Next Article in Journal
Efficiency Evaluation of Water Consumption in a Chinese Province-Level Region Based on Data Envelopment Analysis
Previous Article in Journal
Assessing Environmental Flow Targets Using Pre-Settlement Land Cover: A SWAT Modeling Application
Open AccessArticle

Horizontal Circulation Patterns in a Large Shallow Lake: Taihu Lake, China

1
Department of Hydraulic Engineering, Delft University of Technology, 1, Stevinweg, 2628 CN Delft, The Netherlands
2
Deltares, Boussinesqweg 1, 2629 HV Delft, The Netherlands
3
State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering, Nanjing Hydraulic Research Institute, Nanjing 210029, China
*
Author to whom correspondence should be addressed.
Water 2018, 10(6), 792; https://doi.org/10.3390/w10060792
Received: 9 May 2018 / Revised: 12 June 2018 / Accepted: 13 June 2018 / Published: 15 June 2018
(This article belongs to the Section Hydraulics)
Wind induced hydrodynamic circulations play significant roles in the transport and mixing process of pollutants and nutrients in large shallow lakes, but they have been usually overlooked, while environmental, biological, and ecological aspects of eutrophication problems get the most focus. Herein we use a three-dimensional model, driven by steady/unsteady wind, river discharge, rainfall, evaporation to investigate the spatially heterogeneous, large-scale hydrodynamic circulations and their role in transporting and mixing mechanisms in Taihu Lake. Wind direction and velocity determines the overall hydrodynamic circulation structure, i.e. direction, intensity, and position. A relative stable hydrodynamic circulation pattern has been formed shortly with steady wind (~2 days). Vertical profiles of horizontal velocities are linearly correlated to the relative shallowness of water depth. Volume exchange between subbasins, influenced by wind speed and initial water level, differs due to the complex topography and irregular shape. With unsteady wind, these findings are still valid to a high degree. Vertical variations in hydrodynamic circulation are important in explaining the surface accumulation of algae scums in Meiliang Bay in summers. Vorticity of velocity field, a key indicator of hydrodynamic circulation, is determined by wind direction, bathymetry gradient, and water depth. The maximum change of velocity vorticity happens when wind direction is perpendicular to bathymetry gradient. Furthermore, Lagrangian-based tracer transport is used to estimate emergency pollution leakage impacts, and also to evaluate operational management measurements, such as, the large-scale water transfer. The conclusion is that the large-scale water transfer does not affect the hydrodynamic circulation and volume exchanges between subbasins significantly, but succeeds to transport and then mix the fresh, clean Yangtze River water to a majority area of Taihu Lake. View Full-Text
Keywords: hydrodynamic circulation; large shallow lakes; vorticity of velocity; wind-induced current; Taihu Lake hydrodynamic circulation; large shallow lakes; vorticity of velocity; wind-induced current; Taihu Lake
Show Figures

Figure 1

MDPI and ACS Style

Liu, S.; Ye, Q.; Wu, S.; Stive, M.J.F. Horizontal Circulation Patterns in a Large Shallow Lake: Taihu Lake, China. Water 2018, 10, 792.

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
Back to TopTop