title: Water age prediction and its potential impacts on water quality using a hydrodynamic model for Poyang Lake, China.
abstract: The water quality in Poyang Lake, the largest freshwater lake in China, has deteriorated steadily in recent years and local governments have made efforts to manage the potential eutrophication. In order to investigate the transport and retention processes of dissolved substances, the hydrodynamic model, Environmental Fluid Dynamics Code (EFDC) was applied by using the concept of water age. The simulated results showed agreement with the measured water level, discharge, and inundation area. The water age in Poyang Lake was significantly influenced by the variations of hydrological conditions. The annual analysis revealed that the largest averaged water age was observed during the wet year (2010) with 28.4 days at Hukou, the junction of the Yangtze River and Poyang Lake. In the normal season (April), the youngest age with 9.1 days was found. The spatial distribution of water quality derived from the remote sensing images suggested that a higher chlorophyll-a concentration, lower turbidity, and smaller water age in the eastern area of Poyang Lake might threaten the regional aquatic health. The particle tracking simulation reproduced the trajectories of the dissolved substances, indicating that the water mass with greater nutrient loading would further lead to potential environmental problems in the east lake. Moreover, the water transfer ability would be weakened due to dam (Poyang Project) construction resulting in the rising water levels in periods of regulation. Generally, this study quantified an indicative transport timescale, which could help to better understand the complex hydrodynamic processes and manage wetland ecosystems similar to Poyang Lake.
authors.affiliation: State Key Laboratory of Information Engineering in Surveying, Mapping and Remote Sensing, Wuhan University, Wuhan, 430079, China.
authors.forename: Hengda
authors.initials: H
authors.lastname: Qi
authors.affiliation: State Key Laboratory of Information Engineering in Surveying, Mapping and Remote Sensing, Wuhan University, Wuhan, 430079, China. lujzhong@whu.edu.cn.|INPT/UPS, Ecolab, University of Toulouse, Avenue de l'Agrobiopole, 31326, Castanet Tolosan Cedex, France. lujzhong@whu.edu.cn.
authors.forename: Jianzhong
authors.initials: J
authors.lastname: Lu
authors.affiliation: State Key Laboratory of Information Engineering in Surveying, Mapping and Remote Sensing, Wuhan University, Wuhan, 430079, China.|Key Laboratory of Poyang Lake Wetland and Watershed Research, Ministry of Education, Jiangxi Normal University, Nanchang, 310022, China.
authors.forename: Xiaoling
authors.initials: X
authors.lastname: Chen
authors.affiliation: INPT/UPS, Ecolab, University of Toulouse, Avenue de l'Agrobiopole, 31326, Castanet Tolosan Cedex, France.|CNRS, Avenue de l'Agrobiopole, 31326, Castanet Tolosan Cedex, France.
authors.forename: Sabine
authors.initials: S
authors.lastname: Sauvage
authors.affiliation: INPT/UPS, Ecolab, University of Toulouse, Avenue de l'Agrobiopole, 31326, Castanet Tolosan Cedex, France.|CNRS, Avenue de l'Agrobiopole, 31326, Castanet Tolosan Cedex, France.
authors.forename: José-Miguel
authors.initials: JM
authors.lastname: Sanchez-Pérez
mesh_terms: D002681:China; D004784:Environmental Monitoring; D005068:Eutrophication; D057446:Hydrodynamics; D062070:Hydrology; D060106:Lakes / Q000032:analysis*; D008962:Models, Theoretical; D012621:Seasons; D060753:Water Quality; D053833:Wetlands
keywords: Numerical simulation; Particle tracking; Poyang Lake; Remote sensing; Water age; Water quality