Hydrology and Water Resources Investigation Bureau of Jiangsu Province

Nanjing, China

Hydrology and Water Resources Investigation Bureau of Jiangsu Province

Nanjing, China
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Lu G.-H.,Hohai University | Ma Q.,Hydrology and Water Resources Investigation Bureau of Jiangsu Province
Water Science and Engineering | Year: 2011

Black water aggregation (BWA) in Taihu Lake is a disaster for the lake environment. It is a phenomenon resulting from water environmental deterioration and eutrophication caused by accumulation of pollutants in the lake, according to research on the water quality, pollutants of BWA, and occurrence mechanisms of BWA. Dead algae are the material base of BWA, the polluted sediment is an important factor for the formation of BWA, and hydrological and meteorological conditions such as sun light, air temperature, wind speed, and water flow are the other factors that may lead to the formation of BWA. Thioether substances such as dimethyl trisulfide are the representative pollutants of BWA. Parameters such as chlorophyll-a, DO, pH, and water temperature are sensitive indicators of BWA. Measures such as algae collection, ecological dredging, pollution control, and water diversion from the Yangtze River to the lake, are effective, and strengthening aeration is an emergency measure to control BWA. © 2011 Editorial Office of Water Science and Engineering.


Liu Z.,Hohai University | Lu G.,Hohai University | He H.,Hohai University | Wu Z.,Hohai University | He J.,Hydrology and Water Resources Investigation Bureau of Jiangsu Province
Water (Switzerland) | Year: 2017

Water vapor transport (WVT) is an important element in drought development. In this study, we examined the geographical and vertical anomalies of WVT during severe summer and early fall drought processes and their occurrence, persistence and recovery phases in Southwest China (SWC) by using the method of standardized anomalies (SA) and composite analysis. The SA-based indices of WVT were built up to quantify composited anomalous WVT channels objectively. Essentially, we further explored the synchronous and lagged correlations between drought processes and these channels. Key points and limitations include: (1) Two drought-related WVT channels were geographically identified with composited SA below -0.2, based on the composite of severe drought processes. The Somali channel is characterized by zonally less-than-normal African-Asian continental WVT anomalies originating from Somalia, whereas the IndoChina-Peninsula channel represents meridionally less-than-normal WVT anomalies from the IndoChina-Peninsula; (2) Both geographical and vertical WVT anomalies were intensified and concentrated at the time of drought occurrence, and then weakened and became scattered at drought recovery; (3) Most drought-related WVT anomalies were distinguishable from those of wetter events; (4) The IndoChina-Peninsula channel performs better in correlations with these drought and wetter processes than the Somali channel. Therefore, dynamic and thermodynamic anomalies need to be investigated, which are important for exploring the drought mechanism. © 2017 by the authors. Licensee MDPI, Basel, Switzerland.


Li Y.-P.,Hohai University | Li Y.-P.,State Key Laboratory of Hydrology Water Resources and Hydraulic Engineering | Qiu L.,Hohai University | Tang C.-Y.,Hohai University | And 4 more authors.
Zhongguo Huanjing Kexue/China Environmental Science | Year: 2014

Uncertainty and sensitivity analysis of four important input conditions on the Environmental Hydrodynamic Fluid Code (EFDC) model results (i.e., water level, water age and currents) was investigated for a large shallow lake, Lake Taihu, China. The four input conditions included three boundary conditions (i.e., inflow/outflow, wind speed, wind direction) and an initial condition (i.e., initial water level). The Latin Hypercube sampling (LHS) as a global sensitivity method was used to estimate the uncertainty and sensitivity from the four input conditions. The results showed that uncertainties in the hydrodynamic process existed due to the uncertainties of model input conditions. Among the four input conditions, the initial water level was the most sensitive factor for the simulated water level and water age with the uncertainty contributions of 85.73% and 66.125% respectively, while it had barely 3% contributions to vertical averaged velocity. Wind speed played a significant role in the uncertainty of the velocity in the surface layer with a sensitivity coefficient of 58.70%, while it only had 5.25% and 3.00% contributions to the simulated water level and water age, respectively. Additionally, there was a similar impact of the four input conditions on the uncertainty of velocities in different layers. The four input conditions' contributions to the velocities were as follows: wind speed (55%~60%) > wind direction (10%~15%) > initial water level ≈ inflow/outflow (1%~5%). Thus, the results provided reliable information for the model prediction of large shallow lakes like Lake Taihu. For different output targets, improving the precision of the input conditions with priority can efficiently enhance the precision of the hydrodynamic model.


Li Y.,Hohai University | Tang C.,Hohai University | Wang C.,Hohai University | Tian W.,Hydrology and Water Resources Investigation Bureau of Jiangsu Province | And 6 more authors.
Ecological Engineering | Year: 2013

To enhance water exchange and alleviate eutrophication in Lake Taihu, the third largest freshwater lake in China, four different inter-basin water diversion named Route One to Four, have been implemented or planned to flush pollutants out of Lake Taihu by transporting freshwater from Yangtze River. Due to the shallowness and large size of Lake Taihu, it is quite complex to set the optimal transferred inflow rate for each route or the combination of routes to maximize the benefits for improving the lake's water exchange with minimum economical cost and environmental impact. In this study, the appropriate transferred inflow rates and environmental impacts of the different water transfer routes on both Lake Taihu ("receiver") and the Yangtze River ("supplier") were assessed using the concept of water age and Lagrangian particle tracking based on a three-dimensional Environmental Fluid Dynamic Code (EFDC) model. The results showed that the appropriate flow rates were quite different from the single route diversion to the combination of routes, depending on priorities such as lowest economical cost and highest water quality improvement for specific lake regions or the entire lake. Two optimal combinations of routes to achieve specific results in different seasons were determined to improve the water exchange of the lake. During the algal bloom seasons, the objective of the combination focused on enhancing water exchange in the specified lake regions such as Meiliang Bay and Zhushan Bay. The optimal flow rates for Route One to Route Four were 80, -70 ("-" means outflow), 100 and 20m3/s, respectively. In the non-algal bloom seasons, the combination concentrated on lowering water ages in the entire lake. The optimal flow rates for Route One to Route Four were 90, -40, 70 and 20m3/s, respectively. The results suggested that the Yangtze River Diversion, as an emergency stopgap measure, played important roles on enhancing water exchange in the lake, but had minimal impact on the Yangtze River. The findings of this study provide useful information for the local government and decision-makers to better understand the physical and hydrological processes of water transfer projects and to assist in managing the water transfer projects. © 2013 Elsevier B.V.


Wan Y.,Nanjing University | Wan Y.,Nanjing University | Ruan X.,Nanjing University | Ruan X.,Nanjing University | And 3 more authors.
Environmental Monitoring and Assessment | Year: 2014

The odour emission characteristics of 22 recreational rivers in Nanjing were investigated and analysed. Eight odorous compounds (ammonia (NH3), hydrogen sulphide (H2S), sulphur dioxide (SO2), carbon disulphide (CS2), nitrobenzene (C6H5NO2), aniline (C6H5NH2), dimethylamine (C2H7N), and formaldehyde (HCHO)) were measured in odour emission samples collected using a custom-made emission flux hood chamber. The results showed that all odorants were detected in all monitoring rivers. NH3 was the main odorant, with emission rates ranging from 4.86 to 15.13 μg/min m2. The total odour emission rate of the Nan River, at 1 427.07 OU/s, was the highest of the all investigated rivers. H2S, NH3 and nitrobenzene were three key odour emission contributors according to their contributions to the total odour emission. A correlation analysis of the pollutants showed there was a significant positive correlation between the emission rate of NH3 and the concentration of ammonia nitrogen (NH4+-N) and total nitrogen (TN). The H2S and SO2 emission rates had a significant positive correlation with sulphides (S2−) and available sulphur (AS) in the water and sediment. The content of TN, NH4+-N, S2− and AS in the water and sediment affected the concentration of H2S, SO2 and NH3 in the emission gases. NH4+-N, S2− and AS are suggested as the key odour control indexes for reducing odours emitted from these recreational rivers. The study provides useful information for effective pollution control, especially for odour emission control for the recreational rivers of the city. It also provides a demonstrate example to show how to monitor and assess a contaminated river when odour emission and its control need to be focused on. © 2014, Springer International Publishing Switzerland.


Wan Y.,Nanjing University | Wan Y.,Nanjing University | Ruan X.,Nanjing University | Ruan X.,Nanjing University | And 3 more authors.
Environmental Monitoring and Assessment | Year: 2014

The odour emission characteristics of 22 recreational rivers in Nanjing were investigated and analysed. Eight odorous compounds (ammonia (NH3), hydrogen sulphide (H2S), sulphur dioxide (SO2), carbon disulphide (CS2), nitrobenzene (C6H5NO2), aniline (C6H5NH2), dimethylamine (C2H7N), and formaldehyde (HCHO)) were measured in odour emission samples collected using a custom-made emission flux hood chamber. The results showed that all odorants were detected in all monitoring rivers. NH3 was the main odorant, with emission rates ranging from 4.86 to 15.13 μg/min m2. The total odour emission rate of the Nan River, at 1 427.07 OU/s, was the highest of the all investigated rivers. H2S, NH3 and nitrobenzene were three key odour emission contributors according to their contributions to the total odour emission. A correlation analysis of the pollutants showed there was a significant positive correlation between the emission rate of NH3 and the concentration of ammonia nitrogen (NH4 +-N) and total nitrogen (TN). The H2S and SO2 emission rates had a significant positive correlation with sulphides (S2-) and available sulphur (AS) in the water and sediment. The content of TN, NH4 +-N, S2- and AS in the water and sediment affected the concentration of H2S, SO2 and NH3 in the emission gases. NH4 +-N, S2- and AS are suggested as the key odour control indexes for reducing odours emitted from these recreational rivers. The study provides useful information for effective pollution control, especially for odour emission control for the recreational rivers of the city. It also provides a demonstrate example to show how to monitor and assess a contaminated river when odour emission and its control need to be focused on. © 2014 Springer International Publishing Switzerland.

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