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Chen Y.Y.,Tianjin University | Zhang C.,Tianjin University | Gao X.P.,Tianjin University | Wang L.Y.,Yuqiao Reservoir Administrative Bureau of Luan River Tianjin Water Diversion Project
Water Science and Technology | Year: 2012

To study the spatial and temporal trends of water quality in the Yuqiao Reservoir (Ji County, Tianjin) in China, water quality data for ten physical and chemical parameters from three monitoring stations (S1, S2 and S3) was collected from 1989 to 2007 and from an other three stations (S4, S5 and S6) during the period of 1999-2007. A one-way ANOVA was employed to evaluate the spatial variation of water quality for each station. The results showed that there were statistically significant spatial differences for most water quality parameters except temperature and dissolved oxygen in the entire reservoir, and the concentrations of most parameters were higher in the uppermost part of the reservoir. The temporal trend study was conducted using the Seasonal-Kendall's test. The results revealed improving trends of water quality from 1989 to 2007, including a reduction of total phosphorous, temperature and biochemical oxygen demand and an increase of dissolved oxygen. High N:P ratios, ranging from 52.61 to 78.75, indicated that the reservoir was a phosphorous-limited environment. This study suggests long-term spatial and temporal variations of water quality in the Yuqiao Reservoir, which could be informative for water quality managers and scientists. © IWA Publishing 2012. Source


Zhang C.,Tianjin University | Gao X.,Tianjin University | Wang L.,Yuqiao Reservoir Administrative Bureau of Luan River Tianjin Water Diversion Project | Chen Y.,Tianjin University
Journal of Hydroinformatics | Year: 2013

This study presents the Yuqiao Reservoir Water Quality Model (YRWQM), a three-dimensional hydrodynamic and water quality model of the Yuqiao reservoir, China. The YRWQM was developed under the environmental fluid dynamics code (EFDC) model and was calibrated and verified to hydrodynamic and water quality data, using two sets of observed data from January 1 to December 31, 2006 and from May 1 to October 31, 2007, respectively. The primary hydrodynamic and transport driving forces are inflows/outflows and surface wind stresses. Considering effects of water transfer and wind on the advection-dispersion processes, the model results showed better agreements with observed data in the reservoir. The YRWQM predicted the variations of water quality resulting from agricultural pollution which flowed into the reservoir with floods lasting for 12 days in 2009. The results indicated that the concentrations of chemical oxygen demand and total nitrogen were increased 225 and 314%, respectively. Considering the interactions between chlorophyll-a and nitrogen in the model, the results indicated the reservoir was not a nitrogen-limited environment. We suggest the management should focus on agricultural pollution strategies for the reservoir during the flood period. The YRWQM could be a useful tool for water sources management in the reservoir. © IWA Publishing 2013. Source


Zhang C.,Tianjin University | Gao X.,Tianjin University | Wang L.,Yuqiao Reservoir Administrative Bureau of Luan River Tianjin Water Diversion Project | Chen X.,Yuqiao Reservoir Administrative Bureau of Luan River Tianjin Water Diversion Project
Ecological Engineering | Year: 2014

Light intensity plays an important role in determining the distribution of submerged macrophyte. A modified SAVM (M-SAVM) was constructed to simulate the role of epiphyton and water level for the biomass and distribution of Potamogeton crispus in the Yuqiao Reservoir in China. M-SAVM is developed by modification of the light attenuation equation, which is determined by the water transparency (Secchi depth) and epiphyton. The model was calibrated and verified by biomass using two datasets, from the seedling establishment until dying out, in 2008 and 2009. Five hydraulic scenarios were simulated by M-SAVM to analyze the relationship between biomass and water depth. Results showed that epiphyton increase had a slightly low light intensity limitation coefficient to suppress plant growth in M-SAVM. Significant negative correlation (p< 0.01, r=-0.97) between biomass and water depth existed in the reservoir. The biomass increases under low water levels due to increasing underwater light intensity and decreases when the water level is raised. M-SAVM could be a useful tool for submerged macrophyte management in the reservoir and for maintaining intermediate vegetation biomass by fluctuating water level strategies in shallow lakes. © 2015 Elsevier B.V. Source

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