Heavy metal concentrations in surface sediments collected from 17 stations samples in Bizerte coastal line were determined in order to evaluate the contamination status in the region. Heavy metal ...concentrations (mg/kg) of Bizerte coast line followed the decreasing trend of Fe > Pb > Zn > Mn > Cu > Cr > Ni > Co > Cd. The pollution degree of the surface sediment collected from 17 samples station in Bizerte coast line by heavy metals was evaluated on the basis of pollution indices (EF, Igeo, CF, PLI and CD). Results of Igeo, EF, CF, PLI and DC demonstrated that pollution levels of Pb and Cd were moderate, which should require more attentiveness as main pollution factors. However, no pollution was found for Zn, Cu, Ni, Cr, Co and Mn. Hierarchical cluster analysis was used to identify the influence of anthropogenic activities on the surface sediment.
•Heavy metal (HM) concentrations in surface sediments collected from 17 stations samples in Bizerte coastal line.•HM was evaluated on the basis of, a EF, Igeo, CF, PLI and DC.•These results can be used as a useful tool for future monitoring of heavy metals pollutant.
Computerization has an essential role in the field of remote sensing. Various methods for automatic coastline analysis continue to develop. This study aims to determine the performance of three ...methods, namely Roberts' Filter, Segmentation, and Band Ratio on Landsat 8 imagery, in producing land edges that are directly adjacent to the sea area (coastline). This study shows that the non-fusion image, the resulting edge, is less sharp than the fused image in the Roberts' filter method. The use of a 2x2 matrix on the Roberts' filter, the range of values from 0.52 to 0.56 in the segmentation method, and the Green Band Ratio - Near-Infrared produce various accuracy. The best method is produced by Band Ratio, where the edge detection results are close to the image's actual conditions. Meanwhile, unsatisfactory results are produced by the segmentation method.
We are in a state of oceanic emergency. Climate change is battering the ocean with increasing heatwaves and acidification, and the loss of marine biodiversity is more evident than ever: more than 80% ...of marine biodiversity will be in danger by 2100 if we do not put an end to fossil fuels. However, the ocean remains the little cousin of climate summits and often also within the ecological struggle. One of the reasons that explains this phenomenon may be the minimal approach of citizens to the marine world, even in coastal cities and towns, as it is associated among other things with class privilege: sailing, diving or surfing are exclusive sports. In addition, the capitalist blindness that for years has turned dune cordons into beach bars and buildings and continues to use the coast as a tourist attraction or municipal dump have denigrated the seas that surround us literally and metaphorically.
The marine environment offers us the possibility of discovering wild and enigmatic species right here, without the need to make exotic trips or to enclose animals in aquariums. Perhaps on a beach much closer than you imagine live species of microalgae, marine plants, or fish as essential for life on the planet as forests or coral reefs are.
Estamos en estado de urgencia oceánica. El cambio climático azota al océano con olas de calor y acidificación crecientes, y la pérdida de biodiversidad marina es más evidente que nunca: más del 80 por ciento de la biodiversidad marina estaría en peligro en 2100 si no se pone fin a los combustibles fósiles. Sin embargo, el océano sigue siendo el primo pequeño de las cumbres climáticas y a menudo también lo es dentro de la lucha ecologista. Uno de los motivos que explican este fenómeno puede ser el ínfimo acercamiento de la ciudadanía al mundo marino, incluso en ciudades y pueblos costeros, ya que está asociado entre otras cosas al privilegio de clase: la navegación, el buceo o el surf son deportes exclusivos. Además, la ceguera capitalista que durante años ha convertido cordones dunares en chiringuitos y edificios y sigue utilizando el litoral como atracción turística o vertedero municipal han denostado los mares que nos rodean literal y metafóricamente.
El medio marino nos ofrece la posibilidad de descubrir especies salvajes y enigmáticas aquí al lado, sin necesidad de hacer viajes exóticos o de encerrar animales en acuarios. Quizás en una playa mucho más cercana de lo que imaginas habitan especies de microalgas, plantas marinas o peces tan esenciales para la vida en el planeta como los son los bosques o los arrecifes de coral.
Cilacap coast line is a part of southern coast of Java at Cilacap Regency, Central Java. Topographic and satellite image observation shown some ancient coast lines behind the modern coast lines. How ...many of the coast lines which have formed before the modern coast lines is the question to be answered. This research is the preliminary effort to determine the direction of coast line development and the amount of coast lines which have formed before the modern ones. This preliminary research of the ancient coast lines is done by two stages of work that are studio and field work. Studio work was done by observation and interpretation of topographic map, land use map, Google Earth image and SRTM image. At this stage of work was made an ancient coast lineaments map and geomorphic profiles of the research area. To the results of the interpretation which have been done then taken a field work verification by ground check. Interpretation to the coast lines of the research area has resulted 24 coast lines. Ancient coast lines lineament of the research area is in line with the modern ones which have east-west lineament and prograde from the north to southward.
La zona litoral rocosa esta entre los ambientes físicamente más extremos de la tierra. Los organismos que allí habitan son azotados alternadamente por factores físico-químicos y biológicos. Debido a ...la gran importan- cia ecológica que poseen estos ambientes, se estudió la diversidad, abundancia y distribución de la macrofauna bentónica del litoral rocoso, en la costa norte del estado Sucre, Venezuela. Se realizaron muestreos bimensuales, durante un año. La recolecta del material biológico se realizó de forma manual, dentro de una cuadrícula de 0.25m², en la zona litoral (supra, medio e infralitoral). Los organismos fueron preservados en formalina al 10% para su posterior identificación y análisis (parámetros ecológi- cos y prueba Kruskal-Wallis a la abundancia y diversidad). Se obtuvieron un total 19 020 organismos (86spp.), en 8 filos, 45 familias y 47 géneros. Los moluscos fueron los más abundantes y diversos (58 spp.), seguido de los artró- podos (12spp.), anélidos (7spp.), equinodermos (5spp.), y cnidarios, sipuncúlidos, nemertínidos y urocordados (1sp.). Los resultados encontrados, coincidieron con el esquema universal de zonación de Stephenson & Stephenson (1949). Las localidades de Río Caribe y Boca de Río presentaron los valores más altos de los parámetros ecológicos y Playa Grande los más bajos. Estadísticamente se observaron diferencias en la abundancia y diversidad de la macrofauna, entre las tres zonas. La poca información de la composición y distribución macrobentónica del litoral rocoso, impide una mejor comparación, no obstante los resultados contri- buyen al conocimiento de la biodiversidad marina en esta región venezolana.
The variability of storm surge poses a significant threat to coastal areas. A new metric named Accumulated Storm surge Potential Impact (ASPI) is proposed based on a new intensity parameter that ...removes other components from storm surge-induced water level rise. This new metric quantifies storm surge threat by combining frequency and intensity. The results show that storm surge threat has increased since the late 1990s due to greater general storm surges. The extreme storm surge threat did not follow the increasing trend until the mid-2000s. Different regional distribution patterns are found along this coast. The storm surge threat exhibited a -++ zonal tripole pattern, the negative phase was along the north coastline of Hangzhou Gulf and the positive phase was from the center to southern coast area of Zhejiang province and along the eastern coast area of Leizhou Peninsula. Long-term storm surge threats change spatial distribution pattern in three periods. More precarious threats from the center to southern coast areas of Zhejiang province illustrated a poleward shift of storm surge threats consistent with the trend of long-term tropical cyclone landfall. Meanwhile, the strong threat along the eastern coast line of Leizhou Peninsula was sustained from 1960 to 1995, then became weaker from 1996 to 2015. The evolution pattern of storm surge threat along the southeastern coastline of China could be applied for coastal adaptation research under climate change scenarios.
Fractals Schirmacher, Walter
Theory of Liquids and Other Disordered Media
Book Chapter
Recenzirano
The concept of self-similar geometric structures (fractals) with (generally) non-integer dimensionality is introduced. A prominent example is the percolation model, which exhibits a non-thermal phase ...transition. The percolation cluster at criticality is discussed in terms of scaling properties and critical exponents. It is shown that a random walk on a fractal leads to what is called anomalous diffusion.
The residency and small-scale movements of early juveniles (<175 mm fork length) of three sparid fish species were examined in the shallow subtidal zone along a 500 m stretch of rocky coastline near ...Schoenmakerskop (Eastern Cape Province, South Africa). A total of 12 blacktail (Diplodus capensis), 12 zebra (Diplodus hottentotus) and six white musselcracker (Sparodon durbanensis) were tagged using visible implant elastomer (VIE) tags. Underwater observations in four shallow rocky subtidal gullies and adjacent areas were made using snorkeling gear on a total of 37 days spanning 13 field trips over spring low tide periods between January and August 2006. The VIE tagging method was well suited to individually tag small juvenile fish with minimum disturbance. In general, the degree of residency of juveniles in the shallow rocky subtidal zone was species specific and dependent on the size of individuals. Juvenile zebra displayed the highest degree of residency followed by white musselcracker and blacktail, with re-sightings recorded on 53%, 40% and 10% of observation days, respectively. The high degree of residency by early juvenile sparids renders them vulnerable to localized coastal perturbations and climate change.
Las excavaciones desarrolladas por Manuel Sotomayor en 1972 en El Majuelo (Almuñécar, Granada) permitieron confirmar la existencia en el sector occidental de la ciudad de una amplia factoría de ...salazones de época romana. Sin embargo, a pesar de que las excavaciones en la factoría se sucedieron hasta mediados de la década de los ochenta del s. XX, los resultados de dicha campaña seguían aún inéditos. Presentamos aquí una revisión de los principales resultados obtenidos en los seis cortes realizados, centrándonos de forma particular en el hallazgo y documentación de la única evidencia segura de la existencia de algún tipo de estructura portuaria en el municipium Sexi Firmum Iulium. Se trata concretamente de un noray realizado en piedra, un elemento que consideramos que permite plantear la posibilidad de que el puerto romano de Almuñécar no funcionase simplemente como un fondeadero, tipología a la que podría responder en palabras de al-Himyari el puerto medieval, sino que en época romana contaría con cierto tipo de acondicionamientos destinados al amarre de las embarcaciones.
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