scholarly journals Response of Water Environment to Land Reclamation in Jiaozhou Bay, China Over the Last 150 Years

2021 ◽  
Vol 8 ◽  
Author(s):  
Chunyang Xu ◽  
Chunyan Zhou ◽  
Kao Ma ◽  
Peng Wang ◽  
Xihe Yue
Keyword(s):  
Numerical Model ◽  
Residence Time ◽  
Water Exchange ◽  
Land Reclamation ◽  
Jiaozhou Bay ◽  
Water Environment ◽  
Pollutant Transport ◽  
Tidal Flats ◽  
Tidal Prism

Jiaozhou Bay (JZB), located at Qingdao City, north China, is a semi-enclosed shallow bay that has undergone large-scale land reclamation and is suffering from a deteriorated water environment. Long-term evolution of JZB with respect of coastline, tidal prism, tidal dynamics, water-exchange capacity, and pollutant transport from 1863 to 2020 was investigated in this paper, using remote sensing images, historical charts, and a numerical model. The JZB was predominated by natural evolution from 1863 to 1935, during which the coastline barely changed. Thereafter, human intervention became intense and more and more natural tidal flats were replaced by salt ponds, aquaculture area, and reclamation very quickly. As a result, tidal prism, area of tidal flats, and area of JZB decreased sharply by 0.290 km3, 182 km2, and 223 km2, respectively, from 1935 to 2020, corresponding to annual decreasing rates being of 123 times, 10 times, 12 times, respectively, as that of before 1935. A numerical model showed that the residual current in JZB tended to be weaker due to the change of coastline and bathymetry, which is not favoring the water-exchange and pollutant transport, especially in the northeast of JZB. The basin residence time increased from 15.5 days in 1935 to 17.6 days in 2020, because of weaker residual tidal current and smaller tidal prism. Local residence time increased significantly near the area with large land reclamation, especially in the northeast and west of JZB. Distribution of dissolved inorganic nitrogen (DIN), in each year, which is the dominant pollutant in JZB, indicated higher DIN concentration and weaker transport along with reclamation. The research on JZB evolution over the last 150 years can provide useful suggestions for the decision-makers of the local government to improve the marine ecosystem. The systematic method to investigate long-term water environment evolution of JZB can be used to study other semi-closed bays.

Research on Water Environment Problem for Landscape Design of Waterfront Districts

2011 ◽  
Vol 90-93 ◽  
pp. 2414-2417 ◽  
Author(s):  
Yuan Yuan Chen ◽  
Xue Ping Gao ◽  
Chen Zhang
Keyword(s):  
System Theory ◽  
Numerical Model ◽  
Water Exchange ◽  
Water Environment ◽  
Landscape Design ◽  
Term Operation ◽  
Environment Problem ◽  
3D Numerical Model ◽  
Model Water

During the landscape design of the waterfront district, the designers often lack of full attention to the water environment problems and lack of system theory knowledge, so that some water environment problems (poor hydrodynamic, deteriorated water quality et al) will be emerged during long term operation of water landscape. For avoiding above problems, numerical simulation can be used in studies of water environment problems during the process of the landscape design. For explaining the application of the 3D numerical model, water environment problems above are studied in the Qilihai Lagoon, including flow field, water exchange and sediment deposition. The numerical model is tested validly by the measured dates.

Simulation of water exchange in Jiaozhou Bay by average residence time approach

2004 ◽  
Vol 61 (1) ◽  
pp. 25-35 ◽  
Author(s):  
Zhe Liu ◽  
Hao Wei ◽  
Guangshan Liu ◽  
Jing Zhang
Keyword(s):  
Residence Time ◽  
Water Exchange ◽  
Jiaozhou Bay ◽  
Average Residence Time

Model Study of the Water Exchange in a Shallow Bay

2013 ◽  
Vol 726-731 ◽  
pp. 3439-3442
Author(s):  
Hao Liu ◽  
Dan Luo ◽  
Hong Xuan Kang ◽  
Bao Shu Yin
Keyword(s):  
Water Exchange ◽  
Circulation Model ◽  
Tidal Prism ◽  
3 Dimensional ◽  
Model Study ◽  
Term Variation ◽  
Enclosed Bay ◽  
Coastal Circulation Model ◽  
Shallow Bay

Both the tidal prism and the water exchange duration can be used as the index of examining the residence time of the pollutants in a semi-enclosed bay, and it is significant to predict the long-term variation of water quality. A 3-dimensional coastal circulation model is used to reproduce the tidal regime in the Shenhu Bay. Simulated tidal currents are examined first, and the then the tidal prism is also compared to observations. Based on the validated simulations, the water exchange duration is further estimated by means of the numerical experiment. The simulations show that the half-exchange and 80%-exchange time are about 14 and 30 d, respectively.

SATELLITE DATA FOR INVESTIGATION OF RECENT STATE AND PROCESSES IN THE SIVASH BAY

2017 ◽  
Author(s):  
Ekaterina Shchurova ◽  
Ekaterina Shchurova ◽  
Rimma Stanichnaya ◽  
Rimma Stanichnaya ◽  
Sergey Stanichny ◽  
...  
Keyword(s):  
Satellite Data ◽  
Water Exchange ◽  
High Salinity ◽  
Meteorological Data ◽  
Sea Surface ◽  
Azov Sea ◽  
Seasonal Wind ◽  
Ice Regime ◽  
Very High

Sivash bay is the shallow-water lagoon of the Azov Sea. Restricted water exchange and high evaporation form Sivash as the basin with very high salinity. This factor leads to different from the Azov Sea thermal and ice regimes of Sivash. Maine aim of the study presented to investigate recent state and changes of the characteristics and processes in the basin using satellite data. Landsat scanners TM, ETM+, OLI, TIRS together with MODIS and AVHRR were used. Additionally NOMADS NOAA and MERRA meteorological data were analyzed. The next topics are discussed in the work: 1. Changes of the sea surface temperature, ice regime and relation with salinity. 2. Coastal line transformation – long term and seasonal, wind impact. 3. Manifestation of the Azov waters intrusions through the Arabat spit, preferable wind conditions.

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.

Mathematical modeling of fluid movement inside the eyeball during intravitreal injection

2021 ◽  
pp. 106-109
Author(s):  
D.V. Lipatov ◽  
◽  
S.A. Skladchikov ◽  
N.P. Savenkova ◽  
V.V. Novoderezkin ◽  
...  
Keyword(s):  
Mathematical Modeling ◽  
Mathematical Model ◽  
Residence Time ◽  
Complex Structure ◽  
Posterior Vitreous Detachment ◽  
Vitreous Body ◽  
Complete Removal ◽  
Intravitreal Injections ◽  
The World

Background. The avalanche-like growth of intravitreal injections in the world has significantly increased interest in the hemodynamics of the processes that occur in the eye when a drug is injected into the vitreous cavity. Every year, the number of intravitreally used drugs and promising areas in which they can be used is growing. This also applies to the creation of new combined medicines and the development of drugs with a long-term therapeutic effect. Aims. Create mathematical model of eyeball to evaluate the movement of the drug substance in it; to estimate the time of the drug's presence in the eye cavity before its complete removal, to characterize the ways of its removal from the eye cavity; to assess the significance of posterior vitreous detachment during the time when the drug is present in the eye cavity; to evaluate the effect on the hydrodynamics of the depth of drug administration. Results. When the drug is administered closer to the center of the eyeball, its residence time increases in comparison with the parietal administration. With a complete posterior detachment of the vitreous body, the time of finding the drug in the eye is prolonged compared to its absence. The obtained results of mathematical modeling of the movement of the drug administered intravitreally cannot be mechanically transferred to the human eye, due to the more complex structure of the latter. Key words: intravitreal injections, vitreous body, mathematic computing.

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