Cheng Q.,North China University of Water Conservancy and Electric Power |
Cheng Q.,CAS Chengdu Institute of Biology |
Wang R.,Yellow River Water Resources Protection Institute |
Huang W.,Yellow River Water Resources Protection Institute |
And 2 more authors.
Environmental Science and Pollution Research | Year: 2015
The Yellow River Wetland National Nature Reserve (the Sanmenxia section) is an important area of the Yellow River for two important hydrologic gauging stations: the Sanmenxia reservoir and the Xiaolangdi reservoir. Seven sites along the section were selected: Jiziling, Dinghuwan, Houdi, Canglonghu, Shangcun, Wangguan, and Nancun. After the microwave digestion with aqua regia, concentrations of Cu, Pb, Cd, Cr, Zn, and Mn in the sediments were analyzed by flame atomic absorption spectrometry with air-acetylene flame. The results showed that all the concentrations of Cr detected were from the lithogenic source, and 63 % Mn, 48 % Pb, 41 % Cu, 20 % Cd, and 12 % Zn were from the anthropogenic source. The values of the index of geo-accumulation pointed out that there was moderate contamination of Mn at the Dinghuwan (1.04) and Houdi (1.00) sites (class 2), while the modified degree of contamination denoted that the contamination at the Houdi site (2.02) was moderate, nil to very low at the Nancun and Shangcun sites and low at the other sites, consisting with the tendency of pollution load index. For metal toxicity, the sediment pollution index indicated that the sediments of the Canglonghu site were low polluted, that of the Houdi site is nearly slightly contaminated, and those of others were natural and uncontaminated. It was vital to evaluate the degree of contamination with individual and overall elements and even with the metal toxicity. Cu, Pb, and Mn contaminations were aggravated in the Sanmenxia section, and there maybe was one of the main anthropogenic sources of these metals along the Yellow River. The findings were expected to update the current status of the heavy metal pollution in the Sanmenxia section as well as to create awareness concerning the sound condition of the whole reaches of the Yellow River. © 2015, Springer-Verlag Berlin Heidelberg.
Yu Z.-Z.,Hohai University |
Yu Z.-Z.,Yellow River Water Resources Protection Institute |
Wang L.-L.,Hohai University |
Zhu H.,Hohai University |
And 3 more authors.
Sichuan Daxue Xuebao (Gongcheng Kexue Ban)/Journal of Sichuan University (Engineering Science Edition) | Year: 2012
A well validated three-dimensional hydrodynamic and water temperature model considering water surface wind stress and heat exchange was proposed to simulate the water temperature stratification and water ecological environment problems in Xiangxi Bay, after the impoundment of Three Gorges Reservoir. The numerical results showed that the water temperature stratification occurs in spring and summer in Xiangxi Bay. The "tidal movement" in Xiangxi Mouth and the internal waves generated by "tidal flow" are caused by the peak shaving operation of Three Gorges Reservoir. The water temperature and vertical distribution of velocity vary with time, which are induced by the internal waves. The phenomena of water temperature fluctuations at different depth and the upper and lower flow in the opposite direction are captured successfully. The results revealed that the internal waves have remarkable effect on hydrodynamic and water temperature distribution, and the excitation and utilization of the internal waves are expected to inhibit water temperature stratification and to improve water ecological environment.
Zhang L.,Yellow River Institute of Hydraulic Research |
Wang L.,Hohai University |
Yu Z.,Yellow River Water Resources Protection Institute |
Leng Y.,Yellow River Institute of Hydraulic Research |
And 2 more authors.
Applied Mechanics and Materials | Year: 2012
Internal waves have a significant impact on the hydrodynamic and stratification characteristics in the density stratified lakes and oceans. In order to reveal the features of internal waves, a three-dimensional numerical wave tank in regular terrain based on the computational fluid dynamics (CFD) model was established to simulate the processes of non-linear internal solitary waves propagation and evolution. The concept of a fraction volume of fluid (VOF) was employed to track the interface of the two-layer fluid. Comparisons were made between CFD model and weakly non-linear KdV theory, it was shown that the wave amplitude predictions by the CFD model agreed well with the KdV equation. On the other hand, the convergence flow and divergence flow at the water surface were captured successfully by the simulated spatial and temporal distributions of velocity. Some peculiar hydrodynamic characteristics, e. g. turbulence kinetic energy and its dissipation rate in the numerical wave tank were also identified and examined. Consequently, this paper provides a reliable method for understanding the phenomenon of internal waves in stratified water bodies. © (2012) Trans Tech Publications, Switzerland.
Han N.,Tianjin Agricultural University |
Wang Y.,Tianjin Agricultural University |
Sun S.,Tianjin Agricultural University |
Lou G.,Yellow River Water Resources Protection Institute
ICAE 2011 Proceedings: 2011 International Conference on New Technology of Agricultural Engineering | Year: 2011
From 2005 to 2007 in Tianjin, soil infiltration tests were observed in Coastal moist soil regions. This paper used the least square method to analyze the soil infiltration law. Through the analysis that Horton solution has the clear physical meaning and it is more realistic. Infiltration parameters did not change significantly with the time. The mean value of stable infiltration rate is 1.629mm/min, and its coefficient of variation is 0.38. Stable infiltration rate's value ranges from the range of 0.888-2.720 mm / min. The mean value of initial infiltration rate is 5.094mm/min, and its coefficient of variation is 0.54. Initial infiltration rate's value ranges from the range of 1.944-10.994mm/min. © 2011 IEEE.
Zhang J.,Zhengzhou University |
Zhao Y.,China Institute of Water Resources and Hydropower Research |
Zhang J.,Yellow River Water Resources Protection Institute |
Zuo Q.,Zhengzhou University
Applied Mathematics and Information Sciences | Year: 2012
Evapotranspiration is a central process of the hydrological cycle, and various water saving measures are based on it. However, there is little research work on evapotranspiration in the world. In particular, there is rare hydrological cycle-based research on the impact of channel lining on evapotranspiration in arid and semi-arid regions. This paper applies a hydrological cycle model to examine the effect of channel lining on evapotranspiration in the Yellow River Irrigation District in Ningxia Hui Autonomous Region of China where agriculture consumes over half of the total water consumption in the irrigation district. The results show that channel lining can effectively reduce the diversion and consumption of water from the Yellow River. When lining rate is increased from 30% to 60%, the total water diverted from the Yellow River will be reduced by 7.1%, while water consumption is decreased by 3.2%. A higher channel lining rate reduces infiltration into groundwater and lowers the groundwater level, which results in less ecological water consumption. © 2012 NSP Natural Sciences Publishing Cor.
Zhang J.-J.,Yellow River Water Resources Protection Institute |
Ma X.-M.,Yellow River Water Resources Protection Institute |
Huang J.-H.,Yellow River Water Resources Protection Institute |
Xu X.-L.,Yellow River Water Resources Protection Institute
Shuili Xuebao/Journal of Hydraulic Engineering | Year: 2010
This study established a model of self-purification water requirements for the Yellow River and was applied to the upstream reaches of Huayuankou and the river section at Lijin. The results show that in current situation which the point-source pollution of towns discharged excessive pollutants into the Yellow River and the tributaries were seriously polluted, the self-purification water requirements are very large and current water resources of the Yellow River cannot meet the need. In contrast, if the point source pollution of towns up-to-standard discharged and the water quality in tributaries satisfied the water quality objectives of different water function zones, there is not too much change about self-purification water requirements in the Yellow River in different seasons, and self-purification water requirements in dry season and low temperature period is slightly bigger than in other periods. The average flow of the most dry month in 90% probability can basically meet the self-purification water requirements of the Yellow River except for the seriously polluted reaches, such as the Qingtongxia, Shizuishan, and Tongguan, with the corresponding guarantee rate of average flow in the most dry month between 8.5% and 87%.
Shen H.,Chinese Academy of Sciences |
Cao J.,Chinese Academy of Sciences |
Zhang W.,Chinese Academy of Sciences |
Zeng X.,Chinese Academy of Sciences |
Wang H.,Yellow River Water Resources Protection Institute
PLoS ONE | Year: 2014
Winter soil respiration is a very important component of the annual soil carbon flux in some ecosystems. We hypothesized that, with all other factors being equal, shorter winter SR result in reduced contribution to annual soil C flux. In this study, the contribution of winter soil respiration to annual soil respiration was measured for three sites (grassland: dominated by Artemisia sacrorum, Bothriochloa ischaemum and Themeda japonica; shrubland: dominated by Vitex negundo var. heterophylla; plantation: dominated by Populus tomatosa) in a mountainous area of north China. Diurnal and intra-annual soil CO2 flux patterns were consistent among different sites, with the maximum soil respiration rates at 12:00 or 14:00, and in July or August. The lowest respiration rates were seen in February. Mean soil respiration rates ranged from 0.26 to 0.45 mmol m-2 s-1 in the winter (December to February), and between 2.38 to 3.16 μmol m-2 s-1 during the growing season (May-September). The winter soil carbon flux was 24.6 to 42.8 g C m-2, which contributed 4.8 to 7.1% of the annual soil carbon flux. Based on exponential functions, soil temperature explained 73.8 to 91.8% of the within year variability in soil respiration rates. The Q10 values of SR against ST at 10 cm ranged from 3.60 to 4.90 among different sites. In addition, the equation between soil respiration and soil temperature for the growing season was used to calculate the "modeled" annual soil carbon flux based on the actual measured soil temperature. The "measured" annual value was significantly higher than the "modeled" annual value. Our results suggest that winter soil respiration plays a significant role in annual soil carbon balance, and should not be neglected when soil ecosystems are assessed as either sinks or sources of atmospheric CO2. © 2014 Shen et al.