Spatio-temporal analysis of the coastline of faliro bay, attica, Greece

Coastal zone of Attica has been subject to constant changes generated by human interference during the last decades of the 20" century. Faliro Bay is located along the southwestern coast of Attica. Important changes are taking place in the area, due to human development that has irreversibly altered the physical features and has shaped the morphology of the bay. The aim of this paper is to record and monitor the coastline changes in Faliro Bay dunng a long-term penod. In order to detect the changes of the coastline, different methods, such as comparing topographical maps, aerial photographs and satellite imagery of different dates have been used.La zona costera de Attika ha sufrido cambios continuos en las últimas décadas del siglo 20 provocados por la intervención humana. La bahía de Faliro está localizada a lo largo de la costa sur-oeste de Attika. Significativas modificaciones han tenido lugar en la región, a causa del desarrollo humano que ha cambiado de forma irrevocable las características naturales y ha configurado la morfología de la bahía. El objeto de este trabajo es la presentación y el control de los cambios de la línea costera en la bahía de Faliro en un período de tiempo largo. Para el estudio de los cambios de la línea costera se ha utilizado la comparación de mapas topográficos, de fotografías aéreas y de imágenes de satélite

Geomorphological study of Kleinovitikos stream drainage network (Trikala prefecture - western Thessaly)

To Κλεινοβίτικο ρέμα είναι ένας από τους παραποτάμους του Πηνειού ποταμού στην Δυτική Θεσσαλία. Η Λεκάνη απορροής του αποστραγγίζει τμήματα των ορεινών όγκων του Κόζιακα και της οροσειράς της Νότιας Πίνδου. Στην παρούσα εργασία έγινε ποσοτική ανάλυση του υδρογραφικού δικτύου και διερευνήθηκε η σχέση της τεκτονικής με τις διευθύνσεις ανάπτυξης του υδροκρίτη και των κλάδων του υδρογραφικού δικτύου. Ο κύριος κλάδος του υδρογραφικού δικτύου είναι 6ης τάξης, ενώ η κυριαρχούσα μορφή του είναι η κλιμακωτή. Οι μορφολογικές κλίσεις των πρανών της λεκάνης παρουσιάζουν μεγάλες διακυμάνσεις με τις ομαλές και μέτριες τιμές μορφολογικών κλίσεων να αντιπροσωπεύουν περισσότερο μορφές διάβρωσης ενώ οι απότομες κλίσεις εκφράζουν γεωλογικές και τεκτονικές δομές. Κατά την ποσοτική ανάλυση του υδρογραφικού δικτύου διαπιστώθηκε ότι η γεωλογική και η τεκτονική δομή της περιοχής επιδρά άμεσα στην ανάπτυξη του. Επιπλέον, στις τιμές της υδρογραφικής πυκνότητας και συχνότητας επενεργεί η λιθολογική ανομοιογένεια των σχηματισμών της λεκάνης απορροής. Στην διεύθυνση του υδροκρίτη της λεκάνης απορροής επιδρά η λιθολογία και οι δευτερεύουσες διαρρήξεις. Οι κλάδοι 1ης έως και 3ης τάξης του υδρογραφικού δικτύου επηρεάζονται από νεοτεκτονικές διαρρήξεις, οι κλάδοι 4ης και 5ης τάξης επηρεάζονται από νεοτεκτονικές αλλά και παλαιότερες αλπικές διαρρήξεις ενώ ο κλάδος <?,ς τάξης επηρεάζεται από αλπικές διαρρήξειςThe Kleinovitikos stream is a tributary ofPineios River in the Western Thessaly. Its basin drainages parts of mountain range of Southern Pindos as well as the mountain of Koziaka. In this study a quantitative analysis of drainage network was accomplished and the relation of tectonics features with the watershed and the channels of drainage network were investigated. The main channel of the drainage network is of 6th order, while the dominated type of the network is the trellis drainage pattern. The morphological slopes of the basin show various fluctuations. The gentle slopes express erosional landforms while the steep ones represent geological and tectonic structures. It was noted by the quantitative analysis of the drainage network that the geological and tectonic structure of the area affects in its evolution. Moreover, the outcrop of heterogeneous lithological formations in the basin affects the values of drainage density and frequency. The lithology and the secondary cracks involve in the prevailing direction of the watershed. The streams of 1st -3r order are controlled by the younger cracks; the younger cracks as well as the older Alpine cracks have an influence on the streams of 4' and 5' order, and the Alpine tectonic activity affects the stream of 6' order

Assessment of rockfall hazard at Al-Noor Mountain, Makkah city (Saudi Arabia) using spatio-temporal remote sensing data and field investigation

Rockfall is one of the major concerns along different urban areas and highways all over the world. Al-Noor Mountain is one of the areas that threaten rockfalls to the Al-Noor escarpment track road and the surrounding urban areas. Thousands of visitors and tourisms use the escarpment track road to visit Hira cave which is located at the top of Al-Noor Mountain. In addition, the surrounding urban areas of Al-Noor Mountain are continuously spreading over the recent years. The escarpment track road and the surrounding urban areas are highly vulnerable and suffers from recurrent rockfall mostly in the rainy season. The steep and highly jointed slope along the different faces of the mountain makes these zones prone to failure due to different actions such as weathering, erosion and anthropogenic effect. Therefore, an attempt has been made in this study to determine the Al-Noor cliff stability, by identifying the unstable areas, and to apply the rockfall simulations. A combination of remote sensing, field study and 2D computer simulation rockfall program were performed to assess surface characteristics of the cliff faces. Bounce height, total and translational kinetic energy, translational velocity, and number of blocks have been estimated. Different unstable zones along the Al-Noor Mountain and escarpment track road were determined using filed investigation and remote sensing based image analysis. In addition the rockfall simulation analysis indicated that rockfall in zone 1 and zone 2 of the Al-Noor Mountain may reach the urban areas, whereas rockfall in zone 3 will not reach the urban areas, and rockfalls along the Al-Noor escarpment track road will have highly impact on the tourists. Proper preventive measures are also suggested to arrest the movement of falling rocks before reaching the urban areas and the Al-Noor escarpment track road. If proper care is taken, then further uncertain rockfall hazards can be prevented

Mapping of coastline changes in Athens Riviera over the past 76 year’s measurements

Mapping of coastline changes assists in coastal development and monitoring. Athens Riviera, located in the southwestern coastal zone in Attica in central Greece, has undergone major and radical changes generated by human interference during the last decades. The aim of this paper is to map record and measure the coastline changes in Athens Riviera over the past 76 years. Aerial photographs and satellite images from 1945 to 2021 as well as geographic information system (GIS) techniques were used to depict the spatial and temporal variations of the coastline. The results show that 60% of the total length of the coastline is artificial coast, while 29% is rocky coast and 12% beach. The study of seven subareas showed that human interventions caused significant coastline changes in Faliro Bay, Alimos and Glyfada. The adjacent coastal regions to Athens metropolitan area illustrate the highest modifications in the coastline. The main changes in the coastlines are recorded from 1960 to 1987, while the rate of changes in coastline slowed down from 1987 to 2021. The total changes in the coastline of Athens Riviera demonstrate that, during the past 76 years, the coastline was enhanced by 40% while land reclaimed to the sea area approaches 2.67 km2. The applied method is effective and rapid and may utilize in the coastal monitoring and management

Modelling urban growth evolution and land-use changes using GIS based cellular automata and SLEUTH models: the case of Sana'a metropolitan city, Yemen.

An effective and efficient planning of an urban growth and land use changes and its impact on the environment requires information about growth trends and patterns amongst other important information. Over the years, many urban growth models have been developed and used in the developed countries for forecasting growth patterns. In the developing countries however, there exist a very few studies showing the application of these models and their performances. In this study two models such as cellular automata (CA) and the SLEUTH models are applied in a geographical information system (GIS) to simulate and predict the urban growth and land use change for the City of Sana’a (Yemen) for the period 2004–2020. GIS based maps were generated for the urban growth pattern of the city which was further analyzed using geo-statistical techniques. During the models calibration process, a total of 35 years of time series dataset such as historical topographical maps, aerial photographs and satellite imageries was used to identify the parameters that influenced the urban growth. The validation result showed an overall accuracy of 99.6 %; with the producer’s accuracy of 83.3 % and the user’s accuracy 83.6 %. The SLEUTH model used the best fit growth rule parameters during the calibration to forecasting future urban growth pattern and generated various probability maps in which the individual grid cells are urbanized assuming unique “urban growth signatures”. The models generated future urban growth pattern and land use changes from the period 2004–2020. Both models proved effective in forecasting growth pattern that will be useful in planning and decision making. In comparison, the CA model growth pattern showed high density development, in which growth edges were filled and clusters were merged together to form a compact built-up area wherein less agricultural lands were included. On the contrary, the SLEUTH model growth pattern showed more urban sprawl and low-density development that included substantial areas of agricultural lands

Lanthanide-based time-resolved luminescence immunoassays

The sensitive and specific detection of analytes such as proteins in biological samples is critical for a variety of applications, for example disease diagnosis. In immunoassays a signal in response to the concentration of analyte present is generated by use of antibodies labeled with radioisotopes, luminophores, or enzymes. All immunoassays suffer to some extent from the problem of the background signal observed in the absence of analyte, which limits the sensitivity and dynamic range that can be achieved. This is especially the case for homogeneous immunoassays and surface measurements on tissue sections and membranes, which typically have a high background because of sample autofluorescence. One way of minimizing background in immunoassays involves the use of lanthanide chelate labels. Luminescent lanthanide complexes have exceedingly long-lived luminescence in comparison with conventional fluorophores, enabling the short-lived background interferences to be removed via time-gated acquisition and delivering greater assay sensitivity and a broader dynamic range. This review highlights the potential of using lanthanide luminescence to design sensitive and specific immunoassays. Techniques for labeling biomolecules with lanthanide chelate tags are discussed, with aspects of chelate design. Microtitre plate-based heterogeneous and homogeneous assays are reviewed and compared in terms of sensitivity, dynamic range, and convenience. The great potential of surface-based time-resolved imaging techniques for biomolecules on gels, membranes, and tissue sections using lanthanide tracers in proteomics applications is also emphasized