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A distributed scheme developed for eco-hydrological modeling in the upper Heihe River

Science China Earth Sciences 2015年第1期58卷 36-45页

作者： YANG DaWen GAO Bing JIAO Yang LEI Hui Min ZHANG YanLin YANG HanBo CONG ZhenTao State Key Laboratory of Hydro-science and engineering Department of Hydraulic EngineeringTsinghua University School of water resources and Environment China University of Geosciences Cold and Arid Regions environmental and engineering Research institute Chinese Academy of Sciences

Modeling the hydrological processes at catchment scale requires a flexible distributed scheme to represent the catchment to- pography, river network and vegetation pattern. This study has developed a distributed scheme for eco-hydrological simulation in the upper Heihe River. Based on a 1 km x 1 km grid system, the study catchment is divided into 461 sub-catchments, whose main streams form the streamflow pathway. Furthermore, a 1 km grid is represented by a number of topographically similar ＂hillslope-valley＂ systems, and the hillslope is the basic unit of the eco-hydrological simulation. This model is tested with a simplified hydrological simulation focusing on soil-water dynamics and streamflow routing. Based on a 12-year simulation from 2001 to 2012, it is found that variability in hydrological behavior is closely associated with climatic and landscape condi- tions especially vegetation types. The subsurface and groundwater flows dominate the total river runoff. This implies that the soil freezing and thawing process would significantly influence the runoff generation in the upper Heihe basin. Furthermore, the runoff components and water balance characteristics vary among different vegetation types, showing the importance of coupling the vegetation pattern into catchment hydrological simulation. This paper also discusses the model improvement to be done in future study.

关键词： distributed scheme catchment discretization streamflow pathway hillslope parameterization the upper Heihe River

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Hydrothermal Synthesis and Crystal Structure of a Manganese(II) Coordination Polymer with 1,1′-Biphenyl-2,2′,6,6′-tetracarboxyl Acid and 2,2′:6,2′′-Terpyridine Ligands

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Chinese Journal of Structural Chemistry 2011年第11期30卷 1551-1556页

作者：梅崇珍单雯雯刘秉涛 institute of environmental and Municipal engineering North China University of Water Conservancy and Electric Power

The title compound {[Mn（H2BPTC）（tpy）（H2O）]·（H2O）3}, （1, H4BPTC = 1,1＇- biphenyl-2,2＇,6,6＇-tetracarboxylic acid, tby = 2,2＇：6,2＇-terpyridine） has been synthesized by the hydrothermal reaction, and its structure was determined by X-ray diffraction and characterized by elemental analysis, IR spectrum and thermogravimetric analysis. The crystal is of monoclinic, space group P21/c with a = 10.971（2）, b = 20.776（4）, c = 14.332（3） A, β = 109.25（3）°, MnC31H27N3O12, Mr = 688.50, V= 3084.1（10） A^3, Dc = 1.483 g/cm^3, F（000） = 1420, p = 0.498 mm^-1, S = 1.066 and Z = 4. The final refinement gave R = 0.0447 and wR = 0.1103 for 5107 observed reflections with I 〉 2σ（I）. The title complex has a {[Mn（H2BPTC）（tpy）（H2O）]}, chain structure, and the hydrogen bonding interactions make it more stable. Each chain is further connected to the adjacent ones through π…π, C-H…π and rich hydrogen bonds to form a metal-organic coordination polymer.

关键词： manganese(Ⅱ) 1,1'-biphenyl-2,2',6,6'-tetracarboxyl acid 2,2':6,2'-terpyridine coordination polymer crystal structure

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Applying model simulation and photochemical indicators to evaluate ozone sensitivity in southern Taiwan

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Journal of environmental Sciences 2011年第5期23卷 790-797页

作者： Yen-Ping Peng Kang-Shin Chen Hsin-Kai Wang Chia-Hsiang Lai Ming-Hsun Lin Cheng-Haw Lee Graduate institute of environmental engineering "National" Taiwan University institute of environmental engineering National Sun Yat-Sen University institute of environmental engineering National Sun Yat-Sen University Department of Health Safety and environmental engineering Central Taiwan University of Science and Technology Department of resources engineering National Cheng-Kung University

Ozone sensitivity was investigated using CAMx simulations and photochemical indicator ratios at three sites （Pingtung City, Chao-Chou Town, and Kenting Town） in Pingtung County in southern Taiwan during 2003 and 2004. The CAMx simulations compared fairly well with the hourly concentrations of ozone. Simulation results also showed that Pingtung City was mainly a volatile organic compounds （VOC）-sensitive regime, while Chao-Chou Town was either a VOC-sensitive or a NOx-sensitive regime, depending on the seasons. Measurements of three photochemical indicators （H202, HNO3, and NOy） were conducted, and simulated three transition ranges of H202/HNO3 （0.5-0.8）, O3/HNO3 （10.3-16.2） and O3/NOy （5.7-10.8） were adopted to assess the ozone sensitive regime at the three sites. The results indicated that the three transition ranges yield consistent results with CAMx simulations at most times at Pingtung City. However, both VOC-sensitive and NOx-sensitive regimes were important at the rural site Chao-Chou Town. Kenting Town, a touring site at the southern end of Taiwan, was predominated by a NOx-sensitive regime in four seasons.

关键词： photochemical indicator ozone sensitivity volative organic compounds NOx CAMx

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Nighttime sap flow and its driving forces for Populus euphratica in a desert riparian forest, Northwest China

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Journal of Arid Land 2015年第5期7卷 665-674页

作者： SI Jianhua FENG Qi YU Tengfei ZHAO Chunyan Alxa Desert Eco-hydrology Experimental Research Station Cold and Arid Regions Environmental and Engineering Research InstituteChinese Academy of Sciences Gansu Hydrology and water resources engineering Center

Nighttime sap flow is a potentially important factor that affects whole-plant water balance and water-use efficiency （WUE）. Its functions include predawn disequilibrium between plant and soil water potentials as well as between the increments of oxygen supply and nutrient uptake. However, main factors that drive nighttime sap flow remain unclear, and researches related to the relationship between nighttime sap flow velocity and environmental factors are limited. Accordingly, we investigated the variations in the nighttime sap flow of Populus euphratica in a desert riparian forest of an extremely arid region, Northwest China. Results indicated that P. euphratica sap flow occurred throughout the night during the growing season because of the partial stomata opening. Nighttime sap flow for the P. euphratica forest accounted for 31%-47% of its daily sap flow during the growing season. The high value of nighttime sap flow could be the result of high stomatal conductance and could have significant implications for water budgets. Throughout the whole growing season, nighttime sap flow velocity of P. euphratica was positively correlated with the vapor pressure deficit （VPD）, air temperature and soil water content. We found that VPD and soil water content were the main driving factors for nighttime sap flow of P. euphratica.

关键词： nighttime sap flow stomatal conductance vapor pressure deficit driving factors desert riparian forest

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Experimental study on the effects of artificial bed roughness on turbidity currents over abrupt bed slope change

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International Journal of Sediment Research 2020年第3期35卷 256-268页

作者： Sara Baghalian Masoud Ghodsian Civil and environmental engineering Tarbiat Modares University Civil and environmental engineering and water engineering Research institute Tarbiat Modares University

A series of experimental observations are presented in the current study to discuss the effects of artificial bed roughness on the turbidity current flowing in a rectangular channel with an abrupt change in bed *** this purpose,two different types of elements,sinusoidal and trapezoidal,with various heights and arrangements are considered as artificial bed roughness.A Vectrino velocity meter was used to measure the velocity and sediment concentration *** effects of inlet sediment concentration on front velocity,body velocity,unit discharge,sediment concentration,and suspended load transport rate also were *** equations were developed for estimation of the velocity of a turbidity current over smooth and rough *** unexpected experimental results showed that unlike the effect of roughness height,a change in the roughness arrangement has no significant influence on the velocity of a turbidity ***,the effect of bed roughness on the front velocity of a denser current is more significant.

关键词： Experimental analysis Turbidity current Bed roughness Slope break Velocity profile Concentration profile

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Incipient motion of cohesionless sediments on riverbanks with ground water injection

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International Journal of Sediment Research 2012年第1期27卷 111-119页

作者： Yan LU Yong-jun LU Yee-meng CHIEW Nanjing Hydraulic Research institute State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering School of Civil and environmental engineering Nanyang Technological Univ.

This study investigates the influence of ground water injection on the initial movement of non-cohesive sediment particles on a riverbank slope analytically and *** including the hydraulic gradient in the force analysis,the critical condition was derived to account for the effect of seepage flow, showing that the seepage hydraulic gradient and the riverbank slope are governing parameters in modifying the incipient motion of sediments on a riverbank *** investigations were performed in an open-channel flume for various riverbank slopes and hydraulic gradients of injection, showing that the critical shear stress increases with decreasing riverbank slopes and vise-versa,while injection reduces the critical *** experimental data agree well with the theoretical derived expression of the critical condition in the case of injection.

关键词： Incipient motion Riverbank Injection Sediment Seepage

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Porosity Distribution Characteristics and Geological Analysis of Brine Storage Medium in the Qaidam Basin, Western China

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Chinese Geographical Science 2018年第4期28卷 707-716页

作者： HU Shuya XIAO Changlai LIANG Xiujuan ZHAO Quansheng WANG Guangcai ZHANG Jianwei FENG Juan Key Laboratory of Groundwater resources and Environment of the Ministry of Education Jilin University College of environmental and resources Jilin University Department of environmental Science and engineering Qingdao University School of water resources and Environment China University of Geosciences

Underground brine is an unusual water resource that contains abundant mineral resources. It is distributed widely in the Qaidam Basin, western China, a hyperarid inland basin located in the northern Tibetan Plateau. Pores in the brine storage medium act as storage space and transmission channels of underground brine. Therefore, the porosity of brine storage medium determines its ability to store brine. In this study, Mahai Salt Lake was used as the research area as a modern saline lake located in the north area of the Qaidam Basin. A total of 100 porosity samples were collected from eight sampling points in two profiles of the research area at sampling depths of 1.30–314.78 m. The porosity distribution characteristics and influencing factors in brine storage medium were analysed according to the measured porosity data. Based on analysis of the pore structure characteristics, the brine storage medium contains intercrystalline pores, unlike conventional freshwater storage mediums. Moreover, the primary salt rock is susceptible to dissolution by lighter brine, facilitating the formation of secondary porosity. Due to the formation of secondary pores, a porosity greater than 20% remains even at buried depths greater than 100 m. Based on the geological statistical analysis, due to the geographic location, salt formation time, and depositional environment, the porosity values of Mahai Salt Lake do not exhibit a wider distribution, but also show more extreme values than a nearby salt lake. Based on the porosity characteristics by depth, due to the presence of secondary pores, flooding, stratigraphic static pressure, and other factors, porosity shows fluctuations with increasing depth.

关键词： porosity brine storage medium distribution characteristics geological analysis salt lakes in Qaidam Basin

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Application of subfossil cladocerans(water fleas) in assessing ecological resilience of shallow Yangtze River floodplain lake systems(China)

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Science China Earth Sciences 2018年第9期61卷 1157-1168页

作者： Giri KATTEL Ke ZHANG Xiangdong YANG State Key Laboratory of Lake Science and Environment Nanjing Institute of Geography and LimnologyChinese Academy of Sciences environmental Hydrology and water resources Group Department of Infrastructure EngineeringThe University of Melbourne

Majority of shallow floodplain lake ecosystems of the middle and lower reaches of the Yangtze River(China) have gone through serious eutrophication problems over the recent past. The severe environmental deterioration accompanied by cyanobacterial blooms have become major water resource management challenges in the region. An advanced research method is urgently needed to tackle these challenges. The concept of ecological resilience address pressing questions of non-linear dynamics, threshold effects and regime shifts in shallow floodplain lakes, and help manage the ecosystem effectively. Palaeolimnological techniques are important for assessing long term resilience and associated thresholds effects of shallow lake ecosystems. However, the lack of reliable proxy methods available, the assessment of long term ecological resilience of shallow Yangtze River lake systems has become increasingly difficult. Cladocerans(water fleas) play a central role in lacustrine food webs by responding to external drivers and internal ecosystem processes in lakes. Their subfossils are well preserved and becoming one of potential proxy indicators of lake ecosystems change for a longer time scale. This study explores the potential application of subfossil cladocerans and their ephippia in assessing a long term ecological resilience and help better management strategies of lake ecosystems and water resources of the middle and lower reaches of the Yangtze River in China.

关键词： Subfossil cladoceran Yangtze River lake system Food web Ecological resilience Regime shift Threshold

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Swimming behavior of juvenile silver carp near the separation zone of a channel confluence

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International Journal of Sediment Research 2022年第1期37卷 122-127页

作者： Saiyu Yuan Lei Xu Hongwu Tang Yang Xiao Colin Whittaker State Key Laboratory of Hydrology-water resources and Hydraulic engineering Hohai University Yangtze institute for Conservation and Development Department of Civil and environmental engineering The University of Auckland

Knowledge of locomotion of fish near river confluences is important for prediction of fish distribution in a river *** flow separation zone near the confluence of a river network is a favorite habitat and feeding place for silver carp,which is one of the four major species of Chinese carp and usually provides positive rheotaxis to water *** the current study,a series of laboratory experiments were done to determine the behavioral responses of juvenile silver carp to the hydrodynamic forces near the separation zone of a channel *** locomotion and trajectory of juvenile silver carp were recorded by infrared thermal imaging,while the flow velocity field near the separation zone was measured by a Particle Image Velocimetry (PIV) system.A total of 60 juvenile silver carp were released near the separation zone among which 40 carp swam in the upstream *** them,24 carp swam to the tributary and the remaining 16 swam into the main *** all these 24 carp travelled initially along the boundary of the separation zone near the corner,where flow shear was strongest,and then swam to the *** of avoiding zones of strong vorticity,they chose and followed a trajectory along which the flow vorticity was *** encountering these vortical flows,they increased the tailbeat frequency and decreased the tail-beat amplitude to maintain body *** observations provide important knowledge on locomotion of fish near river confluences and are beneficial for the fish habitat protection.

关键词： Channel confluence Flow separation Juvenile silver carp Fish locomotion

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Numerical simulation of transient turbulent cavitating flows with special emphasis on shock wave dynamics considering the water/vapor compressibility

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Journal of Hydrodynamics 2018年第4期30卷 573-591页

作者：王畅畅黄彪王国玉段忠平季斌 School of Mechanical engineering Beijing Institute of Technology State Key Laboratory of water resources and Hydropower engineering Science Wuhan University

The objective of this paper is to investigate the compressible turbulent cavitating flows with special emphasis on shock wave dynamics, with the water/vapor compressibility taken into account. The simulations are performed by solving the compressible, multiphase unsteady Reynolds-averaged Navier-Stokes equations with Saito cavitation model and SST-SAS turbulence model. The compressibility of both the pure water and vapor is considered by employment of the Tait equation of state for water and ideal gas equation of state for vapor. Results are presented for a 3-D NACA66 hydrofoil fixed at ？= 6？ and ？= 1.25 in partial cavitating flows. Cavity collapse induced shock wave formation and propagation, which is closely related to the compressibility characteristics of cavitating flows, are well predicted. Good performance has been obtained for both the cavity evolution process and cavitation induced pressure signals, especially the cavity collapse induced shock wave emission and its interaction with the attached cavity sheet. The pressure peaks in microseconds accompanying the shock wave are captured. The typical quasi-periodic sheet/cloud cavitation evolution is characterized by the following four stages：（1） the growth of the attached cavity sheet,（2） development of re-entrant flow and attached cavity sheet breakup,（3） attached cavity sheet rolling up and cavity cloud shedding, and（4） cloud cavity collapse, shock wave emission and propagation. The cloud cavity collapse induced shock wave dynamics is supposed to be the major origin of cavitation instabilities.

关键词： Turbulent cavitating flows compressibility re-entrant flow shock wave cavitation instability OpenFOAM

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