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It is known that rocky macroalgae distribution depends on several abiotic factors, but little attention has been given to geomorphological influences. This paper analysed the relation between geomorphological variables (active processes, coastal morphology, coastal orientation and lithology) and rocky intertidal macroalgae species at a local scale. Thirteen sites were sampled along the coast of Cantabria (North Spain) in order to obtain covers of macroalgae species. Multivariate analysis and logistic regression were applied, predicting the probability occurrence of macroalgae species as a response to the predictor geomorphological variables. Our results showed that coastal morphology and coastal orientation were the principal geomorphological factors explaining the structure of macroalgae communities. The most significant differences in substrate preferences were found between Bifurcaria bifurcata, that appears in wave-cut platforms oriented towards the east, and Corallina officinalis/Ellisolandia elongata and Gelidium spinosum, which are found in cliffs oriented towards the north and west. Although these variables help to characterise species distribution, their predictive value is still limited, possibly due to other factors influencing macroalgae. Thus, some of the geomorphological variables studied here are among the environmental factors that determined the distribution of intertidal macroalgae communities at a local scale, even if not always in a direct way.
Data Types:
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Landslides are widespread phenomena that contribute to shape the landscape. Assessing the time sequence of landslide activity during the Holocene can help (i) better frame the present day landslide distribution in the wider context of climate change and (ii) better define landslide hazard to take adequate mitigation measures to preserve the elements at risk such as archaeological heritage and currently used structures and infrastructures. Rigorous image interpretation criteria applied to the interpretation of remote sensing images can be a valuable tool to derive information on landslide spatial and temporal distribution. However, it only allows to broadly estimate the relative age of landslides based on their morphologic signature. In this work, we investigate the topological relations between landslides and archaeological sites for nine selected settlements in the Moldavian Plateau, situated on ridges and hillslopes. Landslides and sites were mapped using high resolution LiDAR DEMs and extensive field validation activities. Landslides were classified as very old (relict), old, and recent, according to their morphologic appearance. We argue the possibility of (i) assigning a relative age to the three main classes of landslides as they appear on the present day topography, and (ii) assessing the landslide activity during the Holocene. Using this information, we set up a model of landslide evolution during the Holocene for the lowland of Eastern Carpathians. Based on collected data, we cannot exclude the Pleistocene age for some very old landslides, whereas the old and recent landslides appeared during the Holocene. We think this approach can be extended to other archaeological sites of the study area, and to other areas. Furthermore, similar studies can prove useful for landslide hazard analyses, helping to adopt adequate protection and mitigation measures, framed in a climate change scenario.
Data Types:
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The Tatra Mountains are the highest massif in the Carpathian mountain arc (2655 m) and represent a typical alpine landscape developed in the course of Pleistocene glaciations, but are not glacierized today. The glacial relief of the massif offers an abundance of topographic depressions (cirque overdeepenings, morainic closed depressions) where sedimentary sequences may potentially reveal paleoenvironmental changes that may have occurred since the glaciers' retreat from the Last Glacial Maximum position (∼26–18 ka). We present a review of Late Glacial and Holocene sedimentary archives from the Tatra Mountains collected in the Polish and non-Polish literature. The data sets (40 sites) included 21 lake, 13 peat bog, and 6 colluvial sediment sites. The entire listed sediment sequence features radiometric datings or at the very least a chronological framework is inferred from the biostratigraphy. The oldest sampled sedimentary sequences were dated back to the Oldest Dryas and were obtained from the deepest glacial lakes located in the subalpine zone (up to 1700 m). Shallow lakes (<10 m) and morainic closed depressions do not reveal sediments older than the Holocene. This can be linked with dry climate conditions and unfavorable hydrologic regimes during the Late Glacial when the studied depressions remained dry over the long term following deglaciation, irrespective of elevation and position in the glaciated valley system. For the Holocene, several millennial-scale phases of climate humidity and increased debris flow activity were identified. The intensification of debris flows is indicated at 9–7.5 ka and during the mid- to late Holocene (at ca. 6 ka, 3.5 ka, 2 ka, after 300 AD, 800–1000 AD, and LIA), separated by relatively stable climate conditions during the 'Holocene thermal optimum' (7.5–6 ka). The LIA in the Tatra Mountains was a relatively long (1220–1925 AD) and climatically unstable period, with a cold and dry first phase (1220–1540 AD), followed by a cold and humid phase (1540–1925 AD). During the modern warm period, renewed intensification of extreme slope processes has been recorded after 1970 AD.
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Although the climate development over the Holocene in the Northern Hemisphere is well known, palaeolimnological climate reconstructions reveal spatiotemporal variability in northern Eurasia. Here we present a multi-proxy study from north-eastern Siberia combining sediment geochemistry, and diatom and pollen data from lake-sediment cores covering the last 38,000 cal. years. Our results show major changes in pyrite content and fragilarioid diatom species distributions, indicating prolonged seasonal lake-ice cover between ∼13,500 and ∼8900 cal. years BP and possibly during the 8200 cal. years BP cold event. A pollen-based climate reconstruction generated a mean July temperature of 17.8 °C during the Holocene Thermal Maximum (HTM) between ∼8900 and ∼4500 cal. years BP. Naviculoid diatoms appear in the late Holocene indicating a shortening of the seasonal ice cover that continues today. Our results reveal a strong correlation between the applied terrestrial and aquatic indicators and natural seasonal climate dynamics in the Holocene. Planktonic diatoms show a strong response to changes in the lake ecosystem due to recent climate warming in the Anthropocene.
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Development of a clearer understanding of the causes and consequences of environmental change is an important issue globally. The consequent demand for objective, reliable and up-to-date environmental information has led to the establishment of long-term integrated environmental monitoring programmes, including the UK's Environmental Change Network (ECN). Databases form the core information resource for such programmes. The UK Environmental Change Network Data Centre manages data on behalf of ECN (as well as other related UK integrated environmental monitoring networks) and provides a robust and integrated system of information management. This paper describes how data are captured – through standardised protocols and data entry systems – as well more recent approaches such as wireless sensors. Data are managed centrally through a database and GIS. Quality control is built in at all levels of the system. Data are then made accessible through a variety of data access methods – through bespoke web interfaces, as well as third-party data portals. This paper describes the informatics approach of the ECN Data Centre which aims to develop a seamless system of data capture, management and data access interfaces to support research.
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This paper is a three-part assessment of the history of public housing in Richmond, Virginia and an account of current efforts to create a progressive model for public housing redevelopment in the city. Part One provides a short history of Richmond's creation of nearly exclusively African-American public housing in the East End of the city in the 1940s, 1950s, and 1960s, and describes a regional context in which virtually all public housing in the entire metropolitan area is located within a central city that is home to just one-sixth of the overall metro population. Part Two provides an account of the Blackwell public housing complex in Richmond under the Hope VI program, beginning in the late 1990s, and an account of the tenant activism that arose in response to the many problems and shortcomings with that project. That activism later resulted in the tenant-led coalition Residents of Public Housing in Richmond Against Mass Evictions (or RePHRAME). Together non-profit and tenant activists in RePHRAME have collaborated over the past several years to challenge redevelopment practices that threaten to diminish the number of public housing units in the city. Part Three is an in-progress report on an effort we are each personally involved in that includes participation by RePHRAME members as well as several community organizations and leaders that have been part of the RePHRAME coalition: to create a new resident-driven, progressive redevelopment process for the city. This process aims to build consensus among city policymakers and many tenants that redevelopment of the city's highly concentrated public housing units for the sake of improving opportunities and living conditions for residents is a moral imperative. Recognizing and articulating the history of segregation, mismanagement, and deep distrust between residents and public authorities, this process takes seriously the deep-seated and legitimate concerns of tenants with the aim of assuring much more positive outcomes in future redevelopment processes.
Data Types:
  • Geospatial Data
Translocality is a new phenomenon, recognized in reference to the migration of populations, city-planning and globalization. In our article, we attempt to introduce a new meaning of this term, referring it to the real estate market. Within the work, we research the phenomenon of real estate market subject translocality for all regions of Poland, design a coefficient for measuring translocality and, noting a similarity of the two phenomenon over time, indicate the practical significance of translocality in relation to the speculative price bubble.
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Legislation controlling vehicle emissions has been credited with a general downward trend in NOx (NO2+NO) concentrations in Europe since the 1990's. However, recent studies suggest that traffic (roadside) (TR) NO2 concentrations have not decreased as expected, and in some cases increased, most likely due to the use of oxidation catalysts and particle filters in diesel vehicles (EURO III, IV, V, VI). In this study we describe the time trends in NOx, NO2 and NO concentrations in 9 European cities comparing TR and urban background (UB) monitoring locations. In each city, we collected hourly city-specific NOx, NO, and NO2 data from one TR and one UB monitoring site for each year. We describe hourly, weekly, seasonal and inter-annual patterns for periods corresponding to the implementation dates of various EURO vehicle emission standards regulating NOx emissions. The diurnal patterns in all 9 cities strongly reflected morning and evening traffic. In addition, lower weekend concentrations were observed. The NOx concentrations from the TR sites remain unchanged in the majority of the cities over the study period. When stratified by 3 time periods according to the implementation of the EURO standards, an increasing NO2/NOx ratio in 7/9 cities with time was noted. However, over the same time period the NO/NO2 ratio decreased in 8/9 cities. A permanent inversion of the NO/NO2 ratio was observed to occur in 2003 in 5/9 cities. Our analyses of temporal and diurnal patterns of NOx in European cities show reductions in concentrations consistent with reductions in primary emissions likely arising from the implementation of successive EURO standards. The generally constant or increasing NO2 concentrations in the majority of the cities assessed over the study period underline the need of further regulative measures to meet the air quality standards and consequently to minimise adverse effects on human health. The ongoing collection and analysis of pollution concentrations across the EU is recommended to monitor trends in pollutants associated with adverse health effects.
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Ice-wedge polygon (IWP) peatlands in the Arctic and Subarctic are extremely vulnerable to climatic and environmental change. We present the results of a multidisciplinary paleoenvironmental study on IWPs in the northern Yukon, Canada. High-resolution laboratory analyses were carried out on a permafrost core and the overlying seasonally thawed (active) layer, from an IWP located in a drained lake basin on Herschel Island. In relation to 14 Accelerator Mass Spectrometry (AMS) radiocarbon dates spanning the last 5000 years, we report sedimentary data including grain size distribution and biogeochemical parameters (organic carbon, nitrogen, C/N ratio, δ13C), stable water isotopes (δ18O, δD), as well as fossil pollen, plant macrofossil and diatom assemblages. Three sediment units (SUs) correspond to the main stages of deposition (1) in a thermokarst lake (SU1: 4950 to 3950 cal yrs BP), (2) during transition from lacustrine to palustrine conditions after lake drainage (SU2: 3950 to 3120 cal yrs BP), and (3) in palustrine conditions of the IWP field that developed after drainage (SU3: 3120 cal yrs BP to 2012 CE). The lacustrine phase (pre 3950 cal yrs BP) is characterized by planktonic-benthic and pioneer diatom species indicating circumneutral waters, and very few plant macrofossils. The pollen record has captured a regional signal of relatively stable vegetation composition and climate for the lacustrine stage of the record until 3950 cal yrs BP. Palustrine conditions with benthic and acidophilic diatom species characterize the peaty shallow-water environments of the low-centered IWP. The transition from lacustrine to palustrine conditions was accompanied by acidification and rapid revegetation of the lake bottom within about 100 years. Since the palustrine phase we consider the pollen record as a local vegetation proxy dominated by the plant communities growing in the IWP. Ice-wedge cracking in water-saturated sediments started immediately after lake drainage at about 3950 cal yrs BP and led to the formation of an IWP mire. Permafrost aggradation through downward closed-system freezing of the lake talik is indicated by the stable water isotope record. The originally submerged IWP center underwent gradual drying during the past 2000 years. This study highlights the sensitivity of permafrost landscapes to climate and environmental change throughout the Holocene.
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Organic-rich black shale of the Upper Yangtze Basin from the Late Ordovician and Early Silurian is considered an excellent source rock in South China. The formation and preservation conditions of this resource are revealed by its geochemical characteristics in this study. Geochemical indices, including redox indices (V/(V + Ni), V/Cr, V/Sc, and Ni/Co) and primary productivity indices (P/Ti and Ba/Al), and paleoclimate, clastic flux and sedimentary rate analyses are presented to investigate the accumulation mechanism of organic matter. Redox indices suggest that a stagnant, anoxic environment predominated in the Upper Yangtze Basin during accumulation of Wufeng and Longmaxi formations. In contrast, ventilated and oxygenated marine conditions pervaded the Upper Yangtze Basin during deposition of Linxiang and Guanyinqiao formations. The concentrations of V and U demonstrate that accumulation of organic matter was mainly controlled by redox conditions. Besides, such factors as clastic fluxes, fresh water inflows or a mixed deposition with a rapid sedimentary rate cannot be ignored due to their influences on organic matter enrichment and preservation. However, weak co-variance relationship of TOC content and productivity proxies, including P/Ti and Ba/Al, demonstrates that the accumulation of organic matter was not controlled by primary productivity. Results of the present study suggest a depositional model that stresses the importance of tectonic movements and glacial events on the accumulation and preservation of organic matter. The model shows that the Upper Yangtze Basin was a semi-restricted basin system influenced by the isolation of Xuefeng, but also it implies that oxygen-depleted bottom water of the basin favored the accumulation and preservation of sedimentary organic matter, resulting in the formation of organic-rich black shale.
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