scholarly journals Numerical simulation of three-dimensional hydrodynamic characteristics and pollutant diffusion behavior by ROMS model

2020 ◽  
Author(s):  
Jing Ren ◽  
Chazhong Ge ◽  
Chunxu Hao ◽  
Rui Hu ◽  
Kefu Cui ◽  
...  
Keyword(s):  
Tidal Current ◽  
Water Exchange ◽  
Current Model ◽  
Three Dimensional ◽  
Control Unit ◽  
Distribution Patterns ◽  
Hydrodynamic Characteristics ◽  
Bohai Bay ◽  
Offshore Area ◽  
Roms Model

Abstract Based on the ROMs model, a three-dimensional hydrodynamic model and a convection diffusion model are built in this paper. The three-dimensional tidal current model is intended to reflect the distribution characteristics of the tidal level and the flow field of water with different depths of the Bohai Bay. On this basis, water exchange correlation matrix is adopted to analyze the water exchange characteristics of the offshore area of Binzhou City in the offshore planning functional area of the Bohai Bay. Considering the functional planning of offshore area of Binzhou city, the paper simulates how COD and NH4 + -N in the water discharged from the sewage outfall of the city migrate and disperse under tidal current. In this way, the paper concludes the concentration distribution patterns of pollutants at different times. The results serve as basis and reference to delimitation of environmental management and control unit demarcation in Binzhou nearshore.

Investigation of Three Dimensional Tidal Stream Energy in Surrounding Water Areas of ZTD, China

2013 ◽  
Vol 774-776 ◽  
pp. 262-266
Author(s):  
Bing Chen Liang ◽  
Tao Tao Zhang ◽  
Hong Da Shi
Keyword(s):  
Numerical Modeling ◽  
Energy Density ◽  
Tidal Current ◽  
Current Model ◽  
Three Dimensional ◽  
Coastal Zones ◽  
Surrounding Water ◽  
Tidal Current Velocity ◽  
Tidal Stream ◽  
Tidal Stream Energy

In the present work, the tidal stream energy in surrounding coastal zones of ZTD is calculated. The tidal current velocity is gotten by three dimensional numerical modeling. The tidal current model is validated by measurement of tidal current observed in 4 points surrounding ZTD. The numerical results given by the tidal current model already shows that: the tidal current velocities given by the model agree with the measured velocities generally. The characteristics of tidal currents around ZTD are analyzed and the following tidal stream energy density is calculated. The maximum tidal stream energy flux of unit width occurs around the middle locations of ZTD southern areas.

MESSINE, a Parametric Three-Dimensional Eddy Current Model

2000 ◽  
Vol 12 (1) ◽  
pp. 65-86 ◽  
Author(s):  
R. La ◽  
B. Benoist ◽  
B. de Barmon ◽  
M. Talvard ◽  
R. Lengelle ◽  
...  
Keyword(s):  
Eddy Current ◽  
Current Model ◽  
Three Dimensional

scholarly journals Numerical simulation of the impact of an integrated renovation project on the Maowei Sea hydrodynamic environment

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Cui Wang ◽  
Ling Cai ◽  
Yaojian Wu ◽  
Yurong Ouyang
Keyword(s):  
Water Exchange ◽  
Land Reclamation ◽  
Three Dimensional ◽  
Exchange Capacity ◽  
Reclamation Project ◽  
Hydrodynamic Environment ◽  
Sea Area ◽  
Water Quality Models ◽  
The Impact ◽  
Main Factor

AbstractIntegrated renovation projects are important for marine ecological environment protection. Three-dimensional hydrodynamics and water quality models are developed for the Maowei Sea to assess the hydrodynamic environment base on the MIKE3 software with high resolution meshes. The results showed that the flow velocity changed minimally after the project, decreasing by approximately 0.12 m/s in the east of the Maowei Sea area and increasing by approximately 0.01 m/s in the northeast of the Shajing Port. The decrease in tidal prism (~ 2.66 × 106 m3) was attributed to land reclamation, and accounted for just 0.86% of the pre-project level. The water exchange half-life increased by approximately 1 day, implying a slightly reduced water exchange capacity. Siltation occurred mainly in the reclamation and dredging areas, amounting to back-silting of approximately 2 cm/year. Reclamation project is the main factor causing the decrease of tidal volume and weakening the hydrodynamics in Maowei Sea. Adaptive management is necessary for such a comprehensive regulation project. According to the result, we suggest that reclamation works should strictly prohibit and dredging schemes should optimize in the subsequent regulation works.

scholarly journals Morphodynamic Evolution of a Nourished Beach with Artificial Sandbars: Field Observations and Numerical Modeling

2021 ◽  
Vol 9 (3) ◽  
pp. 245
Author(s):  
Cuiping Kuang ◽  
Xuejian Han ◽  
Jiabo Zhang ◽  
Qingping Zou ◽  
Boling Dong
Keyword(s):  
Sediment Transport ◽  
Tidal Current ◽  
Model Simulation ◽  
Morphological Changes ◽  
Current Model ◽  
Beach Nourishment ◽  
Tidal Range ◽  
Coastal Protection ◽  
Field Observations ◽  
One Year

Beach nourishment, a common practice to replenish an eroded beach face with filling sand, has become increasingly popular as an environmentally friendly soft engineering measure to tackle coastal erosion. In this study, three 200 m long offshore submerged sandbars were placed about 200 m from the shore in August 2017 for both coastal protection and beach nourishment at Shanhai Pass, Bohai Sea, northeastern China. A series of 21 beach profiles were collected from August 2017 to July 2018 to monitor the morphological changes of the nourished beach. Field observations of wave and tide levels were conducted for one year and tidal current for 25 h, respectively. To investigate the spatial-temporal responses of hydrodynamics, sediment transport, and morphology to the presence of three artificial submerged sandbars, a two-dimensional depth-averaged (2DH) multi-fraction sediment transport and morphological model were coupled with wave and current model and implemented over a spatially varying nested grid. The model results compare well with the field observations of hydrodynamics and morphological changes. The tidal range was around 1.0 m and the waves predominately came from the south-south-east (SSE) direction in the study area. The observed and predicted beach profiles indicate that the sandbars moved onshore and the morphology experienced drastic changes immediately after the introduction of sandbars and reached an equilibrium state in about one year. The morphological change was mainly driven by waves. Under the influences of the prevailing waves and the longshore drift toward the northeast, the coastline on the leeside of the sandbars advanced seaward by 35 m maximally while the rest adjacent coastline retreated severely by 44 m maximally within August 2017–July 2018. The model results demonstrate that the three sandbars have little effect on the tidal current but attenuate the incoming wave significantly. As a result, the medium-coarse sand of sandbars is transported onshore and the background silt is mainly transported offshore and partly in the longshore direction toward the northeast. The 2- and 5-year model simulation results further indicate that shoreline salient may form behind the sandbars and protrude offshore enough to reach the sandbars, similar to the tombolo behind the breakwater.

scholarly journals Spatiotemporal Analysis of COVID-19 Spread with Emerging Hotspot Analysis and Space–Time Cube Models in East Java, Indonesia

2021 ◽  
Vol 10 (3) ◽  
pp. 133
Author(s):  
Purwanto Purwanto ◽  
Sugeng Utaya ◽  
Budi Handoyo ◽  
Syamsul Bachri ◽  
Ike Sari Astuti ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Distribution Patterns ◽  
Spatiotemporal Analysis ◽  
Space Time ◽  
Road Density ◽  
Hotspot Analysis ◽  
Spatiotemporal Information ◽  
Depth Analysis ◽  
Analysis Models ◽  
Oscillating Patterns

In this research, we analyzed COVID-19 distribution patterns based on hotspots and space–time cubes (STC) in East Java, Indonesia. The data were collected based on the East Java COVID-19 Radar report results from a four-month period, namely March, April, May, and June 2020. Hour, day, and date information were used as the basis of the analysis. We used two spatial analysis models: the emerging hotspot analysis and STC. Both techniques allow us to identify the hotspot cluster temporally. Three-dimensional visualizations can be used to determine the direction of spread of COVID-19 hotspots. The results showed that the spread of COVID-19 throughout East Java was centered in Surabaya, then mostly spread towards suburban areas and other cities. An emerging hotspot analysis was carried out to identify the patterns of COVID-19 hotspots in each bin. Both cities featured oscillating patterns and sporadic hotspots that accumulated over four months. This pattern indicates that newly infected patients always follow the recovery of previous COVID-19 patients and that the increase in the number of positive patients is higher when compared to patients who recover. The monthly hotspot analysis results yielded detailed COVID-19 spatiotemporal information and facilitated more in-depth analysis of events and policies in each location/time bin. The COVID-19 hotspot pattern in East Java, visually speaking, has an amoeba-like pattern. Many positive cases tend to be close to the city, in places with high road density, near trade and business facilities, financial storage, transportation, entertainment, and food venues. Determining the spatial and temporal resolution for the STC model is crucial because it affects the level of detail for the information of endemic disease distribution and is important for the emerging hotspot analysis results. We believe that similar research is still rare in Indonesia, although it has been done elsewhere, in different contexts and focuses.

ACOUSTIC THREE-DIMENSIONAL EFFECTS AROUND THE TAIWAN STRAIT: COMPUTATIONAL RESULTS

1999 ◽  
Vol 07 (01) ◽  
pp. 15-26 ◽  
Author(s):  
CHI-FANG CHEN ◽  
JANG-JIA LIN ◽  
DING LEE
Keyword(s):  
Field Data ◽  
Bottom Topography ◽  
Three Dimensional ◽  
Propagation Model ◽  
Computational Results ◽  
Submarine Canyons ◽  
Offshore Area ◽  
Ocean Environment ◽  
The Taiwan Strait ◽  
Good Agreement

A set of experiments were performed in the offshore area off the coasts of Taiwan and three-dimensional (3-D) measurements recorded. The 3-D effect on underwater propagation due to azimuthal variation of bottom topography is studied for the offshore regions southwest of Taiwan, where submarine canyons exist. A 3-D acoustic propagation model, FOR3D, is used to detect the 3-D effect. Computational results show that the 3-D effect is more prominent along the axis of the canyon than across it. Calculations show a very good agreement with field data, which indicate that the 3-D effect exists in this realistic ocean environment.

An eddy-current model for three-dimensional inversion

1986 ◽  
Vol 22 (4) ◽  
pp. 282-291 ◽  
Author(s):  
H. Sabbagh ◽  
L. Sabbagh
Keyword(s):  
Eddy Current ◽  
Current Model ◽  
Three Dimensional

scholarly journals Diversity and distribution patterns of the Oligocene and Miocene decapod crustaceans (Crustacea: Malacostraca) of the Western and Central Paratethys

2016 ◽  
Vol 67 (5) ◽  
pp. 471-494 ◽  
Author(s):  
Matúš Hyžný
Keyword(s):  
Spatial Scales ◽  
Three Dimensional ◽  
Decapod Crustacean ◽  
Distribution Patterns ◽  
Mediterranean Area ◽  
Homogeneous Distribution ◽  
Decapod Crustaceans ◽  
Central Paratethys ◽  
The North ◽  
Marine Habitats

AbstractDecapod associations have been significant components of marine habitats throughout the Cenozoic when the major diversification of the group occurred. In this respect, the circum-Mediterranean area is of particular interest due to its complex palaeogeographic history. During the Oligo-Miocene, it was divided in two major areas, Mediterranean and Paratethys. Decapod crustaceans from the Paratethys Sea have been reported in the literature since the 19thcentury, but only recent research advances allow evaluation of the diversity and distribution patterns of the group. Altogether 176 species-level taxa have been identified from the Oligocene and Miocene of the Western and Central Paratethys. Using the three-dimensional NMDS analysis, the composition of decapod crustacean faunas of the Paratethys shows significant differences through time. The Ottnangian and Karpatian decapod associations were similar to each other both taxonomically and in the mode of preservation, and they differed taxonomically from the Badenian ones. The Early Badenian assemblages also differed taxonomically from the Late Badenian ones. The time factor, including speciation, immigration from other provinces and/or (local or global) extinction, can explain temporal differences among assemblages within the same environment. High decapod diversity during the Badenian was correlated with the presence of reefal settings. The Badenian was the time with the highest decapod diversity, which can, however, be a consequence of undersampling of other time slices. Whereas the Ottnangian and Karpatian decapod assemblages are preserved virtually exclusively in the siliciclastic “Schlier”-type facies that originated in non-reefal offshore environments, carbonate sedimentation and the presence of reefal environments during the Badenian in the Central Paratethys promoted thriving of more diverse reef-associated assemblages. In general, Paratethyan decapods exhibited homogeneous distribution during the Oligo-Miocene among the basins in the Paratethys. Based on the co-occurrence of certain decapod species, migration between the Paratethys and the North Sea during the Early Miocene probably occurred via the Rhine Graben. At larger spatial scales, our results suggest that the circum-Mediterranean marine decapod taxa migrated in an easterly direction during the Oligocene and/or Miocene, establishing present-day decapod communities in the Indo-West Pacific.

Sign in / Sign up

Export Citation Format

Share Document