Next Article in Journal
Size/Age Models for Monitoring of the Pink Sea Fan Eunicella verrucosa (Cnidaria: Alcyonacea) and a Case Study Application
Previous Article in Journal
Revisiting Vertical Land Motion and Sea Level Trends in the Northeastern Adriatic Sea Using Satellite Altimetry and Tide Gauge Data
Open AccessFeature PaperArticle

A Modeling Study on the Influence of Sea-Level Rise and Channel Deepening on Estuarine Circulation and Dissolved Oxygen Levels in the Tidal James River, Virginia, USA

by 1 and 2,*
1
The Third Institution of Oceanography, Ministry of Natural Resource, Xiamen 361005, China
2
Virginia Institute of Marine Science, William & Mary, Gloucester Point, VA 23062, USA
*
Author to whom correspondence should be addressed.
J. Mar. Sci. Eng. 2020, 8(11), 950; https://doi.org/10.3390/jmse8110950
Received: 1 October 2020 / Revised: 17 November 2020 / Accepted: 19 November 2020 / Published: 21 November 2020
(This article belongs to the Section Physical Oceanography)
The impact of channel deepening and sea-level rise on the environmental integrity of an estuary is investigated using a three-dimensional hydrodynamic-eutrophication model. The model results show that dissolved oxygen (DO) only experienced minor changes, even when the deep channel was deepened by 3 m in the mesohaline and polyhaline regions of the James River. We found that vertical stratification decreased DO aeration while the estuarine gravitational circulation increased bottom DO exchange. The interactions between these two processes play an important role in modulating DO. The minor change in DO due to channel deepening indicates that the James River is unique as compared with other estuaries. To understand the impact of the hydrodynamic changes on DO, both vertical and horizontal transport timescales represented by water age were used to quantify the changes in hydrodynamic conditions and DO variation, in addition to traditional measures of stratification and circulation. The model results showed that channel deepening led to an increase in both gravitational circulation strength and vertical stratification. Saltwater age decreased and vertical exchange time increased with increases in channel depth. However, these two physical processes can compensate each other, resulting in minor changes in DO. A comparison of the impact of a sea-level rise of 1.0 m with channel deepening scenarios was conducted. As the sea level rises, the vertical transport time decreases slightly while the strength of gravitational circulation weakens due to an increase in mean water depth. Consequently, DO in the estuary experiences a moderate decrease. View Full-Text
Keywords: dissolved oxygen; gravitational circulation; saltwater age; vertical exchange time; channel deepening; sea-level rise; James River dissolved oxygen; gravitational circulation; saltwater age; vertical exchange time; channel deepening; sea-level rise; James River
Show Figures

Figure 1

MDPI and ACS Style

Wang, Y.; Shen, J. A Modeling Study on the Influence of Sea-Level Rise and Channel Deepening on Estuarine Circulation and Dissolved Oxygen Levels in the Tidal James River, Virginia, USA. J. Mar. Sci. Eng. 2020, 8, 950.

Show more citation formats Show less citations formats
Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Article Access Map by Country/Region

1
Search more from Scilit
 
Search
Back to TopTop