scholarly journals Beach Response to a Shoreface Nourishment (Aveiro, Portugal)

2021 ◽  
Vol 9 (10) ◽  
pp. 1112
Author(s):  
Diogo Mendes ◽  
Joaquim Pais-Barbosa ◽  
Paulo Baptista ◽  
Paulo A. Silva ◽  
Cristina Bernardes ◽  
...  
Keyword(s):  
Shallow Water ◽  
Case Studies ◽  
Spatial Position ◽  
Monitoring Programme ◽  
Storm Events ◽  
Coastal Monitoring ◽  
Volume Increase ◽  
One Year ◽  
Beach Volume ◽  
Water Depths

In Aveiro (NW coast of Portugal), a coastal monitoring programme was carried out in sequence of a shoreface nourishment intervention (over than 2 M m3) performed in 2020. In this programme, almost one year of biweekly subaerial topographies and quarterly bathymetric surveys have been collected along a 10 km coastal stretch between June 2020 and June 2021. In this study, topographic and bathymetric surveys were analysed to assess the expectation that if the shoreface nourishment is located in sufficiently shallow water depths, its landward movement will feed adjacent beaches and, consequently, increase the subaerial beach volume. Results show that the subaerial beach volume is well correlated with the 1.05 m (above MSL) isoline displacement through time. While the seaward limit of the shoreface nourishment moved landwards about 200 m, the shoreline proxy (isoline of 1.05 m) displayed a maximum seaward displacement of 60 m. The displacement of the shoreline proxy was highly variable in space, along the 10 km coastal stretch, and also in time, during storm events. During such events, both landward and seawards displacement of the shoreline proxy took place, depending on the spatial position. Moreover, while beaches close to the initial shoreface nourishment intervention displayed faster accretion patterns than those located farther away, the well-defined onshore movement of the shoreface nourishment did not result in a considerable beach volume increase. The achieved results were also compared against case studies of shoreface nourishments with similar volumes performed worldwide.

MAPPING TIDAL CURRENTS AND RESIDUAL CURRENTS BY USE OF COASTAL ACOUSTIC TOMOGRAPHY

2017 ◽  
Author(s):  
Xiao-Hua Zhu ◽  
Xiao-Hua Zhu ◽  
Ze-Nan Zhu ◽  
Ze-Nan Zhu ◽  
Xinyu Guo ◽  
...  
Keyword(s):  
Shallow Water ◽  
Shallow Water Equations ◽  
Mean Amplitude ◽  
Momentum Equation ◽  
Tidal Currents ◽  
Acoustic Tomography ◽  
Mean Values ◽  
Residual Currents ◽  
Water Depths ◽  
Deep Area

A coastal acoustic tomography (CAT) experiment for mapping the tidal currents in the Zhitouyang Bay was successfully carried out with seven acoustic stations during July 12 to 13, 2009. The horizontal distributions of tidal current in the tomography domain are calculated by the inverse analysis in which the travel time differences for sound traveling reciprocally are used as data. Spatial mean amplitude ratios M2 : M4 : M6 are 1.00 : 0.15 : 0.11. The shallow-water equations are used to analyze the generation mechanisms of M4 and M6. In the deep area, velocity amplitudes of M4 measured by CAT agree well with those of M4 predicted by the advection terms in the shallow water equations, indicating that M4 in the deep area where water depths are larger than 60 m is predominantly generated by the advection terms. M6 measured by CAT and M6 predicted by the nonlinear quadratic bottom friction terms agree well in the area where water depths are less than 20 m, indicating that friction mechanisms are predominant for generating M6 in the shallow area. Dynamic analysis of the residual currents using the tidally averaged momentum equation shows that spatial mean values of the horizontal pressure gradient due to residual sea level and of the advection of residual currents together contribute about 75% of the spatial mean values of the advection by the tidal currents, indicating that residual currents in this bay are induced mainly by the nonlinear effects of tidal currents.

scholarly journals Population structures among epiphytal foraminiferal communities, Nevis, West Indies

2008 ◽  
Vol 27 (1) ◽  
pp. 63-73 ◽  
Author(s):  
Brent Wilson
Keyword(s):  
Time Series ◽  
Shallow Water ◽  
West Indies ◽  
Septic Tank ◽  
Amphistegina Gibbosa ◽  
Species Abundances ◽  
Population Structures ◽  
Logarithmic Series ◽  
One Year ◽  
Structure Investigations

Abstract. The taxocene of live epiphytal foraminifera was for one year monitored monthly on six phytal substrates in shallow water (<1 m) in two bays around Nevis, NE Caribbean Sea. Mosquito Bay was subject to a nutrient flux from a leaking septic tank. Long Haul Bay was comparatively undeveloped. SHE Community Structure Investigations (SHECSIs) revealed that the populations on five plants had logarithmic series distributions of species abundances, the slopes of lnS vs. lnE for these five time-series being within −1±0.3. In three time-series, they were within −1±0.05.Cluster analysis of twenty-five sediment samples in shallow water (<3 m) indicates that Nevis is largely surrounded by a single thanatacoenosis, for which SHECSI indicates a logarithmic series population structure. However, it is not possible to reconstruct perfectly the epiphytal population from the sediment thanatacoenosis. The thanatacoenosis included 40% allochthonous Amphistegina gibbosa, Archaias angulatus and Asterigerina carinata, washed in from offshore reefs, and few planorbulinids, although the latter dominates the biocoenosis on seagrass leaves in the backreef.

scholarly journals Measuring the Impact of Observations on the Predictability of the Kuroshio Extension in a Shallow-Water Model

2012 ◽  
Vol 42 (1) ◽  
pp. 3-17 ◽  
Author(s):  
Werner Kramer ◽  
Henk A. Dijkstra ◽  
Stefano Pierini ◽  
Peter Jan van Leeuwen
Keyword(s):  
Shallow Water ◽  
Particle Filtering ◽  
Predictive Power ◽  
Kuroshio Extension ◽  
Water Model ◽  
Ensemble Prediction ◽  
Shallow Water Model ◽  
One Year ◽  
The Impact ◽  
The Kuroshio

Abstract In this paper, sequential importance sampling is used to assess the impact of observations on an ensemble prediction for the decadal path transitions of the Kuroshio Extension. This particle-filtering approach gives access to the probability density of the state vector, which allows the predictive power—an entropy-based measure—of the ensemble prediction to be determined. The proposed setup makes use of an ensemble that, at each time, samples the climatological probability distribution. Then, in a postprocessing step, the impact of different sets of observations is measured by the increase in predictive power of the ensemble over the climatological signal during one year. The method is applied in an identical-twin experiment for the Kuroshio Extension using a reduced-gravity shallow-water model. This study investigates the impact of assimilating velocity observations from different locations during the elongated and the contracted meandering states of the Kuroshio Extension. Optimal observation locations correspond to regions with strong potential vorticity gradients. For the elongated state the optimal location is in the first meander of the Kuroshio Extension. During the contracted state it is located south of Japan, where the Kuroshio separates from the coast.

scholarly journals Balance Nutrition Messages Are Still Implemented in Preschools One Year Postintervention: Case Studies in Subang District, West Java, Indonesia

2020 ◽  
Vol 66 (Supplement) ◽  
pp. S155-S161
Author(s):  
Avita A USFAR ◽  
Ginarti BUDIMAN ◽  
MC Phan Ju LAN ◽  
Akhir RIYANTI ◽  
Visca NURYANTO
Keyword(s):  
Case Studies ◽  
West Java ◽  
Nutrition Messages ◽  
One Year

scholarly journals Genesis and Evolution of Ferromanganese Crusts from the Summit of Rio Grande Rise, Southwest Atlantic Ocean

Minerals ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 349 ◽  
Author(s):  
Mariana Benites ◽  
James R. Hein ◽  
Kira Mizell ◽  
Terrence Blackburn ◽  
Luigi Jovane
Keyword(s):  
Atlantic Ocean ◽  
Shallow Water ◽  
Water Column ◽  
Rio Grande ◽  
Intermediate Water ◽  
Mode Water ◽  
Southwest Atlantic ◽  
Ferromanganese Crusts ◽  
Depositional Processes ◽  
Water Depths

The Rio Grande Rise (RGR) is a large elevation in the Atlantic Ocean and known to host potential mineral resources of ferromanganese crusts (Fe–Mn), but no investigation into their general characteristics have been made in detail. Here, we investigate the chemical and mineralogical composition, growth rates and ages of initiation, and phosphatization of relatively shallow-water (650–825 m) Fe–Mn crusts dredged from the summit of RGR by using computed tomography, X-ray diffraction, 87Sr/86Sr ratios, U–Th isotopes, and various analytical techniques to determine their chemical composition. Fe–Mn crusts from RGR have two distinct generations. The older one has an estimated age of initiation around 48–55 Ma and was extensively affected by post-depositional processes under suboxic conditions resulting in phosphatization during the Miocene (from 20 to 6.8 Ma). As a result, the older generation shows characteristics of diagenetic Fe–Mn deposits, such as low Fe/Mn ratios (mean 0.52), high Mn, Ni, and Li contents and the presence of a 10 Å phyllomanganate, combined with the highest P content among crusts (up to 7.7 wt %). The younger generation is typical of hydrogenetic crusts formed under oxic conditions, with a mean Fe/Mn ratio of 0.75 and mean Co content of 0.66 wt %, and has the highest mean contents of Bi, Nb, Ni, Te, Rh, Ru, and Pt among crusts formed elsewhere. The regeneration of nutrients from local biological productivity in the water column is the main source of metals to crusts, providing mainly metals that regenerate rapidly in the water column and are made available at relatively shallow water depths (Ni, As, V, and Cd), at the expense of metals of slower regeneration (Si and Cu). Additionally, important contributions of nutrients may derive from various water masses, especially the South Atlantic Mode Water and Antarctic Intermediate Water (AAIW). Bulk Fe–Mn crusts from the summit of RGR plateau are generally depleted in metals considered of greatest economic interest in crusts like Co, REE, Mo, Te, and Zr, but are the most enriched in the critical metals Ni and Li compared to other crusts. Further investigations are warranted on Fe–Mn crusts from deeper-water depths along the RGR plateau and surrounding areas, which would less likely be affected by phosphatization.

Pretreatment of Textile Processing Wastewaters

1990 ◽  
Vol 22 (9) ◽  
pp. 17-24 ◽  
Author(s):  
O. Tünay ◽  
O. Tameroǧlu ◽  
N. Baykal ◽  
F. Afşarünal ◽  
E. Ödemiş
Keyword(s):  
Case Studies ◽  
Biological Treatment ◽  
Treatment Plant ◽  
Textile Processing ◽  
Processing Industry ◽  
Chemical Coagulation ◽  
Actual Treatment ◽  
Investment Cost ◽  
Processing Plants ◽  
One Year

In this paper, the pretreatment approaches in the textile processing industry are discussed and two case studies which have been carried out in two textile processing plants are delineated. Case studies include the phases of process and pollution profiles, treatability study, conceptual design and evaluation of one-year actual treatment plant performances. One of the treatment schemes applied was chemical coagulation while the other was activated sludge. Therefore a comparison of two main types of pretreatment has been realised. Results indicate that biological treatment is more efficient and reliable in terms of organic matter removal as compared to chemical coagulation. Comparisons of cost of initial investment, cost and ease of operation, and sludge production are also made and discussed.

Estimation of annual pollutant loadings in two small catchments and examination of their differences caused by regional properties

2006 ◽  
Vol 53 (2) ◽  
pp. 33-44 ◽  
Author(s):  
S. Fujii ◽  
M. Moriya ◽  
P. Songprasert ◽  
H. Ihara
Keyword(s):  
River Basin ◽  
High Frequency ◽  
Storm Event ◽  
Precipitation Pattern ◽  
Storm Events ◽  
Rainfall Events ◽  
Survey Results ◽  
One Year ◽  
Small Catchments

A series of runoff surveys was conducted for more than one year in two small catchments of the Kamo River basin (75.4 km2) and the Takano River basin (66.8 km2) in Kyoto, Japan, which adjoin each other, and may have the same precipitation pattern. The investigation consisted of a high-frequency periodic survey, a long-term regular survey and a storm event survey. The survey results were compared with the regional properties of the basins, and the following results were obtained. (1) Pollutant loadings were successfully estimated as two portions of base discharge and storm events discharge from the survey results. (2) Estimated annual loading of the sites was 2.9–4.5, 1.3–1.8, 17–27, 1.3–2.2, 0.076–0.97 t/km2/y, respectively for CODMn, DOC, SS, TN and TP. (3) 52–53% of the whole flow, which was caused by rainfall events, conveyed 81–87, 68–73, 92–95, 64–67, 76–81% of the whole loading, respectively for CODMn, DOC, SS, TN and TP. (4) Differences of regional properties in two basins cause different runoff patterns, but the differences in runoff patterns also depend on the rainfall patterns. In general, a more urbanized basin receives early and strong influence of precipitation on the storm event runoff.

Natural succession of macroalgal-dominated epibenthic assemblages at different water depths and after transplantation from deep to shallow water on Spitsbergen

Polar Biology ◽  
2008 ◽  
Vol 31 (10) ◽  
pp. 1191-1203 ◽  
Author(s):  
Anna Fricke ◽  
Markus Molis ◽  
Christian Wiencke ◽  
Nelson Valdivia ◽  
Annelise S. Chapman
Keyword(s):  
Shallow Water ◽  
Natural Succession ◽  
Water Depths

The pycnogonid fauna (Pycnogonida, Arthropoda) of the Tayrona National Park and adjoining areas on the Caribbean coast of Colombia

Zootaxa ◽  
2009 ◽  
Vol 2319 (1) ◽  
pp. 1-138 ◽  
Author(s):  
HANS-GEORG MÜLLER ◽  
FRANZ KRAPP
Keyword(s):  
Species Composition ◽  
Shallow Water ◽  
Brown Algae ◽  
National Park ◽  
Caribbean Sea ◽  
Coralline Algae ◽  
Number Of Species ◽  
Sargassum Cymosum ◽  
The Caribbean ◽  
One Year

A complete account on the shallow-water Pycnogonida known up to now from depths between 0-30 m in the Caribbean Sea of Colombia is presented. Almost all the information included herein is based upon the data obtained by the first author during a 14-month fieldwork programme carried out at the Instituto de Investigaciones Marinas de Punta de Betin (INVEMAR) in Santa Marta, Magdalena department.        5312 specimens of 50 species, including 7 species new to science in the genera Ammothella (2), Tanystylum (1), Callipallene (2), Anoplodactylus (1) and Endeis (1), were collected from 179 samples at 45 stations. The area covered by this research ranges in the west from Punta Brava, just near the airport of Santa Marta, eastward to Punta el Diamante at the eastern border of the Tayrona National Park, extending over about 70 km of coastline. Additionally, 6 other pycnogonid species reported previously from outside this area, which are also known from the Caribbean Sea of Colombia are briefly reviewed.        The species from the Santa Marta area are described in detail, with comments on their intraspecific affinities, habitat preference, phenology, vertical distribution and geographic distribution.        Quantitative samples were taken approximately monthly at three stations at Bahía Concha over one year to compare the species composition from substrata of different structure, namely stands of the brown algae Digenia simplex and Sargassum cymosum on a dead Porites reef, and a stand of Thalassia testudinum, which was interspersed with dead coral substratum and coralline algae.        Number of species at all of these stations was found to be similar and species composition of the two species of brown algae almost identical. Achelia sawayai was by far the most numerous species in samples of Digenia simplex, whereas Tanystylum acuminatum and T. isabellae were most numerous in Sargassum cymosum. Species composition in Thalassia was rather different from that of the algal vegetation. In Thalassia, Ammothella appendiculata and A. exornata were the commonest species which were not found in Digenia and Sargassum.        No evidence was found that reproduction of pycnogonids in this tropical area is limited to certain periods of the year. One might presume a shorter reproductive cycle only for Tanystylum acuminatum, because ovigerous males appeared at the end of the rainy season in December and remained until May, therefore for most of the duration of the dry season.        Generally, number of species and specimens collected at all three quantitative sampling stations was rather variable from month to month, implying a heterogenous distribution within the substratum, which surely depend on the distribution of their food.        Zoogeographic patterns are at present almost impossible to interpret, owing to the limited information available on the distribution of most species. However, it can be seen that the Santa Marta region has a very high number of shallow-water pycnogonid species, compared with the fauna of Panamá and Belize, where only 34 and 33 species have been recorded, respectively. However, the high number of species found in the Santa Marta area may be a result of the extensive collecting efforts made over a period of more than one year.

Sign in / Sign up

Export Citation Format

Share Document