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Impact of environmental change on runoff in a transitional basin:Tao River Basin from the Tibetan Plateau to the Loess Plateau,China

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Advances in Climate Change Research 2019年第4期10卷 214-224页

作者： SUN Long WANG Yue-Yang ZHANG Jian-Yun YANG Qin-Li BAO Zhen-Xin GUAN Xiao-Xiang GUAN Tie-Sheng CHEN Xin WANG Guo-Qing State Key Laboratory of hydrology-water resources and Hydraulic Engineering Nanjing210029China Institute of hydrology and water resources Hohai UniversityNanjing210098China hydrology Bureau Ministry of Water ResourcesBeijing100053China College of Geographical Sciences Nanjing University of Information Science and TechnologyNanjing210044China Research Center fo r Climate Change Ministry of Water ResourcesNanjing210029China School of resources and Environment University of Electronic Science and Technology of ChinaChengdu611731China

Quantification of the impacts of environmental changes on runoff in the transitional area from the Tibetan Plateau to the Loess Plateau is of critical importance for regional water resources *** and abrupt change points of the hydro-climatic variables in the Tao River Basin were investigated during *** also quantitatively separates the impacts of climate change and human activities on runoff change in the Tao River by using RCC-WBM *** indicate that temperature presented a significant rising trend(0.2℃per decade)while precipitation exhibited an insignificant decreasing trend(3.8 mm per decade)during *** runoff in the Tao River decreased significantly with a magnitude of-13.7 mm per decade and abrupt changes in 1968 and 1986 were *** to the baseline period(1956-1968),runoff in the two anthropogenic disturbed periods of 1969-1986 and 1987-2015 decreased by 27.8 mm and 76.5 mm,respectively,which can be attributed to human activities(accounting for 69%)and climate change(accounting for 31%).Human activities are the principal drivers of runoff reduction in the Tao River ***,the absolute influences on runoff reductions by the both drivers tend to increase,from 7.7 mm in 1969-1986 to 24.4 mm in 1987-2015 by climate change and from 20.2 mm to 52.2 mm by human activities.

关键词： Climate change Human activity Runoff change RCCC-WBM model Runoff naturalization Attribution analysis Tao River Basin

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Field experiments on greenhouse gas emissions and nitrogen and phosphorus losses from rice paddy with efficient irrigation and drainage management

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Science China(Technological Sciences) 2011年第6期54卷 1581-1587页

作者： PENG ShiZhang1,2,YANG ShiHong1,2,XU JunZeng1,2 & GAO HuanZhi1,2 1State Key Laboratory of hydrology-water resources and Hydraulic Engineering,Hohai University,Nanjing 210098,China 2College of water Conservancy and Hydropower Engineering,Hohai University,Nanjing 210098,China State Key Laboratory of hydrology-water resources and Hydraulic Engineering Hohai University College of water Conservancy and Hydropower Engineering Hohai University

Greenhouse gas emissions,nitrogen and phosphorous losses through ammonia volatilization,leaching and surface drainage from rice paddy under efficient irrigation and drainage were analyzed based on field experimental data in order to reveal the eco-environmental impacts of efficient irrigation and drainage on rice *** results showed that total methane emission from rice paddy under the controlled irrigation was reduced by more than 80% and total nitrous oxide emission increased by 15.9% compared with flooding *** comprehensive global warming potentials(GWP) of methane and nitrous oxide were 62.23 gCO2 m-2 for rice paddy under the controlled irrigation,reduced by 68.0% compared with flooding *** to large reduction in seepage and surface drainages,nitrogen and phosphorous losses through leaching were reduced by 40.1% and 54.8%,nitrogen and phosphorous losses through surface drainage were reduced by 53.9% and 51.6% from rice paddy under efficient irrigation and drainage compared with traditional irrigation and *** loss through ammonia volatilization was reduced by 14.0%.Efficient irrigation and drainage management is helpful to mitigate greenhouse gases emission,nitrogen and phosphorus losses and their pollution on groundwater and surface water.

关键词： efficient irrigation and drainage nitrogen and phosphorus greenhouse gas ammonia volatilization paddy field

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Transferability and Scalability of Soil Total Carbon Prediction Models in Florida, USA

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Pedosphere 2018年第6期28卷 856-872页

作者： Sabine GRUNWALD Congrong YU Xiong XIONG Department of Soil and water Sciences University of Florida State Key Laboratory of hydrology-water resources and Hydraulic Engineering Hohai University College of hydrology and water Resource Hohai University Agricultural and Biological Engineering Department University of Florida

The applicability, transferability, and scalability of visible/near-infrared(VNIR)-derived soil total carbon(TC) models are still poorly understood. The objectives of this study were to: i) compare models of three multivariate statistical methods, partial least squares regression(PLSR), support vector machine(SVM), and random forest methods, to predict soil logarithm-transformed TC(logTC) using five fields(local scale) and a pooled(regional-scale) VNIR spectral dataset(a total of 560 TC spectral datasets), ii)assess the model transferability among fields, and iii) evaluate their up-and downscaling behaviors in Florida, USA. The transferability and up-and downscaling of the models were limited by the following factors: i) the spectral data domain, ii) soil attribute domain,iii) methods that describe the internal model structure of VNIR-TC relationships, and iv) environmental domain space of attributes that control soil carbon dynamics. All soil logTC models showed excellent performance based on all three methods with R^2> 0.86,bias 2.70%, and ratio of prediction error to interquartile range(RPIQ) > 4.54. The PLSR method performed substantially better than the SVM method to scale and transfer the TC models. This could be attributed to the tendency of SVM to overfit models, while the asset of the PLSR method was its robustness when the models were validated with independent datasets, transferred, and/or scaled. The upscaled soil TC models performed somewhat better in terms of model fit(R2), RPD, and RPIQ, whereas the downscaled models showed less bias and smaller RMSE based on PLSR. We found no universal trend indicating which of the four limiting factors mentioned above had the most impact that constrained the transferability and scalability of the models. Given that several factors can impinge on the empirically derived soil spectral prediction models, as demonstrated by this study,

关键词： attribute domain multivariate statistical methods partial least squares regression random forest support vector machine soil carbon dynamics visible-near infrared spectroscopy

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Effects of Silicon Formulations on Cold Tolerance of Rice Seedlings

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Journal of Northeast Agricultural University(English Edition) 2024年第2期31卷 43-52页

作者： Ren Hongyu Wang Wenbo Li Xuecong Li Shuai Wen Yahuan Zhang Xingwen College of resources and environmental Sciences Northeast Agricultural UniversityHarbin 150030China College of Chemistry and Chemical Engineering Harbin Institute of TechnologyHarbin 150001China

To investigate the effects of silicon formulations on the cold tolerance of rice seedlings,Song Japonica 16(not cold tolerant)and Dongnong 427(cold tolerant)rice varieties were used as test materials and four different types of silicon formulations,Si-50-G,Si-60-G,Si-T-G,and Si-E-G,were applied as foliar sprays at the seedling stage,and a control group CK(equal amount of distilled water)was set *** week after the first silicon spray,two types of rice were subjected to low-temperature stress treatments at day/night temperatures of 12℃/10℃for 2,4,6,and 8 *** effects of different silicon formulations on the chlorophyll,proline(Pro)and soluble sugar contents as well as superoxide dismutase(SOD),peroxidase(POD)and catalase(CAT)activities of rice seedlings under low-temperature stress were compared to find out the effects of silicon formulations on the cold tolerance of rice *** results showed that silicon formulations could significantly increase the chlorophyll content of rice seedling leaves,with Si-50-G being the most effective,with a significant increment of 40.17%compared to the CK at 2 days of low *** silicon formulations significantly increased the proline content and soluble sugar content of rice leaves at low temperature for 4-8 *** Song Japonica 16,the most significant increment in leaf POD activity was observed in Si-E-G treatment at 2,4 and 8 days of temperature stress,with 73.58%,20.95%and 217.24%increases compared to the CK,*** 4 and 6 days of temperature stress,the most significant increase in CAT activity was observed in Si-E-G treatment,with 25.70%and 75.78%increases compared to the CK,*** Dongnong 427,the Si-60-G treatment showed the highest increase in leaf SOD activity for 4 and 8 days of temperature stress,with significant increases of 58.15%and 82.76%compared to the CK,respectively,and the Si-E-G treatment showed the highest increase in leaf POD activity for 2 and 8 days of temperature st

关键词： silicon formulation rice seedling stage cold tolerance physiological indicator

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Initial Dilution of A Vertical Round Non-Buoyant Jet in Wavy Cross-Flow Environment

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China Ocean Engineering 2015年第6期29卷 847-858页

作者：王娅娜陈永平徐振山潘毅张长宽李志伟 State Key Laboratory of hydrology-water resources and Hydraulic Engineering Hohai University College of Harbor Coastal and Offshore Engineering Hohai University Department of Civil and environmental Engineering The Hong Kong Polytechnic University

The phenomenon of wastewater discharged into coastal waters can be simplified as a turbulent jet under the effect of waves and currents. Previous studies have been carried out to investigate the jet behaviors under the current only or the wave only environment. To obtain better understanding of the jet behaviors in a realistic situation, a series of physical experiments on the initial dilution of a vertical round jet in the wavy cross-flow environment are conducted. The diluted processes of the jet are recorded by a high-resolution camcorder and the concentration fields of the jet are measured with a peristaltic suction pumping system. When the jet is discharged into the wavy cross-flow environment, a distinctive phenomenon, namely ＂effluent clouds＂, is observed. According to the quantitative measurements, the jet width in the wavy cross-flow environment increases more significantly than that does in the cross-flow only environment, indicating that the waves impose a positive effect on the enhancement of jet initial dilution. In order to generalize the experimental findings, a comprehensive velocity scale ua and a characteristic length scale l are introduced. Through dimensional analysis, it is found that the dimensionless centerline concentration trajectories cy/l is in proportion to 1/3 power of the dimensionless downstream distance x/l, and the dimensionless centerline dilution 2c aS Q/（u l） is proportional to the square of the dimensionless centerline trajectory cy/l. Several empirical equations are then derived by using the Froude number of cross-flow Frc as a reference coefficient. This paper provides a better understanding and new estimations of the jet initial dilution under the combined effect of waves and cross-flow current.

关键词： turbulent jet initial dilution wavy cross-flow environment experimental study dimensional analysis

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Modelling of a non-buoyant vertical jet in waves and currents

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Journal of Hydrodynamics 2016年第5期28卷 778-793页

作者：徐振山陈永平陶建峰潘毅张长宽李志伟 State Key Laboratory of hydrology-water resources and Hydraulic Engineering Hohai University College of Harbor Coastal and Offshore EngineeringHohai University Department of Civil and environmental Engineering The Hong Kong Polytechnic University

A generic numerical model using the large eddy simulation （LES） technique is developed to simulate a non-buoyant vertical jet in wave and/or current environments. The experimental data obtained in five different cases, i.e., one case of the jet in a wave only environment, two cases of the jet in a cross-flow only environment and two cases of the jet in a wave and cross-flow coexisting environment, are used to validate the model. The grid sensitivity tests are conducted based on four different grid systems and the results illustrate that the non-uniform grid system C （205x99x126 nodes with the minimum size of 1/10 jet diameter） is sufficiently fine for the modelling. The comparative study shows that the wave-current non-linear interaction should be taken into account at the inflow boundary while modelling the jet in wave and cross-flow coexisting environments. All numerical results agree well with the experimental data, showing that：（1） the jet under the influence of the wave action has a faster centerline velocity decay and a higher turbulence level than that in the stagnant ambience, meanwhile the ＂twin peaks＂ phenomenon exists on the cross-sectional velocity profiles, （2） the jet under a cross-flow scenario is deflected along the cross-flow with the node in the downstream, （3） the jet in wave and cross-flow coexisting environments has a flow structure of＂effluent clouds＂, which enhances the mixing of the jet with surrounding waters.

关键词： large eddy simulation (LES) turbulent jet wave cross-flow wave and cross-flow coexisting

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Hybrid method of limit equilibrium and finite element internal force for analysis of arch dam stability against sliding

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Science China(Technological Sciences) 2011年第4期54卷 793-798页

作者： BAO TengFei1,2,3,XU BaoSong1,2,3 & ZHENG XueQing1,2,3 1State Key Laboratory of hydrology-water resources and Hydraulic Engineering,Hohai University,Nanjing 210098,China 2National Engineering Research Center of water resources Efficient Utilization and Engineering Safety,Nanjing 210098,China 3College of water Conservancy and Hydropower Engineering,Hohai University,Nanjing 210098,China State Key Laboratory of hydrology-water resources and Hydraulic Engineering Hohai University National Engineering Research Center of water resources Efficient Utilization and Engineering Safety College of water Conservancy and Hydropower Engineering H

A hybrid method of limit equilibrium and finite element internal force for analysis of arch dam stability against sliding is *** finite element internal force method(FEIFM) is used to provide more accurate thrust forces acting on the faces of a slip body,and the limit equilibrium method(LEM) is employed to evaluate the factor of safety of the slip *** method presented can deal with a slip body with large amount of geometrically complex slip *** addition,compared with the traditional LEM,it can meet the balance condition of the forces in the slip *** example shows that the factor of safety obtained by the method presented agrees well with the theoretical solution.A practical example is also presented to demonstrate the application of the method in the stability analysis of an arch dam *** results from the examples show that the method is promising in analysis of arch dam stability against sliding.

关键词： arch dam stability against sliding limit equilibrium method finite element internal force method

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Biodegradation of Complex Bacteria on Phenolic Derivatives in River water

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Biomedical and environmental Sciences 2009年第2期22卷 112-117页

作者： GUANG-HUA LU CHAO WANG AND ZHE SUN Key Laboratory for hydrology-water resources and Hydraulic Engineering Key Laboratory for Integrated Regulation and Resources Development on Shallow Lakes Ministry of Education College of Environmental Science and Engineering Hohai University Nanjing 210098 Jiangsu China

Objective To isolate, incubate, and identify 4-chlorophenol-degrading complex bacteria, determine the tolerance of these bacteria to phenolic derivatives and study their synergetic metabolism as well as the aboriginal microbes and co-metabolic degradation of mixed chlorophenols in river water. Methods Microbial community of complex bacteria was identified by plate culture observation techniques and Gram stain method. Bacterial growth inhibition test was used to determine the tolerance of complex bacteria to toxicants. Biodegradability of phenolic derivatives was determined by adding 4-chlorophenol-degrading bacteria in river water. Results The complex bacteria were identified as Mycopiana, Alcaligenes, Pseudomonas, and Flavobacterium. The domesticated complex bacteria were more tolerant to phenolic derivatives than the aboriginal bacteria from Qinhuai River. The biodegradability of chlorophenols, dihydroxybenzenes and nitrophenols under various aquatic conditions was determined and compared. The complex bacteria exhibited a higher metabolic efficiency on chemicals than the aboriginal microbes, and the final removal rate of phenolic derivatives was increased at least by 55% when the complex bacteria were added into river water. The metabolic relationship between dominant mixed bacteria and river bacteria was studied. Conclusion The complex bacteria domesticated by 4-chlorophenol can grow and be metabolized to take other chlorophenols, dihydroxybenzenes and nitrophenols as the sole carbon and energy source. There is a synergetic metabolism of most compounds between the aboriginal microbes in river water and the domesticated complex bacteria, 4- chlorophenol-degrading bacteria can co-metabolize various chlorophenols in fiver water.

关键词： Complex bacteria Substituted phenols Biodegradability Synergetic metabolism

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water requirement pattern for tobacco and its response to water deficit in Guizhou Province

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water Science and Engineering 2015年第2期8卷 96-101页

作者： Shi-zhang Peng Xiao-li Gao Shi-hong Yang Jing Yang He-xi Zhang State Key Laboratory of hydrology-water resources and Hydraulic Engineering Hohai University Guizhou Academy of Hydraulic Sciences

The water requirement pattern for tobacco（Yun 85） was identified based on analysis of data obtained from pot experiments in a canopy at the Xiuwen Irrigation Test Central Station in Guizhou Province, China. The results showed that the tobacco water requirement and the tobacco water requirement intensity throughout the growth period in pot experiments were significantly lower than those in field production. In pot experiments, the tobacco water requirement throughout the growth period ranged from 159.00 to 278.90 mm, with a reduction in the range of241e441 mm, as compared with that in field production. Also, the average water requirement intensity at the vigorous growing stage was1.97 mm/d, and the water requirement and water requirement module were 33.80e72.60 mm and 16.39%e33.09%, respectively, at the group stage, almost equal to their values at the vigorous growing stage. The patterns of the tobacco water requirement and water requirement module in pot experiments were different from those in field production. In pot experiments, the tobacco water requirement and water requirement module ranked the highest at the mature stage, followed by those at the group/vigorous growing and rejuvenation stages, while the water requirement intensity ranked the highest at the vigorous growing stage, followed by those at the mature, group, and rejuvenation stages. The pattern of the water requirement intensity in pot experiments was consistent with that in field production. In addition, the response of the tobacco water requirement to water deficit was also analyzed. Serious water deficit at the vigorous growing stage and continuous water stress at the group,vigorous growing, and mature stages can greatly influence the tobacco water requirement. water deficit led to reductions in the water requirement and water requirement intensity at each growth stage. The vigorous growing stage exhibited the highest sensitivity to water *** lower limit of moderate soil water stress at

关键词： water requirement Protected cultivation water deficit Tobacco Guizhou Province

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Analysis and application of the scale effect of flood discharge atomization model

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Science China(Technological Sciences) 2011年第S1期54卷 64-71页

作者： WU ShiQiang 1,WU XiuFeng 1,2,ZHOU Hui 1,CHEN HuiLing 1,SHA HaiFei 1 & ZHOU Jie 1 1 State Key Laboratory of hydrology-water resources and Hydraulic Engineering,Nanjing Hydraulic Research Institute,Nanjing 210029,China 2 Hohai University,Nanjing 210098,China State Key Laboratory of hydrology-water resources and Hydraulic Engineering Nanjing Hydraulic Research Institute Hohai University

The phenomenon of discharge atomization occurs as hydraulic structures discharging,which influences the safety of power station,electrical equipment and produces environmental pollution.A series of physical model tests and feedback analysis are adapted to preliminarily study the scale effect of discharge atomization model by use of the field observation data of discharge *** effect of Re and We numbers of flow on the atomization intensity is analyzed.A conversion relationship of atomization intensity between prototype and model results and the similarity criteria of the atomization range are developed. The conclusion is that the surface tension of discharge atomization model could be ignored when the Weber number is larger than *** case studies are given by use of the similitude criteria of the atomization model.

关键词： discharge atomization scale effect energy dissipation model test feedback analysis

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