• 全国中文核心期刊
  • 中国科技核心期刊
  • 美国工程索引(EI)收录期刊

2015 Vol. 26, No. 2

Display Method:
Prediction of future runoff change based on Budyko hypothesis in Yangtze River basin
GUO Shenglian, GUO Jiali, HOU Yukun, XIONG Lihua, HONG Xingjun
2015, 26(2): 151-160. doi: 10.14042/j.cnki.32.1309.2015.02.001
Abstract:
The calculation formula of annual runoff change was derived based on Budyko hypothesis. The spatial distribution laws of annual mean potential evapotranspiration, precipitation, and aridity index as well as sensitivity coefficient over Yangtze River basin were analyzed. The outputs of global climate model BCC-CSM1-1under RCP4.5 emission scenario was combined with LS-SVM statistical downscaling method to predict future temperature, precipitation and runoff changes in Yangtze River sub-basins. The observed hydrological data series of Wujiang and Hanjiang sub-basins were used to verify Budyko formula for estimating relative runoff change. The results show that precipitation is a dominant factor affecting runoff change; the relative runoff change values are different in each sub-basin and the largest change value is around 10%; The relative runoff changes increase in the north bank and decrease in the south bank of Yangtze River basin during three future periods, i.e., 2020s (2010—2039),2050s (2040—2069) and 2080s(2070—2099). The proposed methodology provides a new approach for runoff prediction in large scale basin and un-gauged region.
Nearest neighbor method based on a coupled similarity indicator and its application in annual runoff prediction
LI Hongxia, HE Qingyan, PENG Hui, QIN Guanghua, DING Jing
2015, 26(2): 161-168. doi: 10.14042/j.cnki.32.1309.2015.02.002
Abstract:
The nearest neighbor method (NNM) based on hydrological similarity is a data-driven prediction method, the use of which allows for avoiding making certain assumptions about the dependence and probability distribution forms of objects of study. One of the key factors that affect the quality of the predicted results using this method is the selection of the measure of the similarity in eigenvectors. In order to give consideration to the information about "direction" and "quantity" while measuring similarity, this paper tries to couple Cosine distance and Euclidean distance to the technical indicator for similarity after thoroughly analyzing their differences and similarities. The nearest neighbor method based on coupled similarity indictor was used for the annual runoff prediction of Yichang hydrological station and Tangnaihai hydrological station, and the annual runoff data for different hydrological characteristics were used for checking. The results show that the nearest neighbor method based on the coupled indicator can appropriately predict annual runoff. It is an effective, feasible method.
Research of the soil erosion on the low-volume unpaved road in the Three Gorge Reservoir area
LIU Yaojun, WANG Tianwei, CAI Chongfa, LI Zhaoxia, LI Heng
2015, 26(2): 169-177. doi: 10.14042/j.cnki.32.1309.2015.02.003
Abstract:
The road network plays a great role in altering the erosion processes and water quality. In this paper, two rural roads with different traffic load, which located in the Jieya watershed Three Gorge Reservoir area, were selected to discuss the road soil erosion and non-point source pollutants loss under the nature rainfall events. The results show that both the runoff rate and erosion rate were higher on the high traffic load roads than that on the low traffic load roads. The rainfall precipitation significantly affected the runoff generation and sediment yield, and the rainfall intensity and rain energy also played great role in affecting the sediment production. The rainfall type had a significant impact on the non-point source pollutants loss, the pollutants loss processes were almost simultaneous to the rainfall under pre-centralized rainfall event, and the first flush effect on the Total Nitrogen, NH4-N, particulate phosphorus, and dissolved phosphorus were much stranger than that under the mid-centralized rainfall event. Slightly first flush effect happened on sediment and the appearance of pick concentration of the pollutants lost was much prior to the pick rainfall intensity when under mid-centralized rainfall event. The nitrogen was lost in the form of Total Nitrogen, which contained of 80% of the total quantity, most of the phosphorus was lost in the form of particulate phosphorus.
Field experiment investigation into the spatial variability of overland flow velocity and soil erosion
TIAN Pei, PAN Chengzhong, XU Xinyi, YANG Fan, LI Changjia
2015, 26(2): 178-186. doi: 10.14042/j.cnki.32.1309.2015.02.004
Abstract:
The spatial variability of overland flow velocity and soil erosion, and their relationship under different discharges, were investigated using a field runoff plot combined with the erosion pins. There exists a positive correlation between flow velocity and the distance from the top of slope, with the correlation becoming more significant as discharge increased. Variability of velocity at each cross section was stronger than that of the lateral section. The eroded sediment yield at the top or bottom of slope was greater than those at the middle. Sediment deposition clearly occurred for small flow discharge, and for high flows net erosion dominated the section of 0—2 m from the top of the slope. As flow discharge increased, the deposition zone gradually shifted down, and the proportion of rill erosion to the total amount of erosion increased. When overland flow velocity was greater than 0.30 m/s, the amount of rill erosion exceeded that of inter-rill erosion, and the erosion amount of the whole slope increased rapidly. As flow discharge increased, the overland flow velocity and erosion amount also increased. However, under the same slope, greater overland flow velocity corresponding to the down-slope tended to generate smaller erosion sediment yield, which may be attributed to the deposition of coarse sediment and the almost saturated sediment carrying capacity at the down-slope.
Effects of the distribution of vegetation on small catchment runoff during rainstorm events
LI Yanmin, AN Yi, LIU Qingquan
2015, 26(2): 187-195. doi: 10.14042/j.cnki.32.1309.2015.02.005
Abstract:
The distribution of vegetation in small catchments is an essential factor determining the generation of runoff during rainstorm events. Using a novel two-dimensional dynamic runoff model, we studied the influence of the distribution of vegetation on rainstorm runoff. First, a kinematic hydrological model of rainstorm events in small watersheds was developed based on a two-dimensional overland flow model. It included canopy interception, surface infiltration, overland flow, and gully flow processes. Data from three rainstorm events in the Heicaohe catchment were then used to verify the model, and good agreement was found. Last, the model was used to examine how the distribution of vegetation and the canopy density affected the runoff process. Model results showed that: First, the vegetation significantly reduces flood discharge and postpones the flood peak, depending on the location and crown density of the vegetation. Second, the efficiency of runoff reduction is substantially higher in downstream and steeply sloped areas (vs. upstream and gently sloping areas), and the degree of crown closure enhances this effect. In fact, in this study, the efficiency of runoff reduction was three times higher in downstream compared with upstream areas, and 30% crown closure resulted in 1.4 times higher efficiency than 20% closure and three times higher than 10% closure.
Study of the cloud structure over the Mount Nyainqêntanglha during summer
ZHANG Xiao, DUAN Keqin, LIU Huancai
2015, 26(2): 196-200. doi: 10.14042/j.cnki.32.1309.2015.02.006
Abstract:
Dynamic behavior of clouds has important implications on weather process and hydrological cycle over the Tibetan Plateau. CloudSat data were used to analyzed cloud types and their water content distribution during summer 2006—2010, in Nyainqêntanglha Mount range. It was observed that cloud water content was affected by vertical distribution of cloud, cloud types. And the difference of the cloud types between the mountain glacier and the mountain non-glacierized was about the precipitation clouds, the precipitation clouds were mainly dominated by the deep convective clouds when the ground was covered over with glacier, and the precipitation clouds were dominated by the nimbostratus when the ground had no glacier. Averaged cloud water content on the southern slope over the glacier and non-glacier were 0.14 g/m3 and 0.18 g/m3, respectively, which indicated that the water vapor was easier to form precipitation when the water vapor approached the glacier, and the glacier had negative impact on the water vapor transport.
Simulation of channel-storage increment process in ice flood period
ZHANG Fangxiu, XI Guangyong, ZHANG Xiaoli, WANG Guoqing, HUANG Rui
2015, 26(2): 201-211. doi: 10.14042/j.cnki.32.1309.2015.02.007
Abstract:
The channel-storage increment was normally divided into three parts including backwater increment, ice increment in the channel and on the beach, detention water by ice cover and ice jam based on observations. In order to investigate the major sources of channel-storage increment during ice flood season, a river ice dynamics model was established to simulate channel-storage increment process (e.g. growth and decay processes of river ice). The model was then applied to the river channel from the Sanhuhekou station to the Toudaoguai station located in the Inner Mongolia. Results show that flood detention under beach ice cover is the principle source of channel storage increment, accounting for about 63.44% of the maximum channel storage increment. The channel stem storage increment and river ice share the rest increment, accounting for approximately 26.56%, 10% of total increment.
1-D movable bed numerical forecast model of salinity of the Qiantang River estuarine reach and its application
SHI Yingbiao, LI Ruohua, YAO Kaihua
2015, 26(2): 212-220. doi: 10.14042/j.cnki.32.1309.2015.02.008
Abstract:
The Qiantang River estuary is an alluvial estuary with strong tidal bore, high sediment concentration and easy changeable riverbed. The interaction between tide and fluvial feedback has great effects on saltwater intrusion. In this paper, a 1-D numerical forecast model of salinity has been developed in the light of riverbed deformation, and the process of water flow, sediment transport, river bed deformation and salinity are fully coupled solved. The governing equations of the model are solved by an explicit finite-volume method with good conservation performance. The verification results show that the riverbed deformation has great influence on chlorine, and the chlorine computed by the movable-bed numerical model agrees well with the measured. Therefore, it is necessary to adopt the movable-bed numerical model in long-duration salinity forecast. Finally, the model is used to investigate the response pattern of saltwater intrusion in the Qiantang River estuary to human activities, such as construction of Xin'anjiang-reservoir and the Qiantang River estuary narrowing regulation. And the problem of the water supply guarantee rate of Hangzhou city is also discussed. The results show that Xin'anjiang-reservoir and the Qiantang River estuary regulation engineering have a significant effect on improving the estuarine freshwater resources and ensuring the safety of water supply of Hangzhou city. In order to raise the water supply guarantee rate to 95%, the measures of scheduling release water discharge from the upstream reservoir and building a new backup reservoir should be taken.
Time scale for effects of sediment on water salinization of estuary reservoirs
GAO Zengwen, LI Yuhao, ZHAO Quansheng, XIE Lei, YE Siyuan
2015, 26(2): 221-226. doi: 10.14042/j.cnki.32.1309.2015.02.009
Abstract:
To predict the time scale for the effects of salt release from sediments on estuary reservoir water, a transient diffusional model was developed to describe the profile of salts in the pore water of sediments. The upper boundary condition and the salt diffusion coefficient of this model were optimized to decrease the uncertainty of the simulation results. A comparison of the transient and steady state release of salts from sediments shows that transient release agrees well with the actual process. The result of a transient simulation for salt release illustrates that it takes more than 600 years for saline sediments to affect the fresh overlying water in the Muguandao Estuary Reservoir. This duration is significantly longer than the life span of a reservoir. The result suggests that instead of measures being taken only at the early stage of an estuary reservoir, effective measures such as periodic monitoring of benthic water and discharging of benthic brackish water should be implemented to prevent salinization throughout its life cycle.
Sharp decline and sluggish rise of shallow groundwater level in the Central Hebei piedmont agricultural region
ZHANG Guanghui, TIAN Yanliang, WANG Dianlong, YAN Mingjiang, WANG Jinzhe
2015, 26(2): 227-232. doi: 10.14042/j.cnki.32.1309.2015.02.010
Abstract:
In response to the constant decline of shallow groundwater level in the Central Hebei piedmont agricultural region, this paper monitored the hour-scale dynamic variation data of water levels and analyzed the difference of groundwater level changes during irrigation and non-irrigation periods by employing time-series variation feature and trend analysis method. Results indicate that the shallow groundwater level declines by more than 1.0 cm/d during irrigation period and rises by less than 1.0 cm/d during non-irrigation period, which is closely correlated with precipitation amount and distribution as well as agricultural exploitation intensity. For irrigation periods with low precipitation, the declining lines and rising lines are below the local average annual water level variation line, while for irrigation periods with abundant precipitation, they are above the local average annual water level variation line. Large-scale intense agricultural exploitation has led to the water level decline by the scale of cm/d, while the water level rise with the scale of mm/d is attributed to the local thick unsaturated zone(thicker than 15m).
Determination of the hydrogeological parameters of a tilted confined aquifer by slug tests
DAI Yunfeng, ZHOU Zhifang, ZHAO Yanrong, WU Rong
2015, 26(2): 233-242. doi: 10.14042/j.cnki.32.1309.2015.02.011
Abstract:
The effect of the dip of an aquifer on the hydrogeological parameters of a tilted confined aquifer was evaluated by slug tests. Using the Kipp model, an analytical solution model was derived for the slug tests considering the dip of the tilted confined aquifer. When the dimensionless storage coefficient and inertial parameter were constant, the dimensionless damped coefficient of the test well-aquifer system increased with increasing dip. When the dimensionless damped coefficient calculated by the modified model differs by 10% than the value calculated by the Kipp model, the effect of the dip should be considered, and the critical dip for affecting the water head response was 34°. The difference in the analytical results between the modified and Kipp models indicates that ignoring the dip of aquifer will cause error in the estimation of the transmissivity and storage coefficient of the tilted confined aquifer.
Ensemble Kalman smoother for soil moisture data assimilation
CHU Nan, HUANG Chunlin, DU Peijun
2015, 26(2): 243-249. doi: 10.14042/j.cnki.32.1309.2015.02.012
Abstract:
To study the influence of soil texture and organic matter on soil moisture assimilation when observation data are rare, we develop a soil moisture assimilation scheme based on ensemble Kalman filter (EnKF) and ensemble Kalman smoother (EnKS). Surface soil moisture observations obtained from Arou station in the upper reaches of Heihe river basin in 2008 are assimilated into simple biosphere model 2 (SiB2) by using EnKF and EnKS respectively to analyze the influences of soil texture and organic matter and observation frequency on estimation. Results showed that influences of soil texture and organic matter on soil moisture estimation are large at surface layer but little at deep layer. Both EnKF and EnKS can significantly improve the accuracy of soil moisture estimation at surface and root zone by assimilating surface soil moisture observations, and EnKS is little better than EnKF. High accuracy of soil moisture estimation can be obtained by EnKS when observation data are scarce.
Experimental study on lid-driven cavity flow at high Reynolds number
ZHANG Jinfeng, CHANG Lu, MAA Jerome Peng-Yea
2015, 26(2): 250-256. doi: 10.14042/j.cnki.32.1309.2015.02.013
Abstract:
Laboratory experiments have been conducted to study high Reynolds number (from 1×105 to 1×106), three-dimensional lid-driven cavity flows in two cavity dimensions: 0.2m×0.2m×0.2m and 0.5m×0.5m×0.5m. Particle Image Velocimetry (PIV) technical was applied to investigate the flow field and the effects of wall on the flow fields. Measured time-averaged streamlines show that the primary eddy starts to distort at Re=5×105 and starts to breakup into two/three eddies at Re=1×106. The region of Downstream Secondary Eddy (DSE) decreases as the Reynolds number increases. At Re=5×105, a fully developed DSE can be seen clearly. But it is hard to see when Re=1×106. The thickness of boundary layer becomes thinner and thinner as the Reynolds number increases. The measurements also show that the side boundary has a significant impact of the primary eddy.
Image-based measurements of low-speed streaks in near-bed region of open channel flow
WANG Hao, LI Danxun, CHEN Qigang, WANG Xingkui
2015, 26(2): 257-264. doi: 10.14042/j.cnki.32.1309.2015.02.014
Abstract:
Image-based experiments have been conducted to measure low-speed streaks in the near-bed region of open channel flow. The measurements involve tracing the streaks with natural sand, recording the streak images by a high-resolution camera, and extracting geometrical features of the steaks through mathematical morphology procedure. Analysis of the measured data yields the following findings: ① The streak width is symmetric with respect to the midline of the bed, attaining its maximum value at the center and decreasing gradually toward the side wall; ② At friction Reynolds number from 276 to 465, the low-speed streaks vary from 20.8 to 29.8 in dimensionless width, from 99.3 to 126.7 in dimensionless interval, and from 23.4% to 15.9% in percentage area; and ③ An increase of friction Reynolds number leads to an increase in the width and interval of streaks together with a reduction in the percentage area. The experimental results indicate that image processing technique provides an efficient and accurate tool for investigating complex low-speed streaks in open channel flow.
Adaptability analysis of hydraulics research method on the bottom outlet of flood discharge with high water head
LUO Yongqin
2015, 26(2): 265-270. doi: 10.14042/j.cnki.32.1309.2015.02.015
Abstract:
The research methods of hydraulics are diverse and each method has its characteristics. It is more concerned for the similarities and differences of reached achievements from all kinds of methods. Based on the bottom outlet of flood discharge with high water head in one hydropower station, the simulation and observation are carried through for the hydraulic issues by applying the physical modeling experiment, the prototype measurement of hydraulics and the time-averaged turbulence mathematical model. The adaptable scope and degree of three kinds of methods are identified. It is identical well for the simulated results of three methods with the macroscopic hydraulic flow state, bottom flow velocity, time-averaged pressure and aerated cavity. Meanwhile, there is a certain difference in the simulation of flow profile. The fluctuation prototypical water surface and longitudinal diffusion of water jets are larger. The achievement can be used to lead the selection of research method and correction of achievement for this type of hydraulic issues.
Global sensitivity analysis of parameters in DRAINMOD-S
YU Shuang'en, WANG Ning, YU Zhiheng, WANG Jun
2015, 26(2): 271-278. doi: 10.14042/j.cnki.32.1309.2015.02.018
Abstract:
In order to efficiently select the optimized parameters in DRAINMOD-S and figure out how the parametric variation influences the simulation results, sensitivity analysis of the parameters in the model was performed. Taking the pipe drainage desalting test as an example, which was conducted in Nantong Kowloon Reclamation Area, the Morris global qualitative sensitivity analysis was adopted to detect the the parameters sensitivity simulated in DRAINMOD-S of soil salinity in the profile against six parameters, namely, lateral saturated hydraulic conductivity Ksat, hydrodynamic dispersion coefficient D, maximum depth of surface water Sm, actual distance from surface to impermeable layer Im, drainage coefficient Dr and initial groundwater depth W. The results showed that Ksat has remarkable influence on simulation followed by D, Sm, Dr, while W and Im have little influence; nonlinear interactions among the parameters are different, and Ksat is the most significant. To guarantee the quality of the model simulation, accuracies of on-site measurement should be improved for the sensitive parameters and more emphases should be put on the sensitive parameters during the modelling. Meanwhile, the parameters which have strong nonlinear interaction should not be ignored. Therefore, model parameter calibration can be guided efficiently, and the applicability of the model will be improved.
Revisions on water resources vulnerability and adaption measures under climate change
XIA Jun, SHI Wei, LUO Xinping, HONG Si, NING Like, Christopher J Gippel
2015, 26(2): 279-286. doi: 10.14042/j.cnki.32.1309.2015.02.019
Abstract:
Assessment of water resources vulnerability and development of adaption measures under climate change are among the major strategic issues for sustainable development in China. This paper reviews progress in research in this field and recommends revisions in direction and emphasis. In general, research and policy-making has so far inadequately dealt with uncertainties that exist in hydrological processes. Also, there has been a tendency for research on vulnerability assessment and adaption measures to be disjointed, while evidence suggests that water shortage that threatens social and economic development is often related to poor water management. Future research in this field would benefit by: Integration of vulnerability assessment and ecological needs with appropriate adaption measures; development of theory and models of how to respond quickly to hydrological, ecological and socio-economic change; quantifying and utilizing risk and uncertainty; adopting no regrets adaptation measures; undertaking cost-benefit analysis of options with the goal of sustainable development; and greater stakeholder involvement in information provision and decision making.
Research advances on thereasonable water resources allocation in irrigation district
QI Xuebin, HUANG Zhongdong, QIAO Dongmei, ZHANG Xianchao, LI Ping, Mathias N Andersen
2015, 26(2): 287-295. doi: 10.14042/j.cnki.32.1309.2015.02.020
Abstract:
The rational allocation of water resources for irrigation is important to improve the efficiency in utilization of water resources and ensuring food security, but also effective control measures need to be in place for the sustainable utilization of water resources in an irrigation area. The progress of research on the rational allocation of water resources in irrigation districts both at home and abroad may be summarized in four key aspects of the policy regarding water resources management: ① The mechanism of water resource cycle and ② Transformation in irrigation district, ③ The water resources optimal allocation model and ④ The hydrological ecosystem analysis in irrigation district. Our analysis showed that there are four major problems in domestic irrigation water resources allocation: Policies for rational water resources allocation and protection are not in place, unified management mechanism of water resources is not perfect, the model for optimal water resources allocation is not practical, and the basic conditions for optimal allocation of water resources is relatively weak. In order to solve those problems in water resources allocation practice, six important aspects must be the focus in China in future research: More attention need to paid to studying the unified management policy and mechanism of water resources, studying the water resources cycle and transformation under environmental change, studying new methods for water resources carrying capacity and evaluation in irrigation districts, studying the water resources control technology in irrigation districts by hydrology ecological system, studying the technologies of real-time risk dispatching and intelligent management in irrigation districts, and finally studying the technology of coupling optimal allocation technology in irrigation districts.