scholarly journals Παλαιοπεριβαλλοντική εξέλιξη της λιμνοθάλασσας του Κίτρους Πιερίας, ΒΔ Θερμαϊκός Κόλπος

2017 ◽  
Vol 44 ◽  
pp. 90
Author(s):  
Α.Σ. Δημητράκος ◽  
Κ. Βουβαλίδης ◽  
Γ. Συρίδης ◽  
Κ. Αλμπανάκης
Keyword(s):  
Sea Level Rise ◽  
Sea Level ◽  
The West ◽  
Rapid Phase ◽  
The Past ◽  
Initial Stage ◽  
Geomorphological Evolution ◽  
Low Rate

This paper deals with the palaeoenvironmental evolution of the Kitros Pierias Lagoon, located at the west coastline of the Thermaikos Gulf, during the upper Holocene. In addition, the palaeoenvi-ronmental units distinguished in the study area were correlated with the Holocene sea level rise in Thermaikos Gulf. The study is based on the sedimentological and stratigraphical analysis of a core 9.5 m long. Sedimentological and palaeontological analysis was carried out in all selected core sam-ples. The determination of the lithophases and biophases allowed the estimation of the stratigraphy-cal units, the interpretation of the geomorphological evolution and the characterization of the palaeo-environmental conditions. According to the results, we can conclude that the area under investigation was a transitional lagoonal environment, semi-enclosed at its initial stage progressively transformed to an isolated sallow basin. The formation of the semi-enclosed lagoon has been commenced after the conclusion of the rapid phase of sea level rise i.e. 6,000 BP years. Finally, the gradual isolation of the lagoon is attributed to low rate of the sea level rise e.g. over the past 4,000 years..

Salt marshes adjustment to anthropogenic pressures and sea-level rise

2021 ◽  
Author(s):  
A. Rita Carrasco ◽  
Katerina Kombiadou ◽  
Miguel Amado
Keyword(s):  
Sea Level Rise ◽  
Sea Level ◽  
Salt Marshes ◽  
Anthropogenic Pressures ◽  
The Past ◽  
Ria Formosa ◽  
Sediment Loads ◽  
Human Interventions ◽  
South Portugal ◽  
And Sea Level

<p>It is predictable that salt marshes in regions, where sediment loads are high, should be stable against a broader range of relative sea level scenarios than those in sediment-poor systems. Despite extensive theoretical and laboratory studies, additional syntheses of marsh ‘persistence’ indicators under human interventions and accelerated sea-level rise rates are still needed. This study investigates the recent lateral changes occurring in lagoon-type marshes of the Ria Formosa lagoon (south Portugal) in the presence of human interventions and sea-level rise, to identify the major drivers for past marsh evolution and to estimate potential future trends. The conducted analysis assessed the past geomorphological adjustment based on imagery analysis and assessed its potential future adjustment to sea-level rise (~100 years) based on modelled land cover changes (by employing the SLAMM model within two sea-level rise scenarios).</p><p>Salt marshes in the Ria Formosa showed slow lateral growth rates over the last 70 years (<1 mm∙yr<sup>-1</sup>), with localized erosion along the main navigable channels associated with dredging activities. Higher change rates were noted near the inlets, with stronger progradation near the natural inlets of the system, fed by sediment influx pulses. Any potential influence of sea-level increase to an intensification of marsh-edge erosion in the past, could not be distinguished from human-induced pressures in the area. No significant sediment was exchanged between the salt marshes and tidal flats, and no self-organization pattern between them was observed in past. The related analysis showed that landcover changes in the salt marsh areas are likely to be more prominent in the future. The obtained results showed evidence of non-linearity in marsh response to high sea-level rise rates, which could indicate to the presence of critical thresholds and potential negative feedbacks within the system, with significant implications to marsh resilience.</p>

scholarly journals Exceptional retreat of Novaya Zemlya's marine-terminating outlet glaciers between 2000 and 2013

2017 ◽  
Author(s):  
J. Rachel Carr ◽  
Heather Bell ◽  
Rebecca Killick ◽  
Tom Holt
Keyword(s):  
Sea Ice ◽  
Sea Level Rise ◽  
Sea Level ◽  
Remotely Sensed ◽  
Glacier Retreat ◽  
Remotely Sensed Data ◽  
Novaya Zemlya ◽  
The Past ◽  
Air Temperatures ◽  
The Impact

Abstract. Novaya Zemlya (NVZ) has experienced rapid ice loss and accelerated marine-terminating glacier retreat during the past two decades. However, it is unknown whether this retreat is exceptional longer-term and/or whether it has persisted since 2010. Investigating this is vital, as dynamic thinning may contribute substantially to ice loss from NVZ, but is not currently included in sea level rise predictions. Here, we use remotely sensed data to assess controls on NVZ glacier retreat between the 1973/6 and 2015. Glaciers that terminate into lakes or the ocean receded 3.5 times faster than those that terminate on land. Between 2000 and 2013, retreat rates were significantly higher on marine-terminating outlet glaciers than during the previous 27 years, and we observe widespread slow-down in retreat, and even advance, between 2013 and 2015. There were some common patterns in the timing of glacier retreat, but the magnitude varied between individual glaciers. Rapid retreat between 2000–2013 corresponds to a period of significantly warmer air temperatures and reduced sea ice concentrations, and to changes in the NAO and AMO. We need to assess the impact of this accelerated retreat on dynamic ice losses from NVZ, to accurately quantify its future sea level rise contribution.

scholarly journals CARACTERIZAÇÃO HIDRÁULICA DO MICROASPERSOR DAN SPRINKLERS GRUPO MODULAR

Irriga ◽  
2001 ◽  
Vol 6 (1) ◽  
pp. 13-18 ◽  
Author(s):  
Marcio Antonio Vilas Boas ◽  
Eurides Kuster Macedo Júnior ◽  
Silvio Cesar Sampaio ◽  
Melânia Inês Valiati
Keyword(s):  
Production Process ◽  
Power Function ◽  
Characteristic Equation ◽  
State University ◽  
The West ◽  
Potential Equation ◽  
Group 2 ◽  
The Relationship

CARACTERIZAÇÃO HIDRÁULICA DO MICROASPERSOR DAN SPRINKLERS GRUPO MODULAR                                     Márcio Antônio Vilas BoasEurides Kuster Macedo JuniorSilvio César SampaioMelânia Inês ValiatiUNIOESTE - Universidade Estadual do Oeste do ParanáCEP: 85814-110 - Cascavel – PR - Brasil - Cx. Postal   711Fone: (045) 225 -2100  (R-249) - Fax : (045) [email protected]  1 RESUMO  Este  trabalho  teve  como  objetivo  avaliar as características hidráulicas  do  microaspersor DAN SPRINKLERS do grupo modular de fabricação da DAN SPRINKLERS - ISRAEL, de uso recente no Oeste do Paraná. Os ensaios foram realizados no Laboratório de Hidráulica do Departamento de Engenharia da Universidade Estadual do Oeste do Paraná – UNIOESTE. Na  avaliação dos microaspersores  estudou-se, a variação decorrente do processo de fabricação e a determinação da equação característica da relação vazão–pressão. Os microaspersores do Grupo modular com diâmetros de bocais 0,94; 1,16;1,41;1,92 e 2,34 mm,  foram submetidos às pressões de 100, 150, 200, 250, 300 e 350 kPa. As equações características determinadas indicaram que o microaspersor testado não é auto-compensante , tolerante a sensibilidade de variações de pressões e que a equação potencial se ajusta bem aos dados. Os coeficientes de variação de fabricação obtidos foram menores que 5%, classificando-se, de acordo com a Norma ISO, como de categoria A. UNITERMOS: Microaspersão, coeficiente de variação, modelo potencial.  VILAS BÔAS, M. A., MACEDO JUNIOR, E. K. HYDRAULIC CHARACTERIZATION OF MICROSPRINKLER DAN SPRINKLER - MODULATE GROUP   2 ABSTRACT This work had as objective to evaluate the characteristics hydraulic of the microsprinklers of the group to modulate of production of DAN SPRINKLERS - ISRAEL, of recent use in the West of Paraná. The tests was accomplished in the Laboratory of Hydraulics of the Department of Engineering of the State University of the West of Paraná - UNIOESTE. In the evaluation of the microasprinklers it was studied such characteristics as, the variation due to the production process and the determination of the characteristic equation of the relationship vazão-pressure. The microsprinklers of the Group to modulate with diameters of nozzle 0,94; 1,16;1,41;1,92 and 2,34 mm, the pressures were submitted 100, 150, 200, 250, 300 and 350 kPa. The certain characteristic equations showed that the tested microsprinklers is not solemnity-compensante and that the potential equation was fit well to the data. The obtained coefficients of production variation were everybody below 5% being able to not this way to classify them in agreement with for ISO  category as A. KEYWORDS: Microsprinkler, coefficient variation, power function.

Geomophological and vulnerability analysis of a coastal delta under increased hydrological alteration over the past two centuries: Tana River delta, Kenya, East Africa.

2021 ◽  
Author(s):  
Peter Gitau ◽  
Stéphanie Duvail ◽  
Dirk Verschuren ◽  
Dominique Guillaud
Keyword(s):  
Sea Level Rise ◽  
East Africa ◽  
Sea Level ◽  
Coastal Dune ◽  
River Delta ◽  
River Channels ◽  
Dune System ◽  
The Past ◽  
Tana River ◽  
Coastal Dune System

<p>Coastal deltas worldwide are under risk of degradation due to the increasing impacts of sea-level rise, and continuous human alterations of river basin hydrology. This research highlights the geomorphological changes that have occurred within the Tana River delta in Kenya, an important deltaic ecosystem of high biodiversity value in East Africa.</p><p>The geomorphological features (river channels, floodplain, coastal dune system) and their evolution over the past two centuries were described. Aerial and satellite imagery was used to assess the magnitude and distribution of coastal changes from the 1960s to present.  Additionally, sediment cores recovered within the mangrove environment were analysed to establish the succession of sedimentation periods and patterns. Finally, we explored the response of the coastal processes of deposition and erosion under anthropogenic alterations of the hydrological system.</p><p>It was established that over the past two centuries Tana River has changed its main channel and outlet to the Indian Ocean on three occasions. A first river avulsion occurred in the 1860s, followed by a second avulsion in the late 1890s that was promoted by human interference through channel expansion and dyke construction. The third change in river course has occurred gradually over the past 20 years, amid human efforts to engineer the river channels.</p><p>From the sediment analysis and radiocarbon dating, it is ascertained that the lower deltaic region developed rapidly over the past ~180 years, facilitated by increased sedimentation from the main Tana River. On the other hand, analysis of the coastline changes indicate that there has been increased erosion of the coastal dune system and mangrove vegetation along the former river outlet, leading to rapid marine intrusion into local subsistence farming areas. By analysing the combined impacts of both natural river dynamics and human alteration we highlight how the integrity of the Tana River delta has increasingly become vulnerable under present sea level rise and continued upstream river alteration.</p>

Trends in Chesapeake Bay Sedimentation Rates during the Late Holocene

1990 ◽  
Vol 34 (1) ◽  
pp. 33-46 ◽  
Author(s):  
Joseph F. Donoghue
Keyword(s):  
Sea Level Rise ◽  
Chesapeake Bay ◽  
Sea Level ◽  
Late Holocene ◽  
Tide Gauge ◽  
Past Century ◽  
Sedimentation Rates ◽  
Relative Sea Level ◽  
The Past ◽  
Relative Sea Level Rise

AbstractTrends are discernible in the estimates of late Holocene rates of sedimentation and sea-level rise for the Chesapeake Bay. During most of the Holocene Epoch sedimentation rates and relative sea-level rise were equal, within the limits of measurement, at approximately 1 mm yr−1. Sedimentation rates measured over the past century, however, are nearly an order of magnitude higher, while the rate of relative sea-level rise for the Chesapeake Bay now averages 3.3 mm yr−1, as measured on long-term tide gauge records. When the acceleration in these rates occurred is uncertain, but it appears to have been confined to the past millennium, and probably to the past few centuries. The rapid sedimentation rates recorded during historic time may be a temporary disequilibrium that has resulted from a recent acceleration in the rate of relative sea-level rise.

scholarly journals Determination of the Criminal Offense Elements in the Safety Rules Violation during Mining Operations

2019 ◽  
Vol 105 ◽  
pp. 02012 ◽  
Author(s):  
Olga Safargalieva ◽  
Oleg Sergeev ◽  
Yuriy Volgin ◽  
Marina Agienko
Keyword(s):  
Systematic Approach ◽  
Basic Element ◽  
Mining Operations ◽  
Criminal Offense ◽  
Official Position ◽  
Initial Stage ◽  
The Subject ◽  
Safety Rules

In the article, from the standpoint of a systematic approach, the forensic characterization of safety rules criminal violations during mining operations is analyzed. That is the basic element which determines the content and algorithm of uncovering of crimes, the investigation and trial of a criminal case. The subject (the identity of offender) is its central, basic element. It is noted that the element of subject (the identity of offender) is the most informative when investigating criminal violations of safety rules during mining operations. It is based on his study in the unity and interrelation of the following aspects: official position, social and psychological properties and personality traits and victimization behavior of the criminal offence victims and third parties. The situation of a crime (the second element of forensic characterization) is structured according to the circumstances that characterize pre-, criminal, and post-criminal state of outward things; three interrelated and interdependent are pointed out. The complex combination of the levels and edges of each selected elements of a cognizable object, due to the specifics of the crime in question, also determines the peculiarities of investigative actions and search activities at the initial stage of the investigation of safety rules criminal violations during mining operations. The article proposes recommendations to overcome the objective difficulties encountered in the investigation of criminal violations of safety rules during mining operations.

TOWARDS THE IMPLEMENTATION OF CONTINUOUS COASTAL VULNERABILITY INDEX IN MALAYSIA: A REVIEW

2014 ◽  
Vol 71 (4) ◽  
Author(s):  
Gill J. Ainee ◽  
A.M. Anwar ◽  
S. Omar K
Keyword(s):  
Sea Level Rise ◽  
Sea Level ◽  
Vulnerability Index ◽  
Coastal Vulnerability ◽  
Pilot Projects ◽  
The West ◽  
Adaptation Measures ◽  
Coastal Vulnerability Index ◽  
Mitigation And Adaptation ◽  
Implementation Approach

Climate change has brought about many threats to the ecosystem by inducing natural hazards, particularly sea level rise. Coastal areas then are subjected to many adverse effects of sea level rise, hence posing a risk to the safety of the coastal population, resources and assets. As part of the mitigation and adaptation measures against these effects, the Coastal Vulnerability Index (CVI) was implemented by many coastal regions. The CVI is an index-based tool to map the risks related to coastal changes. In Malaysia, the practice of CVI is still in its initial stages. Whereby, the Department of Irrigation and Drainage (DID) Malaysia had earlier carried out two pilot projects on CVI. The first is located at Tanjung Piai and the second at the west coast of Pulau Langkawi. This paper reviews the definition and concept of CVI. An alternative implementation approach of CVI in Malaysia is also discussed.

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