scholarly journals The survival and behavioural responses of a near-shore chironomid and oligochaete to declining water levels and sandy substratum drying

Hydrobiologia ◽  
2016 ◽  
Vol 788 (1) ◽  
pp. 231-244 ◽  
Author(s):  
Małgorzata Poznańska ◽  
Dominika Werner ◽  
Izabela Jabłońska-Barna ◽  
Tomasz Kakareko ◽  
Klaudia Ung Duong ◽  
...  
Keyword(s):  
Water Levels ◽  
Behavioural Responses ◽  
Near Shore ◽  
Sandy Substratum

Extreme waves and surges interaction with tides during storms in winter 2013/2014.

2021 ◽  
Author(s):  
Julia Rulent
Keyword(s):  
Tidal Cycle ◽  
Grid Point ◽  
High Tide ◽  
Water Levels ◽  
Extreme Waves ◽  
Near Shore ◽  
The Uk ◽  
The Waves ◽  
Tidal Stage

<p>The interaction between waves, surges and tides is one of the main drivers of coastal total water levels (TWL).  Understanding this interaction is crucial for studying high TWL formation near shore, and to do this it is important to not only evaluate how high the TWL is but also when and where it occurs.</p><p>In this study we use a high resolution (1.5 km) three-way coupled (waves-atmosphere-ocean) numerical model developed by the MetOffice (UKC4) to study coastal conditions at the UK coast during the extreme events of winter 2013, which was chosen as case study because of the amount of flooding that occurred in relation to storms and surges during this period.</p><p>For each coastal grid point the ten strongest storms of that winter, ranked by the significant wave height (Hs) magnitude, were selected. During these storm periods, the number of hours in which Hs and surges exceeded the 90<sup>th</sup> percentile of winter 2013 were evaluated considering what tidal stage they occurred on. The same was done for instances where high Hs and surges occurred simultaneously. The aim is to understand if specific areas were predominantly affected by one of the TWL components and how Hs and surges interacted with the tide. What was the spatial distribution of the waves, surges, and tides during winter 2013? Did extreme Hs and Surges occur more often over specific stages of the tidal cycle? Did they occur simultaneously? </p><p>In this study we show that during the winter 2013, Hs and surges above the 90<sup>th</sup> percentile value did occur simultaneously at all stages of the tidal cycle. They more often occurred together over the rising tide with in average 8.7% and 8.6% of instances found two and three hours before high tide. In 7.7% of cases high wave and surges also concurred at high tide.</p>

scholarly journals Forecasting Storm Surge and Inundation: Model Validation

2017 ◽  
Vol 32 (6) ◽  
pp. 2045-2063 ◽  
Author(s):  
Jayaram Veeramony ◽  
Andrew Condon ◽  
Maarten van Ormondt
Keyword(s):  
Storm Surge ◽  
Stress Gradient ◽  
Forecast Model ◽  
High Water ◽  
Water Levels ◽  
Ocean Dynamics ◽  
Radiation Stress ◽  
Near Shore ◽  
The Impact ◽  
Inundation Model

Abstract Coastal regions are increasingly vulnerable to damage from storm surge and inundation. Delft3D is used by the Naval Oceanographic Office to model the ocean dynamics in the near shore. In this study, the performance of Delft3D in predicting the surge and inundation during Hurricane Ike, which impacted the northern Gulf of Mexico in September 2008, is examined. Wave height, water level, and high-water mark comparisons with a number of observations confirm that the model does well in predicting the surge and inundation during extreme events. The impact of using forecast winds based on the best-track data as opposed to hindcast winds is also investigated, and it is found that the extent of inundation is represented reasonably well with the forecast winds. In Delft3D, waves can be coupled to the hydrodynamic component using the radiation stress gradient method or the dissipation method. Comparing the results of using the two shows that for low-resolution grids such as that needed for a forecast model the dissipation method works better at reproducing the water levels and inundation.

scholarly journals DUNE EROSION PHYSICAL, ANALYTICAL AND NUMERICAL MODELLING

2012 ◽  
Vol 1 (33) ◽  
pp. 32 ◽  
Author(s):  
Felice D'Alessandro ◽  
Giuseppe Roberto Tomasicchio ◽  
Fausta Musci ◽  
Andrea Ricca
Keyword(s):  
Large Scale ◽  
Laboratory Data ◽  
Water Levels ◽  
Data Sets ◽  
Dune System ◽  
Dune Erosion ◽  
Storm Waves ◽  
Near Shore ◽  
Recession Rates ◽  
Model C

The present paper provides an overview of the large-scale physical model experiments performed at the Canal d’Investigaciò i Esperimentaciò Marìtima (CIEM), Laboratori d’Enginyeria Marìtima (LIM), Universitat Politècnica de Catalunya (UPC), Barcelona, within the EU-Hydralab III Integrated Infrastructure Initiative. The model tests have been carried out in a flume with a sandy dune exposed to a combination of water levels and wave conditions. Different regimes of wave attacks on the sandy/beach dune system have been investigated; in particular, the study provides a unique set of large-scale physical data concerning the storm waves induced dune overwash (Tomasicchio et al. 2011a; Tomasicchio et al.2011b). The effects of various “load parameters” on the dune erosion process generation, including dune recession rates in terms of the retreat of the dune face, Δx, and the eroded volume, ΔV, have been investigated and discussed. The laboratory data sets have been adopted to calibrate and verify the analytical model proposed by Larson et al. (2004) in order to calculate the values of ΔV at specific time intervals. Furthermore, the profile measurements have been used to calibrate and verify the numerical model C-SHORE (Kobayashi et al. 2007) predicting the beach-dune profile modifications over the near-shore region (Tomasicchio et al. 2011a; Tomasicchio et al.2011b).

scholarly journals MODELLING OF A NEARSHORE PLACED SAND MOUND

2012 ◽  
Vol 1 (33) ◽  
pp. 35
Author(s):  
Ernest R. Smith ◽  
Felice D'Alessandro ◽  
Giuseppe Roberto Tomasicchio ◽  
Joseph Z. Gailani
Keyword(s):  
Numerical Model ◽  
Numerical Solutions ◽  
Numerical Models ◽  
Open Water ◽  
Beach Nourishment ◽  
The United States ◽  
Water Levels ◽  
Beach Profile ◽  
Near Shore ◽  
Model C

Nearshore placement of sand is becoming a more popular option in two related types of coastal engineering projects: beach nourishment and inlet dredging. Placing the sand in the nearshore instead of directly on the beach can reduce the costs of a beach nourishment project (Douglass 1995); furthermore, the environmental impact to the beach and dune ecosystem may be perceived to be less for open-water disposal with subsequent migration than for direct placement on the beach. Nearshore placement of sand is also an option in navigation dredging projects for similar reasons. Several design and planning questions relate to the fate of dredged sand placed in the nearshore. Can we economically use profile nourishment, and what is the certainty that a constructed submerged feature will move onshore or remain in place? And if it will move, what is the rate of its movement? Another question concerns how deep material should be placed. In order to answer these questions, together with physical model experiments, several empirical/numerical models have been developed in the past in the United States as a part of the Corps of Engineers ‘Dredging Research Program’ (DRP) (Hands 1991, Larson and Kraus 1992). Hydrodynamic modelling of the nearshore environment has reached a verifiable level of maturity in the last decades as a result of well-defined equations, established numerical solutions and quality laboratory and field data. On the contrary, modelling of sediment transport and beach profile evolution has not yet approached a similar level of accuracy. Most commonly applied models to predict beach profile modifications and to estimate the migration rate of nearshore constructed sand mounds rely on empirical relationships (Douglass 1995). More recently, the numerical model C-SHORE (Kobayashi et al. 2007; Figlus et al. 2011) was developed resulting in simple, practical and accurate code that predicts beach–dune profile evolution over the near-shore region in response to waves, currents and water levels. In the present work, a calibration and verification procedure is considered for the numerical model C-SHORE (Kobayashi et al. 2007) and the empirical model (Douglass 1995).

Stereological Analyses of Hepatocyte Ultrastructure Monitor Arsenic Liver Burdens

1980 ◽  
Vol 38 ◽  
pp. 442-443
Author(s):  
E. M. B. Sorensen ◽  
R. R. Mitchell ◽  
L. L. Graham
Keyword(s):  
Drainage System ◽  
Water Levels ◽  
Ultrastructural Changes ◽  
Hepatocyte Ultrastructure ◽  
Lepomis Cyanellus ◽  
Large Numbers ◽  
Activation Data ◽  
Water Analyses ◽  
Municipal Lake ◽  
Green Sunfish

Endemic freshwater teleosts were collected from a portion of the Navosota River drainage system which had been inadvertently contaminated with arsenic wastes from a firm manufacturing arsenical pesticides and herbicides. At the time of collection these fish were exposed to a concentration of 13.6 ppm arsenic in the water; levels ranged from 1.0 to 20.0 ppm during the four-month period prior. Scale annuli counts and prior water analyses indicated that these fish had been exposed for a lifetime. Neutron activation data showed that Lepomis cyanellus (green sunfish) had accumulated from 6.1 to 64.2 ppm arsenic in the liver, which is the major detoxification organ in arsenic poisoning. Examination of livers for ultrastructural changes revealed the presence of electron dense bodies and large numbers of autophagic vacuoles (AV) and necrotic bodies (NB) (1), as previously observed in this same species following laboratory exposures to sodium arsenate (2). In addition, abnormal lysosomes (AL), necrotic areas (NA), proliferated rough endoplasmic reticulum (RER), and fibrous bodies (FB) were observed. In order to assess whether the extent of these cellular changes was related to the concentration of arsenic in the liver, stereological measurements of the volume and surface densities of changes were compared with levels of arsenic in the livers of fish from both Municipal Lake and an area known to contain no detectable level of arsenic.

AUTOMATIC WATER LEVEL MONITORING WITH IOT AND LPWAN

2019 ◽  
pp. 95-103
Author(s):  
Krum Videnov ◽  
Vanya Stoykova
Keyword(s):  
Water Level ◽  
Real Time ◽  
Early Warning ◽  
Water Sources ◽  
Water Levels ◽  
Water Level Fluctuations ◽  
Level Monitoring ◽  
Water Level Monitoring

Monitoring water levels of lakes, streams, rivers and other water basins is of essential importance and is a popular measurement for a number of different industries and organisations. Remote water level monitoring helps to provide an early warning feature by sending advance alerts when the water level is increased (reaches a certain threshold). The purpose of this report is to present an affordable solution for measuring water levels in water sources using IoT and LPWAN. The assembled system enables recording of water level fluctuations in real time and storing the collected data on a remote database through LoRaWAN for further processing and analysis.

Using groundwater levels and Specific Yield to Estimate the Recharge, South of Erbil, Kurdistan Region, Iraq

2018 ◽  
Vol 7 (4) ◽  
pp. 191
Author(s):  
Sherwan Sh. Qurtas
Keyword(s):  
Unconfined Aquifer ◽  
Middle Part ◽  
Water Levels ◽  
Specific Yield ◽  
Aquifer System ◽  
Groundwater Levels ◽  
Monitoring Wells ◽  
Water Table Fluctuation Method ◽  
Recharge Estimation ◽  
Fluctuation Method

Recharge estimation accurately is crucial to proper groundwater resource management, for the groundwater is dynamic and replenished natural resource. Usually recharge estimation depends on the; the water balance, water levels, and precipitation. This paper is studying the south-middle part of Erbil basin, with the majority of Quaternary sediments, the unconfined aquifer system is dominant, and the unsaturated zone is ranging from 15 to 50 meters, which groundwater levels response is moderate. The purpose of this study is quantification the natural recharge from precipitation. The water table fluctuation method is applied; using groundwater levels data of selected monitoring wells, neighboring meteorological station of the wells, and the specific yield of the aquifers. This method is widely used for its simplicity, scientific, realistic, and direct measurement. The accuracy depends on the how much the determination of specific yield is accurate, accuracy of the data, and the extrapolations of recession of groundwater levels curves of no rain periods. The normal annual precipitation there is 420 mm, the average recharge is 89 mm, and the average specific yield is around 0.03. The data of one water year of 2009 and 2010 has taken for some technical and accuracy reasons.

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