards finding the most appropriate means to achieve a goal that is considered as given. When action is successful in terms of the defined goal, we speak of goal-oriented rational action and formal rationality. Success or effectiveness is therefore the measure for goal-rational behaviour. The essence of this concept is expressed in the following questions:  is conduct geared towards resources and procedures within the given of administrative co-ordination or within the structured political (provincial) discussions?  are the goals open to discussion? If action is a logical extension of or derives from a higher value or ideal, we speak of 'valueoriented rational action' and 'material rationality'. The extent to which an action is valueoriented is therefore the measure for value-rationality. In this study, value-oriented rational action is defined as action that is based on the assessment of the desirability of a given goal by means of a party-political value system. The essence of the concept, as used in the present context, is expressed in the following question:  is the action geared towards assessing the desirability of a particular goal, based on a political value system? Conclusions: 1. With regard to discussion between government bodies on the subject of the Wadden region, the hypothesis was that, within the sphere of formalised and regulated administrative co-ordination in the Wadden region, actions are largely determined by goal-oriented rationality. The purpose of the discussion platform is, after all, to co-ordinate and realise goals defined elsewhere. The hypothesis is confirmed – the Wadden discussion platform is characterized by goal-oriented rational action. But this type of action is not related to the ultimate goal of the discussion platform but rather to another goal: the increasing of the influence and governance of the government layer in question. 2. With regard to the decision-making on the ecological infrastructure in Friesland and Drenthe, the hypothesis was that political decision-making debates are characterized by the discussion of values to be lived up to and aims to be realised. It is therefore to be expected that such debates are mainly characterized by value-oriented rationality. However, the findings do not confirm this hypothesis. The discussions of the provincial councils of Drenthe and Friesland are certainly not goal-rational in nature, yet neither can they be described as valuerational. Actions are indeed geared towards assessing the desirability of a particular goal, but that assessment is not based on a political value system. It is not party-political principles that determine political conduct; it would be more true to say that conduct is based on notions of consistency in terms of policy and support.

Tornare a interessarsi, ancora una volta, di morfologia dei tessuti urbani, di tipologie edilizie e di tecniche costruttive degli aggregati non è un atteggiamento un po' retrò, passatista di recidivi morfo-tipologi o di geografi urbani, bensì appare una necessità per chi cerca di definire criteri per una sostenibilità possibile e obiettivi effettivamente raggiungibili per l'edilizia diffusa delle città e in particolare di quelle mediterranee in tempi certi ancorché ardui da conseguire. L'evoluzione della città mediterranea è la dimostrazione, a ben vedere, di una forte resilienza che risiede nei caratteri della sua materialità e nella capacità che ha dimostrato di seguire la persistenza e la modificazione dei processi immateriali che la investono. Fine principale è pertanto quello di conseguire, o meglio ripristinare, una resilienza della struttura urbana compatta mediterranea (D'Amico e Currà 2014) e allo stesso tempo definire in termini realistici una sua possibile sostenibilità, consentendole di raggiungere, nel campo delle risorse, quegli obiettivi che la Comunità Europea ha posto, come una delle ragioni stesse della sua sopravvivenza: consapevoli tuttavia del fatto che gli obiettivi comunitari sono prevalentemente attagliati sul bene edilizio da costruire, sugli edifici a venire, e appaiono pertanto innovativamente raggiungibili solo in una fase espansiva dell'edilizia, che appare difficile da stabilizzare nell'attuale contesto economico e produttivo. La vecchia città europea è attualmente abbandonata nel territorio di un generico e quanto inefficace o dannoso retrofit, senza che ne venga analizzata in modo funzionale la fisicità della sua costituzione alla scala di tessuto edilizio e senza sapere quale sia l'entità del fenomeni fisici che la aggrediscono. Cosa fare dunque per impedire la sua violenta modificazione e la sua definitiva emarginazione nel mondo del reale piuttosto che in quello del virtuale, e in particolare della Città Compatta Mediterranea (CCM), unitamente ai caratteri locali che la determinano, travolta dalla vana rincorsa di obiettivi tecnologici irraggiungibili, ancorché vaghi, se non rivalutarla, considerarla per quei valori locali che la connotano e la identificano, senza sposare il riduttivo, debole approccio estetizzante alla sua mitica bellezza, oggi così di moda? Per ri_valutarla a partire dal suo campione, CCM appunto, è necessario determinare scientificamente il comportamento delle categorie che ne descrivono la forma e la struttura a livello di tessuto edilizio denso e compatto, mettendo a punto efficaci e affidabili strumenti di modellazione dinamica in grado di seguire studiosi e progettisti nel loro lavoro di analisi, di comprensione del fenomeno urbano ed edilizio e di adeguamento e prefigurazione del suo destino a venire; cercare, con quella pazienza, che secondo Le Corbusier contraddistingue sia la ricerca che la prefigurazione nella modernità scientifica, dapprima di verificare se esistano relazioni tra le varie categorie che la misurano e la caratterizzano (densità, morfologie, tipologie e tecniche costruttive) e i fenomeni fisici, micro_climatici che in CCM si verificano e che ne caratterizzano la prestazione meccanica d'insieme e l'urban phisics, il comportamento climatico appunto, piuttosto che esclusivamente energetico, e di misurarne valore e intensità. L'attenzione nei confronti di CCM e delle sue caratterizzazioni categoriali, in primo luogo morfo-tipologiche, a ha inizio, ancora una volta, nel territorio meccanico del suo comportamento in relazione agli eventi sismici che drammaticamente ne minano, sotto l'aspetto della sicurezza, la già compromessa agibilità. Per quanto attiene la sicurezza, la ricerca scientifica sul tessuto edilizio si concentra, quasi subito, sull'aggregato, definito, sulla scorta di diverse definizioni, come un sistema complesso, un insieme organico e strutturato di parti tra loro interagenti, il cui comportamento globale, di sistema appunto, non è immediatamente riconducibile a quello dei singoli elementi costituenti, dipendendo piuttosto dal modo in cui essi interagiscono. Ri_valutare un tessuto edilizio, un pezzo di città reale, richiede un approccio ambientale, alla resilienza, ben più complesso quindi di quello connesso alla sua sola agibilità e sicurezza, impone sotto i più diversi punti di vista prestazionali di guardare alla città, e in particolare a CCM, come a un insieme organico di aggregati, scegliendo la scala appropriata di rappresentazione e di dettaglio delle sue forme e di lettura delle varie criticità. Lo scopo ultimo di quest'approccio complesso alla ri_valutazione è quindi di ri_pensare disciplinarmente quegli strumenti che più efficacemente analizzano la building phisics, e quelli deputati alla valutazione di sicurezza urbana, mettendoli in relazione con la forma e la realtà costruttiva di ogni singolo edificio, rendendone possibile l'applicazione al tessuto urbano diffuso e la descrizione analitica dell'ambiente edilizio continuo e denso della città compatta. Vi è quindi un'importante necessità di ri_valutazione edilizia dell'aggregato che scientificamente permetta di legare i fenomeni costruttivi e tipologici al complesso delle prestazioni ambientalmente intese. A partire dall'organismo e giungendo quindi all'aggregato edilizio e al tessuto urbano è necessario che negli apparati di studio della costruzione anche storica si ponga maggior cura all'analisi delle modalità tradizionali, e non solo di resistenza al sisma (cui ci hanno richiamati maestri come Giuffrè e di Pasquale), ma anche è altrettanto significativo affrontare in maniera ambientalmente appropriata le problematiche di comfort e di gestione termo-igrometrica dei complessi manufatti edilizi. Le ri_leggendo nell'impostazione morfo-tipologica dell'organismo e dell'aggregato edilizio quelle soluzioni che, non connesse a specifiche tecnologie, sono meno ravvisabili. Gli ampi sottotetti, diversamente funzionalizzati, le diffuse incannucciate, le canne di ventilazioni, i vespai, i drenaggi attendono di essere ri_analizzati in ragione delle diverse condizioni climatiche del territorio che contribuiscono ad antropizzare. ; To once again turn our attention to the morphology of the urban fabric, of building typologies, and of the construction techniques of the whole, is not outdated behaviour favoured by morpho-typological recidivists or by urban geographers. Rather it is a necessity for the definition of the criteria for a plausible and objective sustainability for widespread building in the cities of the Mediterranean in a specific timeframe, even if these are difficult to obtain. The evolution of the Mediterranean city is proof of a resilience, which is rooted in its material characteristics, and in the ability to pursue the tenacity and the modification of its immaterial natures. The principal objective is to attain, or rather restore, a resilience of the compact urban Mediterranean structure (D'Amico and Currà 2014), and at the same time define a possible sustainability in realistic terms. This would allow the achievement of goals set by the European Union, for example regarding resources, as one of the very reasons for its survival, well aware that these EU objectives are primarily suited to construction projects yet to be carried out, on those buildings which will provide the memory of the future, and thus they appear both innovative and achievable, especially in a phase of production expansion which seems entirely outdated in the current economic context. The old European historical city is presently abandoned in realm of a generic and either ineffectual of damaging retrofit, without a functional analysis of its material makeup, and without knowing the nature of the physical phenomena attacking it. Therefore what is to be done to halt the violent modification and the definitive loss of this urban form? How is it to be salvaged from the fruitless pursuit of unreachable and vague technological goals, if not through re-evaluation? The city needs to be re-evaluated, to be considered for its own identifying and specific values, without taking the reductive, weak approach of simply lauding its celebrated beauty, so fashionable today. In order to avoid the unconditional and stagnant conservation of cities, the re-evaluation of historical buildings is crucial. For this reason, we should take into account the peculiar values that connote and determine themselves during the process of analysis. We should determine the different performances of a compact urban fabric in terms of built-form and urban structure. We need new dynamic energy evaluation methods and tools to estimate the relationship between the characteristics of the built environment (urban form, typology, construction technique, etc.) and the physical phenomena typical of the compact European city, making use of urban physics (urban climate and energy performances), and measuring their value and intensity.