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Jin B.,Hohai University | Xu Z.,Nanjing Water Planning and Designing Institute Company Ltd | Yan X.,Nanjing Water Planning and Designing Institute Company Ltd
International Journal of Multimedia and Ubiquitous Engineering | Year: 2016

Based on the powerful open interface of WeChat enterprise account features, a site investigation system is proposed for management of hydraulic engineering projects. The implemented functions include integrated photographing, GPS based positioning and information submission from handheld mobile devices. By leveraging cloud computing and mobile internet technologies, all the site investigation information is collected by designers on the unified mobile terminal including smart phones, tablets, and laptops. The proposed system provides various services, such as batch uploading, geological position mapping, data query and data downloading of the investigated information of specific hydraulic engineering project. Moreover, high level functions are realized through high-precision location based service, synchronous saving, resource sharing and quick search. Our system outperforms and changes the traditional working mode of site investigation of hydraulic engineering projects, as well as improves the working efficiency and accuracy for data collection in the whole life of the project management. © 2016 SERSC.

Wang J.,Nanjing University of Information Science and Technology | Hiroshi I.,Yamanashi University | Ning S.,Hefei University of Technology | Khujanazarov T.,Kyoto University | And 2 more authors.
Forests | Year: 2016

Located in the southeastern China and northern Vietnam, the Red River is an important international trans-boundary river that has experienced rapid deforestation and environmental changes over the past decades. We conducted attribution analysis of impacts of various environmental changes on streamflow and sediment load. The contribution of reclassified environmental changes to total change of the streamflow and sediment load was separated. Land cover change based on climate-induced and human-induced indicators were defined. We found that human-induced land cover change was the main factor affecting changes of the streamflow and sediment load. Changes of the land cover were more pronounced in the dry season than in the wet season whereas sediment load changed more in the wet season than in the dry season. In addition, changes in sediment load were mainly caused by human-induced land cover change and the changes of land cover were more influential on sediment load than on streamflow in the Red River basin. © 2016 by the authors.

Lin T.,Hohai University | Zhang J.,Nanjing Water Planning and Designing Institute Ltd | Chen W.,Hohai University | Sun Y.,Hohai University
Clean - Soil, Air, Water | Year: 2014

Bench-scale experiments were conducted to evaluate effects of UV radiation (UVR) on Limnoithona sinensis (Copepoda, Crustacea). Results showed that water depth, wavelength, and irradiation time significantly reduced the swimming activity of L. sinensis. The inactivation rate increased with irradiation time, and there was an inverse relation between inactivation rate and water depth. Positive phototaxis was observed in copepods exposed to visible light with wavelengths of 480 or 500nm, which caused a substantial increase in the inactivation rate when UVR was combined with visible light. Scanning electron microscopy showed that the skin of L. sinensis inactivated by UVR appeared dry and wrinkled, which was possibly due to induction of osmotic changes across cell membranes. As indicated by three-dimensional fluorescence spectra showing leakage of protoplasm to the external environment. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Hao S.,Hohai University | Yu F.,Hohai University | Zhang Z.,Hohai University | Jin Y.,Nanjing Water Planning and Designing Institute Company Ltd | Hua J.,Nanjing Water Planning and Designing Institute Company Ltd
Advances in Science and Technology of Water Resources | Year: 2015

By Combining the variation of meteorological factors, it is analyzed the impact of climate change on water requirement of main crops in Nanjing, China and it is presented some measures to address the impacts of climate change. For achieving this goal, water requirement of crops in Nanjing from 1951 to 2005 is calculated with the method of Mann-Kendall. Combining the variation of meteorological factors, the paper analyzes the impact of climate change on water requirement of main crops in Nanjing and put forward some measures to address climate change. The data show that the decrease of water requirement of summer crops, such as rice, cotton and corn, is related with the insignificant increase of summer temperature, increase of rainfall, drop of sunshine hours, and slowdown of wind speed. While the increase of water requirement of winter wheat and canola is mainly related to the highest growth rate of winter and spring temperatures, the effect of drop in sunshine hours and slowdown in wind speed is not enough to offset that of the increase in temperature and the reduction in humidity. The cropping system is affected by temperature, which may bring the increase of total crop water requirement. Thus, water-saving irrigation, especially water impoundment for controlling irrigation is necessary to reduce irrigation and drainage quota, weaken greenhouse effect and reduce the impact of climate change on the rice production. ©, 2015, Editorial Office of Journal of Hohai University (Nature Sciences). All right reserved.

Lu J.,Nanjing Hydraulic Research Institute | Huang T.,Nanjing Water Planning and Designing Institute Ltd. | Niu Z.,Nanjing Hydraulic Research Institute
Earth and Space 2012 - Proceedings of the 13th ASCE Aerospace Division Conference and the 5th NASA/ASCE Workshop on Granular Materials in Space Exploration | Year: 2012

The sluices play an important role in engineering, agriculture and social economic development and also occupy an important position in the river basins or city flood control and drought work. In combination with the characteristics of sluices in plain area, the influence on water discharge through sluice and discharge way of sluices were analyed in this article. An integrated operation control model for Sluice was established. Then the criterions including the water level up and down the sluice, the open orders of sluices and the number of open holes and open height of sluices were determined in the article. Their evaluation indexes are determined by the principle of which degree comes close and judged by experts. Finally the prediction results were came up through the fuzzy comprehensive evaluation and compared with the indexes of the safty degrees and the conclusion of operation control could be made by this method. © ASCE 2012.

Zhang R.,Yangzhou University | Zhang R.,Jiangsu Surveying and Design Institute of Water Resources Co. | Li C.,Nanjing Water Planning and Designing Institute Ltd. | Yao L.,Jiangsu Surveying and Design Institute of Water Resources Co. | Zhu H.,Yangzhou University
Paiguan Jixie Gongcheng Xuebao/Journal of Drainage and Irrigation Machinery Engineering | Year: 2012

In order to obtain the transient hydraulic characteristics of the bulb pump unit in a pump station with VFD during startup, the essential features of low-speed synchronous startup controlled by VFD were analyzed initially. Then the moment equilibrium equation of the rotor of pump unit was established in the startup transient period. The mathematically expressing approach for the electromagnetic torque in the synchronous motor in terms of time was investigated. The resistance moments, inclusive of hydraulic resistance moment, bearing frictional moment and motor cooling fan resistance moment etc, and their mathematical expressions were clarified. Finally, the flow rate allocation and conservation between the rapid-drop gate and flap valve during the transient period were determined. Taking Huaiyin No. 3 Pumping Station as a study case, the startup transient process of the pump unit under the design condition was simulated to obtain the primary electrical and hydraulic parameters. In the simulation, the pump started running when the instant exciting current reached 0.63 times its design value and the frequency was about 6.5 Hz, causing a 15 s lag delay. As a result, a best match was obtained between the motor rotational speed frequency and the lag time for opening the rapid-drop gate. At the design condition, when the rotational speed of the synchronous motor is linearly increased from 0 to 125 r/min in 100 s interval, the optimal lag time is 70 s for opening the rapid-drop gate.

Zhai Y.,Hohai University | Jin Y.,Nanjing Water Planning and Designing Institute Co. | Chen L.,Hohai University
Advance Journal of Food Science and Technology | Year: 2015

A well-designed subsurface drainage system with reasonable drain space and depth contributes to large ratio of desalination and high crop yield. In order to find out the optimal space and depth of subsurface drainage tubes for tomato cultivation in greenhouse salty soils in south of China, drainage treatments with different buried methods were designed, the tomato quality, yield, Irrigation Water Use Efficiency (IWUE) and surface soil electricity conductivity in the treatments were observed during 2010 to 2012 growth seasons and the principle component analysis model and projection pursuit model were used to select the treatment with best comprehensive effects. Results showed that: (1) The tomato yield was increased by 14.21 to 50.29% during the growth seasons; (2) Surface soil EC decreased significantly, although in the process of experiments, surface soil EC of some treatments showed a temporary rise; (3) Under the same buried depth, the closer arrangement of subsurface drainage tubes appeared to be more effective for the yield gaining and topsoil desalination; (4) T7 was proved to be the optimal treatment according to the calculations of projection pursuit model, the comprehensive effects of which were the best, mainly embodying in improving the tomato quality, increasing the yield and IWUE and reducing salinity in topsoil. In this study, 0.8m depth combining with 4m space was selected as the optimized layout of subsurface drainage tubes for the tomato cultivation in greenhouse salty soils of south China. © Maxwell Scientific Organization, 2015.

Luo C.,Yangzhou University | Cheng L.,Yangzhou University | Liu C.,Yangzhou University | Qi W.,Nanjing Water Planning and Designing Institute Co. | Shang Y.,Yangzhou University
Paiguan Jixie Gongcheng Xuebao/Journal of Drainage and Irrigation Machinery Engineering | Year: 2015

To analyse the hydraulic performance of the mixed-flow pump with vaned diffuser in a waterjet propulsion system more accurately, CFX code is used to simulate the steady turbulent flow in the system, which consists of a pump, entry duct, water body below the vessel and nozzle, at various flow rates by means of the standard k-ε turbulence model. The hydraulic loss distribution, hydraulic performance, axial thrust and flow field features are exploited. Because the geometry of entry duct is relatively complex where its rectangular section at the inlet needs to be transformed into a circular one at the outlet, the hydraulic loss takes a maximum proportion in the entry duct, especially at a low flow rate. In that case, the proportion exceeds 90%. However, this proportion reduces with increasing flow rate, and the hydraulic loss proportions in the other components increase accordingly. The system is subject to the hydraulic instability around 0.50Qd. The high efficiency zone exists in the range of 0.76Qd and 1.10Qd. The axial thrust generated by the pump diminishes when the flow rate rises. At a small flow rate, the flow pattern in the impeller is complicated, and the spanwise vortex, radial vortex and leakage vortex are evident. Fortunately, these vortices are shrunk until disappear with increasing flow rate. ©, 2015, Editorial Department of Journal of Drainage and Irrigation Machinery Engineering. All right reserved.

Zuo D.-J.,Tianjin Research Institute for water transport engineering | Zuo D.-J.,Hohai University | Chen L.,Hohai University | Tian Z.-W.,Nanjing Water Planning and Designing Institute Co. | Qi C.-G.,Ningbo University
Yantu Gongcheng Xuebao/Chinese Journal of Geotechnical Engineering | Year: 2015

Based on a liquefied natural gas terminal wharf project in Tianjin, the finite element software ABAQUS is used to study the mechanical characteristics of pile groups of wharf foundation under lateral and vertical cyclic loadings, and the influence of cyclic period of lateral and vertical loadings is discussed. The results indicate that under the lateral and vertical cyclic loadings, the stress of piles redistributes, the shaft force of piles increases, and the side resistance decreases. The increase amplitude of shaft force row piles is the largest. The range of side resistance is mainly concentrated in the area of more than 1/3 of pile length. The cyclic period has great influence on the stress redistribution: with change of the cyclic period, load distribution of piles adjustes gradually, the shaft forces of front and back row piles increase, and the shaft forces and side resistances of the middle row piles decrease. When the cyclic period reaches a certain value, the shaft forces and side resistances of piles no longer change and tend to a steady state. ©, 2015, Yantu Gongcheng Xuebao/Chinese Journal of Geotechnical Engineering. All right reserved.

Gao H.,Hohai University | Zhang F.,Nanjing Water Planning and Designing Institute Co. | Qin Z.,Hohai University
Journal of Hohai University | Year: 2013

Based on the application and development platform provided by the calculation toolbox PETSc, a parallel linear solver was developed for single multi-core computers. Data and operations that are necessary for an FEM analysis were packaged in the form of a class provided by C++, and the linear FEM iteration method was used to solve problems in parallel. Test results show that 3G memory and four nuclear computers can compute a 3D linear FEM with a number of nodes of 800 000. The speedup ratio was up to 1.81 for two processes and 3.24 for four processes. The solver has a good ability to adapt to morbid equations. Iteration can converge for the finite element model with elastic modulus of materials differing by 100 000 times.

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