Time filter

Source Type

Wang H.,Hohai University | Zhou Y.,Hohai University | Tang Y.,Hohai University | Wu M.,Hohai University | Deng Y.,Hydrology Bureau of Jiangxi Province
International Journal of Environmental Research and Public Health | Year: 2015

A new method, with the non-fully mixed coefficient (NFMC) considered, was put forward to calculate the water environmental carrying capacity (WECC) for huge river-connected lakes, of which the hydrological conditions always vary widely during a year. Poyang Lake, the most typical river-connected lake and the largest freshwater lake in China, was selected as the research area. Based on field investigations and numerical simulation, the monthly pollutant degradation coefficients and non-fully mixed coefficients of different lake regions were determined to explore the WECCs of COD, TN and TP of Poyang Lake in a common water year. It was found that under the hydrological conditions of a common water year the total WECCs of COD, TN and TP in the lake were respectively 181.9 × 104 t, 33.3 × 104 t and 1.86 × 104 t. Due to the varied lake water volume and self-purification ability, an evident temporal fluctuation of WECCs in Poyang Lake was observed. The dry seasons were characterized by a higher NFMCs but lower WECCs owing to the lower water level and degradation ability. Variation coefficients of COD and TN WECC were close to each other, of which the average level was about 58.5%, a little higher than that of TP. © 2015 by the authors; licensee MDPI, Basel, Switzerland.

Wang H.,Hohai University | Wu M.,Hohai University | Deng Y.,Hydrology Bureau of Jiangxi Province | Tang C.,Desert Research Institute | Yang R.,Hohai University
International Journal of Environmental Research and Public Health | Year: 2014

In this paper, we propose a coupled method to optimize the surface water quality monitoring sites for a huge freshwater lake based on field investigations, mathematical analysis, and numerical simulation tests. Poyang Lake, the largest freshwater lake in China, was selected as the research area. Based on the field investigated water quality data in the 5 years from 2008 to 2012, the water quality inter-annual variation coefficients at all the present sites and the water quality correlation coefficients between adjacent sites were calculated and analyzed to present an optimization scheme. A 2-D unsteady water quality model was established to get the corresponding water quality data at the optimized monitoring sites, which were needed for the rationality test on the optimized monitoring network. We found that: (1) the water quality of Piaoshan (No. 10) fluctuated most distinguishably and the inter-annual variation coefficient of NH3-N and TP could reach 99.77% and 73.92%, respectively. The four studied indexes were all closely related at Piaoshan (No. 10) and Tangyin (No. 11), and the correlation coefficients of COD and NH3-N could reach 0.91 and 0.94 separately. (2) It was suggested that the present site No. 10 be removed to avoid repeatability, and it was suggested that the three sites of Changling, Huzhong, and Nanjiang be added to improve the representativeness of the monitoring sites. (3) According to the rationality analysis, the 21 optimized water quality monitoring sites could scientifically replace the primary network, and the new monitoring network could better reflect the water quality of the whole lake. © 2014 by the authors; licensee MDPI, Basel, Switzerland.

Gong J.,Jiangxi Normal University | Wu D.-Y.,Jiangxi Normal University | Yu Z.-W.,Hydrology Bureau of Jiangxi Province
International Conference on Challenges in Environmental Science and Computer Engineering, CESCE 2010 | Year: 2010

The water resource in Jiangxi Province is very crucial to ecological security of China.According to the data of recent years, this paper analysize the current status of water resources. It points out that Jiangxi is scarce of water seasonally. With respect to the problem, several countermeasurements including spatial information techniques are put forward, which can effectively solve these problems. However, to fulfill this task need more efforts. © 2010 IEEE.

Wang H.,Hohai University | Zhang Z.,Hohai University | Deng Y.,Hydrology Bureau of Jiangxi Province | Wang S.,Hydrology Bureau of Poyang Lake | He C.,Nanyang Technological University
Environmental Earth Sciences | Year: 2016

In this paper, an improved simulation method was developed to investigate the mechanisms of algal growth in Poyang Lake, which is the largest freshwater lake and the most typical river-connected lake in China. In view of its frequent water and sediment exchange with the external rivers, the influences of flow disturbance and suspended sediment concentration on algal growth were quantitatively analyzed based on field investigation and laboratory experiment, and the controlling equations of l(u) and g(S) were established and embedded into the traditional algal growth model for more accurate simulation in Poyang Lake. The improved model was calibrated and validated against the consecutive field monitoring data from March to November in 2012. By simulation, the algal concentration fluctuation in a common-water year and the spatial distribution under two typical current structures: “Gravity Style” and “Jacking Style,” were quantitatively estimated. The results showed that the improved model gave a good approximation of the algal growth processes under the varied water–sediment environment in Poyang Lake. Algal concentrations in the middle area were evidently higher than that in the south and north lake area, while the variation trends were basically the same. Due to the slower current, the algal concentration under “Jacking Style” flow structure was averagely increased by 18.8 % than that under the “Gravity Style.” © 2015, Springer-Verlag Berlin Heidelberg.

Liu X.,CAS Nanjing Institute of Geography and Limnology | Qian K.-M.,CAS Nanjing Institute of Geography and Limnology | Tan G.-L.,Hydrology Bureau of Jiangxi Province | Xing J.-S.,Hydrology Bureau of Jiangxi Province | And 2 more authors.
Huanjing Kexue/Environmental Science | Year: 2014

As one of the human activities that transform nature, construction of dams and dykes may impose significant effects on lake ecosystems. Due to lacking of comparative data for ecological monitoring, how the changes of phytoplankton community structure respond to altered hydrological connectivity between lakes and other water bodies is still unknown. This work chose Junshan Lake, the typical isolated lake from Poyang Lake floodplain, to investigate the succession in phytoplankton communities responding to altered connectivity. Phytoplankton samples were collected during the wet and dry seasons in Junshan Lake, to analyze the phytoplankton community structure. The results showed that, fifty three genera from six phyta were identified in Junshan Lake, with Chlorophyta (47.2%), Bacillariophyta (22.2%), Cyanophyta (14.8%) and Euglenophyta (9.3%) being the main phyta. The dominant species were Ceratium hirundinella (20.5%), Anabeana spp. (18.5%) and Microcystis spp. (12.9%) during the wet seasons. Cryptomonas ovate (38.4%), Aulacoseira granulata (15.2%) and Microcystis spp. (10.5%) dominated during the whole dry seasons. The total phytoplankton abundance was mainly composed of Cyanophyta (85.4%-87.0%). The total phytoplankton biomass was dominantly made up of Cyanophyta (45.0%), Dinophyta (21.1%), Bacillariophyta (15.6%) and Chlorophyta (11.5%) during the wet seasons. Cryptophyta (38.2%), Bacillariophyta (31.3%) and Cyanophyta (21.1%) were the main contributors of the total phytoplankton biomass during the dry seasons. The phytoplankton community structure changed from Dinophyta-Bacillariophyta type during the wet seasons of 2007-2008 to Cyanophyta-Dinophyta type during the wet seasons of 2012-2013, and changed from Dinophyta-Bacillariophyta type during the dry seasons of 2007-2008 to Cryptophyta-Bacillariophyta-Cyanophyta type during the dry seasons of 2012-2013. The abundance and biomass increased from 2.66×106 cell·L-1 during 2007-2008 to 6.77×107 cell·L-1 during 2012-2013, and from 0.72 mg·L-1 during 2007-2008 to 12.30 mg·L-1 during 2012-2013, respectively. The succession pattern of phytoplankton community in the Junshan Lake showed a decrease in the proportion of oligotrophic species as Chrysophyta and Dinophyta, and an increase in eutrophic species as Cyanophyta and Cryptophyta. Thus, being isolated from Poyang Lake might alter hydrologic factors so that the water exchange time became longer and the water flow became slower which could promote the growth and aggregation of phytoplankton eutrophication indicator species in Junshan Lake.

Discover hidden collaborations