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Urban green commons: Insights on urban common property systems 总被引：1，自引：0，他引：1
Johan Colding Stephan Barthel Pim Bendt Robbert Snep Wim van der Knaap Henrik Ernstson 《Global Environmental Change》2013,23(5):1039-1051
The aim of this paper is to shed new light on urban common property systems. We deal with urban commons in relation to urban green-space management, referring to them as urban green commons. Applying a property-rights analytic perspective, we synthesize information on urban green commons from three case-study regions in Sweden, Germany, and South Africa, and elaborate on their role for biodiversity conservation in urban settings, with a focus on business sites. Cases cover both formally established types of urban green commons and bottom-up emerged community-managed habitats. As our review demonstrates, the right to actively manage urban green space is a key characteristic of urban green commons whether ownership to land is in the private, public, the club realm domain, or constitutes a hybrid of these. We discuss the important linkages among urban common property systems, social–ecological learning, and management of ecosystem services and biodiversity. Several benefits can be associated with urban green commons, such as a reduction of costs for ecosystem management and as designs for reconnecting city-inhabitants to the biosphere. The emergence of urban green commons appears closely linked to dealing with societal crises and for reorganizing cities; hence, they play a key role in transforming cities toward more socially and ecologically benign environments. While a range of political questions circumscribe the feasibility of urban green commons, we discuss their usefulness in management of different types of urban habitats, their political justification and limitation, their potential for improved biodiversity conservation, and conditions for their emergence. We conclude by postulating some general policy advice. 相似文献
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Kord Ernstson Werner Mayer Andreas Neumair Dirk Sudhaus 《Central European Journal of Geosciences》2011,3(4):385-397
Sudden collapse of the Quaternary soil to form sinkholes on the order of meters and tens of meters has been a geologic phenomenon within living memory in a localized area north of Lake Chiemsee in Southeast Germany. Failing a satisfying explanation, a relation with an undefined glaciation process has always been proposed. Excavations and geophysical measurements at three newly affected sites show underground features such as prominent sandy-gravelly intrusions and extrusions typical of rock liquefaction processes well known to occur during strong earthquakes. Since strong earthquakes can reasonably be excluded to have affected the area under discussion, it has been suggested that the observed widespread liquefaction is related with the recently proposed Holocene Chiemgau meteorite impact event. Except for one earlier proposed but unassertive relation between impact and liquefaction, the obviously direct association of both processes in the Chiemgau area emphasizes that observed paleoliquefaction features need not necessarily have originated solely from paleoseismicity but can provide a recognizable regional impact signature. 相似文献
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Geochemical Atlas of Slovakia and examples of its applications to environmental problems 总被引：2，自引：0，他引：2
S. Rapant D. Bodiš K. Vrana V. Cvečková J. Kordík K. Krčmová I. Slaninka 《Environmental Geology》2009,57(1):99-110
Results of comprehensive geochemical mapping and thematic studies of the Slovak territory (rocks, soils, stream sediments,
groundwaters, biomass, and radioactivity) in the first half of the 1990s led to several new research programmes in Slovakia,
within the frame of which new methodologies for geochemical data evaluation and map visualization were elaborated. This study
describes the application and elaboration of data from the Geochemical Atlas of the Slovak Republic at national and regional
levels. Based on the index of environmental risk (IER = ΣPEC/PNEC), the level of contamination for the geological component of the environment in Slovakia was evaluated. Approximately
10.5% of Slovakia’s territory was characterized as being environmentally disturbed to highly disturbed. In the areas where
environmental loadings have accumulated, 14 regions where environmental risks existed due to high element concentrations were
defined. The model calculations of health risk estimates based on the databases of the Geochemical Atlas for groundwater and
soils indicate that the possible risk occurrence of carcinogenic diseases from groundwater arsenic contents is high in more
than 10% of Slovakia, whereas the chronic risk is negligible. To determinate the background and threshold levels a combined
statistical–geochemical approach was developed and applied as an example for groundwater at the national level as well as
for single groundwater bodies. The results of statistical method application for the whole groundwater body (GBW) were compared
with the background values for anthropogenically non-influenced areas in GBW. Final background value took into account time
variations and spatial distribution of the element in GBW. Furthermore, based on the database from the Geochemical Atlas for
groundwater, groundwater bodies potentially at qualitative risk were delineated for the whole of Slovakia. From a total of
101 groundwater bodies 17 were characterized as being at risk and 22 as being at possible risk. 相似文献
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Dr. Kord Ernstson 《International Journal of Earth Sciences》1984,73(2):483-498
The gravity survey of the Steinheim impact crater comprises about 500 gravity stations resulting in aBouguer anomaly map of the crater and its surroundings. From this map aBouguer residual anomaly of the impact structure was deduced which shows considerable character. A central negative anomaly with an amplitude of about -2 mgal and a halfwidth of 3 km is surrounded by ring-like relative positive and negative anomalies which extend to a radial distance of about 5–6 km. The interpretation is based on nine radial profiles with close station spacing. Model calculations were performed suggesting the Steinheim crater to be much larger and of different formation than has been assumed. Based on the gravity interpretation, on a morphological analysis, and on additional geological and geophysical observations a model of the Steinheim crater and its development is proposed. The main characteristics are a 500–600 m deep primary excavation and a final, apparent, diameter of roughly 7 km, contrasting to an up to now favoured shallow excavation and a 3.5–4 km final diameter. The model considerations include mass and energy calculations and references to the Ries impact crater.
Zusammenfassung Im Gebiet der Impakt-Struktur Steinheimer Becken wurden in Ergänzung zu früheren Untersuchungen neue Schweremessungen durchgeführt. Mit den nunmehr etwa 500 vorliegenden, nachBouguer reduzierten Schwerewerten wurde eine Karte derBouguer-Anomalien konstruiert, aus der nach Abzug eines Regionalfeldes eine Restfeld-Anomalie für den Impakt-Krater gewonnen wurde. Sie ist grob rotationssymmetrisch und zeigt außerhalb eines zentralen Schwereminimums von –2 mgal ringförmig angeordnete, relative positive und negative Schwereanomalien. Die Interpretation stützt sich auf neun radiale Profile erhöhter Stationsdichte, von denen vier für Modellrechnungen ausgewählt wurden. Auf Grund der berechneten Dichtemodelle, einer ergänzenden morphologischen Analyse der Kraterstruktur sowie zusätzlicher geologischer und geophysikalischer Befunde wird ein Modell für den Aufbau und die Entstehung des Steinheimer Beckens vorgeschlagen. Danach ist das heutige Becken mit einem Durchmesser von rund 3,5 km der Ausdruck einer primären Kraterstruktur, die in einer Exkavationsphase entstand und eine Tiefe von 500–600 m besaß. Ausgleichsbewegungen führten zu einer Massenkonvergenz und Anhebung in der Kratermitte und einer Absenkung außerhalb des primären Kraters, die die endgültige Struktur auf grob 7 km Durchmesser vergrößerte. Die Modell-Betrachtungen schließen Massen- und Energieabschätzungen sowie Vergleiche zum Ries-Krater ein.
Résumé La recherche gravimétrique dans le cratère d'impact de Steinheim et ses environs (Allemagne du Sud) comprend environ 500 stations de mesure qui ont été utilisées pour construire une carte des anomalies deBouguer. Un champ régional a été tracé pour obtenir l'anomalie résiduelle du cratère. On observe une anomalie négative (–2 mgal) au centre de la structure cernée d'anomalies positives et négatives relatives de faible amplitude, jusqu'à une distance radiale de 5–6 km. Pour l'interprétation neuf profils radiaux, où les stations sont à faible distance, ont été utilisés. Les modèles calculés pour quatre profils radiaux suggèrent que la structure de Steinheim est plus grande qu'on ne l'a supposé jusqu'à présent. En partant de l'interprétation des mesures gravimétriques, d'une analyse topographique du cratère et d'observations géologiques et géophysiques complémentaires un modèle de la structure Steinheim et de son développement est proposé. On en conclut que le bassin actuel avec un diamètre de 3,5 km est l'expression d'une structureprimaire du cratère qui s'est formée au cours d'une phase d'excavation et possédait une profondeur de 500–600 mètres. Des mouvements d'égalisation conduisirent à une convergence de masses avec soulèvement dans le centre du cratère et un affaissement à l'extérieur du cratère primaire, lequel s'accrut jusqu'à la structure finale de quelque 7 km. Le modèle inclut le calcul des masses déplacées et des énergies d'impact ainsi qu'une comparaison avec le cratère d'impact du Ries.
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An environmental risk assessment map of the Slovak Republic: application of data from geochemical atlases 总被引：6，自引：0，他引：6
A water budget analysis for the Cedar River watershed in northeastern Iowa was conducted to determine the water balance during the summer months of 2000. The watershed has eight major tributaries that comprise a drainage area of 20,242 km2, of which 81% is agricultural land. Water budgets are essential when examining the movement of agricultural chemicals as well as nutrients within the system. The water budget was determined using the hydrologic mass-balance equation, which states that [inflow = outflow - storage]. The inflow components were measured individually and included precipitation, tributary and Cedar River baseflow. The outflow components included evaporation, transpiration, tributary and Cedar River discharge. The results of this study indicate a slightly larger volume of water leaving the watershed (6.24᎒9 m3) than entering (6.21᎒9 m3). The surplus of the outgoing water (0.5%) is most likely due to an overestimation of transpiration, or the contribution of water from the intermittent streams not measured during the study. Calculations of nutrient flux showed that approximately 2.99᎒6 kg of nitrogen and 2.39᎒5 kg of phosphorus were lost from the watershed during the study. 相似文献
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Priv.-Doz. Dr. Kord Ernstson Dr. Johannes Fiebag 《International Journal of Earth Sciences》1992,81(2):403-427
A progress report on geophysical and geological investigations in the 35–40 km diameter Azuara probable impact structure (northeast Spain) is given. The target is a 10 km thick sequence of Palaeozoic, Mesozoic, and Cenozoic sediments. Gravity measurements establish a negative residual anomaly of about 100m/s2 and a mass deficiency of 1.24×1014 kg. They suggest the existence of a buried inner ring with half the size of the outer ring. The result of preliminary model calculations is compatible with the assumption of a flat structure only a few kilometers deep. Measurements of the total intensity of the Earth's magnetic field do not indicate causative bodies related to the structure. Geological mapping reveals a tectonic style which is characterized by folds and faults with radial and tangential elements and a strong horizontal component. Ejecta, abundant monomict and polymict breccias, dislocated megablocks, inverted stratigraphy, and a megabreccia up to 80 m thick in the outer ring are evidence for intense and violent deformation. Networks of typical breccia dikes well-known from many impact structure cut through nearly all stratigraphical units. Various types and generations of breccia dikes occur. In addition to previously described shock deformation in quartz and mica, we present further evidence of high-pressure and high-temperature signatures in rocks. The age of the impact is estimated to be Upper Eocene or Oligocene. We conclude that the formation of the Azuara structure is difficult to explain by mechanisms other than impact, and we discuss our observations within the scope of the contact/compression, excavation, and modification stages of impact cratering with special attention directed to the peculiarities of the Azuara sedimentary target.
Zusammenfassung Es wird über geophysikalische und geologische Untersuchungen in der Struktur von Azuara berichtet. Sie liegt in Nordost-Spanien, ist nach der gängigen Klassifikation eine wahrscheinliche komplexe Impakt-Struktur, hat einen Durchmesser von 35–40 km und ist in etwa 10 km mächtigen Sedimenten angelegt. Schweremessungen erbringen eine Restfeld-Anomalie von etwa –100m/s2 (–10 mgal) und ein Massendefizit von 1,24×1014 kg. Kleinräumige Anomalien können als Ausdruck eines inneren Ringes gedeutet werden; sein Durchmesser wäre grob halb so groß wie der des morphologischen Ringes. Einfache Modellrechnungen sind mit der Annahme einer sehr flachen Struktur anomaler Dichte verträglich. Messungen der Totalintensität des Erdmagnetfeldes geben keine Hinweise auf Störkörper, die mit der Entstehung der Struktur in Verbindung gebracht werden könnten. Nach Kartierungen und strukturgeologischen Untersuchungen ist ein tektonischer Stil gegeben, der radiale und tangentiale Elemente mit ausgeprägter horizontaler Komponente aufweist. Auswurfmassen, viele und verschiedenartige monomikte und polymikte Brekzien, dislozierte Schollen, inverse Stratigraphie und eine bis zu 80 m mächtige Megabrekzie im Bereich des morphologischen Ringes belegen ungewöhnliche und energiereiche Deformationen. Charakteristische Brekziengänge, die von vielen Impakt-Strukturen bekannt sind, durchschlagen nahezu alle stratigraphischen Einheiten. Verschiedenartige Typen und Mehrfach-Generationen von Brekziengängen treten auf. Früheren Beobachtungen von Schockeffekten in Mineralen werden neue Befunde zu Hochdruck- und Hochtemperatur-Einwirkungen hinzugefügt. Beim gegenwärtigen Stand der Kenntnisse ist es schwer, endogene Prozesse zur Entstehung der Azuara-Struktur heranzuziehen; die Annahme eines Impakts, der in das obere Eozän oder ins Oligozän datiert wird, ist zwingend. Die wesentlichen Phasen der Kraterbildung, soweit sie Lehrbuchwissen geworden sind, werden für die Azuara-Struktur erörtert.
Resumen Se presenta un informe detallado sobre las investigaciones geofísicas y geológicas realizadas en la probable estructura de impacto (compleja) de Azuara, con un diåmetro de 35–40 Km. Las medidas gravimétricas establecen una anomalia residual de alrededor de –100 m/s2 (–10 mgal) y una deficiencia de masa de 1.24×1014 Kg. Estas medidas sugieren la existencia de un anillo interno soterrado con un diámetro cuyo valor es la mitad del anillo externo. El resultado de los cálculos en un modelo preliminar es compatible con la admisión de una estructura plana de únicamente pocos kilómetros de profundidad. Las medidas de intensidad total de campo magnético terrestre descartan la presencia en profundidad de un cuerpo causante de la estructura. El mapa geológico revela un estilo tectónico caracterizado por pliegues y fallas con elementos radiales y tangenciales, y un fuerte componente horizontal. Ejecta, abundantes brechas monomícticas y polimícticas, megabloques dislocados, estratigrafia invertida, y una megabrecha de más de 80 m. de espesor loealizada en el anillo externo, constituyen evidencias de una deformación intensa y violenta. Redes de típicos diques de brecha, bien conocidos en otras estructuras de impacto, cortan casi todas las unidades estratigråficas. Pueden observarse varios tipos y generaciones de diques de brecha. Además de la previamente descrita deformación por efecto de choque en granos de cuarzo y mica, nosotros presentamos evidencias adicionales de efectos en las rocas generados a altas presiones y temperaturas. La edad de la estructura puede ser o Eoceno superior o Oligoceno. Concluimos que la formación de la estructura de Azuara es difícil de explicar por cualquier otro mecanismo que no sea un impacto, y discutimos nuestras observaciones dentro del ámbito de los estadios de contacto/compresión, excavación, y modificatión (presentes en la craterización por impacto), haciendo hincapié en las peculiaridades del objetivo sedimentario de Azuara.
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B. Kord Ph.D. A. Mataji Ph.D. S. Babaie Ph.D. 《International Journal of Environmental Science and Technology》2010,7(1):79-84
In this study, the pine tree (Pinus Eldarica Medw.) needles were evaluated as the biomonitors of heavy metal contamination in Tehran, Iran. The pine needle samples supplied from the old trees according to the main wind direction (highest wind speed) were obtained from each parts of tree and then were homogeneously mixed. The samples were taken from different locations with different degrees of metal pollution (urban, industrial, highway and control sites). Then, the concentrations of lead, zinc, copper, nickel and chromium were measured using a flame atomic absorption spectrophotometer. The result of this study showed that the highest and the lowest metal concentrations were found in the heavy traffic sites and the control site, respectively. However, samples taken from highway sites contained the high concentrations of nickel, copper and lead. Moreover, industrial areas were found to have high contents of zinc and chromium. The variation in heavy metal concentrations between the studied locations is due to changes in traffic density and anthropogenic activities. This research proved significant correlations between the heavy metal concentrations in pine needle samples. Finally, it is concluded that Pinus Eldarica Medw. needles can be applied to monitor polluted sites. 相似文献