Hydrological Research in China:
Process Studies, Modelling Approaches and Applications
Edited by Dawen Yang, Fuqiang Tian, Lihua Tang & Zhiyu Liu
IAHS Publ. 322 (2008)ISBN978-1-901502-64-0, 262 + x pp. Price £55.00 (includes postage worldwide)
Climate in China varies from arid to semi-arid and semi-humid to humid, inducing a variety of hydrological phenomena. The Chinese population has tripled during the last 50 years, to reach 1.3 billion. Under the pressure of the increasing population, in northern China the scarcity of water resources is becoming a bottleneck for social and economic development, and has led to the widespread degradation of natural ecosystems and the environment, while in southern China flooding is a great threat and the potential risks are increasing steadily. Accurate predictions of droughts and floods are extremely important to these regions. China is changing from traditional water resources development to water resources management for sustainable development,and needs advanced hydrology for this. The contributions here were selected from an International PUB (Predictions in Ungauged Basins) meeting in China, and provide a cross-section of the innovative research there.CONTENTS
Preface by Dawen Yang, Fuqiang Tian, Lihua Tang & Zhiyu Liu
1Process studies
Evaporation paradox in the Yellow River Basin, China Zhentao Cong, Dawen Yang, Fubao Sun & Guangheng Ni
Evaluating the advection-aridity model of evaporation using data from field-sized surfaces of HEIFE Songjun Han, Heping Hu & Fuqiang Tian
An improved analytical approach to estimate in situbiodegradation rates Yuan Liu & Xiaofeng Wu
Estimating unsaturated soil hydraulic parameters using a generalized Richards equation Haishen Lü, Yonghua Zhu & Zhongbo Yu
Computation ofgrid storage capacity from topographic index in hydrological modelling Peng Shi, Xiaofang Rui, Simin Qu & Xi Chen
A tracer experimentand numerical simulation of potential nitrogen pollution from agricultural fertilization Lihua Tang, Sicong Zhang & Xiufen Sun
Assessing the effects of different cropping patterns on drainage capability of the southern riverine basin Fengyan Wu & Tiesong Hu
Possible impact of aerosols on orographic precipitation in eastern China Hanbo Yang, Dawen Yang, Pingyun Li & Yafei Wang
Estimating dry matter content for winter wheat using MODIS reflectance data Yonghong Yi, Dawen Yang & Daoyi Chen
2Modelling approach
A large-scale routing scheme for stream simulation and its application to river basins in China FengChen & ZhenghuiXie
Investigation of organized hydrological heterogeneity from a spatial analysis perspective Hongyi Li & Murugesu Sivapalan
Appropriatecontributing area threshold of a digital river network extracted from DEM for hydrological simulation Li Li, Jiahu Wang & Zhenchun Hao
A statistically-based runoff-yield model Zhongmin Liang, Jun Wang, Yang Lei & Ye Shi
Uncertainty estimation for the Xin’anjiang model parameters Fanggui Liu, Xiaofang Rui, Hehai Xie, Jie Feng & Jiyu Yu
Generation of triangulated irregular networks for distributed hydrological modelling Guangheng Ni, Lei Wang, Fuqiang Tian & Heping Hu
Scale and resolution effects of topographic index by 2-D continuous wavelet transform Dingbao Wang & Ximing Cai
A long-term runoff forecast model based on association rules of data mining
Fuqiang Wang & Shiguo Xu
A macro-scale hydrological model based on a spatial averaging approach: model structure and an application Zhiyong Yang, Heping Hu Fuqiang Tian
Assessment of hydrological model structure based on parameter identifiability
Hongli Zhao, Xiaoliu Yang & Yunzhong Jiang
Uncertainty of the box-counting method for estimating the fractal dimension of river networks Miao Zhou, Fuqiang Tian & Heping Hu
3Applications
A variable fuzzy-sets assessment modeland its application to regional water resources assessment Shouyu Chen, Chunling Chai & MinLi
Implementation of subgrid-scale spatial variability of parameters in a regional climate–hydrology coupled model Xing Chen, ZhongboYu, Yong Huang, Guangbai Cui,
LiliangRen Xi Chen
Impacts of climate change on hydrological processes and water resources in the headwater area of the Yellow River Hui Gao, Yangwen Jia, Cunwen Niu,
Yaqin Qiu & Hao Wang
Ecological water resources requirement of the Ningxia natural oasis using the groundwater level variation amplitude method Xiaorong Huang, Xinhai Zhang & Caiwang Zhai
Mapping the average annual runoff depth in Huangshui watershed using DEM
Shaofeng Jia, Shijun Lin & Yajun Wang
2-D hybrid approach to storm flood modelling in the Shalan catchment
Chong Li, Jikang Lu & Baisheng Ye
The uncertaintyanalysis of the wetted perimeter method via axis scaling for setting minimum ecological in-stream flow requirements Suxia Liu, Xingguo Mo, Jun Xia, Changming Liu & Lina Ji
Temporal and spatial variations of 18O along the main stem of the Yangtze River, China Baohong Lu, Tingting Sun, Chunyan Wang, Su Dai, Jian Kuang & Jiyang Wang
Genetic algorithm based combined evaluation model for regional water security evaluation: a case study Fang Tong & Zengchuan Dong
Comparing univariate ARMA and ARFIMA model for forecasting daily streamflows Wen Wang, XiChen, JunMa & Shiqing Huo
Effects of land use changes on hydrological responses of the MekongRiver
Shan Xie, Tianqi Ao, Lingling Wu & Wei Feng
Analysis of water resources variability in the Yellow River of China using a distributed hydrological model Dawen YangWeiwei Shao
Application of the grey self-memoryneural network model for annual runoff forecasting Xiaowei Zhang, Lingmei Huang &Bing Shen
Study on countermeasures for water resources shortage and changes of ecological environment in ShiyangRiver basin Yongming Zhang, Jun Jiang, Bing Shen
Qingling Shen
Determination of root-zone water storage in a desert woodland using a two-layer moisture balance model Yonghua Zhu, Liliang Ren, Haishen Lü & T. H. Skaggs
Impact of climate change on the streamflow in the headwater catchment of the YellowRiver basin Fangfang Zhao, ZongxueXu & Junxiong Huang
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Hydrological Research in China: Process Studies, Modelling Approaches and Applications (Proceedings of Chinese PUB International Symposium, Beijing, September 2006). IAHS Publ. 322, 2008, 3-8.
Evaporation paradox in the YellowRiver Basin, China
Zhentao CONG, Dawen YANG, Fubao SUN & Guangheng NI
Department of Hydraulic Engineering, TsinghuaUniversity, Beijing 100084, China
Abstract It is well known that the surface of the Earth has warmed over the past 50 years. It is generally expected that the air will become drier and that evaporation will increase. However, many observations show that pan evaporation has been steadily decreasing all over the world. The contrast is called the evaporation paradox. Using climate data from 140 weather stations and hydrological data from 71 stations, it was found that potential evaporation, both pan evaporation and reference potential evaporation, show a significant decreasing trend, which indicates that the evaporation paradox does exist in the Yellow River Basin. At the same time, actual evaporation estimated by water balance decreased with the decrease in precipitation in most sub-basins. With the increase of precipitation, potential evaporation and actual evaporation have a complementary relationship; while based on yearly results, potential evaporation and actual evaporation have a proportional relationship.
Key words evaporation paradox; Yellow River; potential evaporation; actual evaporation; evaporation
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Hydrological Research in China: Process Studies, Modelling Approaches and Applications (Proceedings of Chinese PUB International Symposium, Beijing, September 2006). IAHS Publ. 322, 2008, 9-14.
Evaluating the advection-aridity model of evaporation using data from field-sized surfaces of HEIFE
Songjun HAN, Heping HU & Fuqiang TIAN
State Key Laboratory of Hydro-science and Engineering, Department of Hydraulic Engineering, TsinghuaUniversity, Beijing 100084, China
Abstract The advection-aridity model for estimating daily evaporation is evaluated using the data of the HEIFE experiment. In the dimensionless form of the model, the evaporation ratio (the ratio of the actual evaporation (E) to Penman potential evaporation (E0)) is expressed as a linear function of the proportion of the radiation term (Erad) in E0. Because the value of the evaporation ratio is between 0 and 1, the advection-aridity model is only applicable under a certain range of Erad /E0, and the applicability of the model is influenced by the water availability of the surfaces implied by Erad /E0 from atmospheric conditions. The calculated evaporation ratio is negative for small values of Erad /E0, and is larger than 1 for large values of Erad /E0. Significant systemic bias would be presented if the advection-aridity model underestimated the actual evaporation under dry conditions and overestimated under wet conditions. A comparison between the reference values of the mean daily evaporation of the Gobi desert and oasis surfaces obtained by the eddy correlation method and evaporation estimates from the advection-aridity model validated the analysis.
Key words complementary relationship; advection-aridity model; HEIFE
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Hydrological Research in China: Process Studies, Modelling Approaches and Applications (Proceedings of Chinese PUB International Symposium, Beijing, September 2006). IAHS Publ. 322, 2008, 15-21.
An improved analytical approach to estimate in situbiodegradation rates
Yuan LIU & Xiaofeng WU
Institute of Hydrology & Water Resources, State Key Laboratory of Hydroscience and Engineering,
TsinghuaUniversity, Beijing 100084, China
AbstractBiodegradation is a major process in reducing most organic contaminants in aquifers. Estimation of in situ biodegradation rates is significant for studying the natural attenuation of contaminants in the field. Buscheck & Alcantar (1995) have developed a method based on field data to estimate biodegradation rates for 1-dimensional (1-D) steady-state plumes. However, in simplifying a field plume, which is usually 2- or 3-D, into a 1-D case, a certain degree of error will occur.In this paper, case studies are performed to assess the errors caused by such simplification. Moreover, an improved analytical method is suggested in steps. Application of the newly developed analytical approach to a field site gives quite good agreement.
Key words biodegradation rate;groundwater contaminant
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Hydrological Research in China: Process Studies, Modelling Approaches and Applications (Proceedings of Chinese PUB International Symposium, Beijing, September 2006). IAHS Publ. 322, 2008, 22-27.
Estimating unsaturated soil hydraulic parameters using a generalized Richards equation
Haishen LÜ, Yonghua ZHU & Zhongbo YU
State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering, Department of Applied Mathematics,HohaiUniversity, Naijing 210098, China
Abstract Richards equation is widely used as the basis for simulations of water transport in soils. For infiltration into horizontal soil columns, Richards equation predicts that the water content profile is a unique function of the Boltzmann variable (distance)/(time)q, where q = 0.5. However, a number of experiments have found that q is significantly less than 0.5. Scaling with q < 0.5 is consistent with a generalized Richards equation that uses a fractional time derivative of the water content.In this paper we consider a generalized Richards equation that incorporates the unsaturated hydraulic conductivity function k(h) of van Genuchten (1980).A new method is proposed for estimating the van Genuchten parameters α and n. Estimates of α and n are expressed as closed form equations that are functions of other parameters such as the length of wetted zone, the sorptivity, and the saturated hydraulic conductivity.
Key words generalized Richards equation; unsaturated hydraulic conductivity function
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Hydrological Research in China: Process Studies, Modelling Approaches and Applications (Proceedings of Chinese PUB International Symposium, Beijing, September 2006). IAHS Publ. 322, 2008, 28-32.
Computation ofgrid storage capacity from topographic index in hydrological modelling
Peng SHI1, Xiaofang RUI2, SiminQU2 XiCHEN1
1State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering, Nanjing 210098, China
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2College of Water Resources and Environment, HohaiUniversity, Nanjing 210098, China
Abstract Recent advances in the field of GIS have made possible thedevelopment of distributed hydrological models. However, there are some unsolved problems in full real-time distributed hydrological models. In view of these problems, an alternative conceptual distributed hydrological model is proposed in this paper. Determination of water storage capacity for every grid cellhas become an important problem in conceptual distributed hydrological models; taking the similarity between the maximum grid soil moisture deficiency and the grid topographic index into account, it was found that a logarithmic Weibull function relationship exists between them. Based on this, a method to calculate the grid storage capacity from the grid topographic index is proposed. The method was applied in a grid distributed hydrological model with non-compact structure.Resultsobtained show that in an ungauged basin it is possible to get some of the hydrological parameters from the geographic parameter set. The main conclusion of this paper is that the findings here suggest a promising alternative way for hydrological modelling.
Key words distributed hydrological model; topographic index; grid storage capacity; logarithmic Weibull function
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Hydrological Research in China: Process Studies, Modelling Approaches and Applications (Proceedings of Chinese PUB International Symposium, Beijing, September 2006). IAHS Publ. 322, 2008, 33-40.
A tracer experimentand numerical simulation of potential nitrogen pollution from agricultural fertilization
Lihua TANG1,2, SicongZHANG1,2 Xiufen SUN1
1 Department of Hydraulic Engineering, TsinghuaUniversity, Beijing100084, China
2 State Key Laboratory of Hydroscience and Engineering, TsinghuaUniversity, Beijing 100084, China
Abstract Agricultural non-point source pollution is probably the most significant anthropogenic source of nitrogen pollution for water bodies. The excessive fertilizers rushed into surface water bodies by runoff or leached into groundwater by percolation may cause eutrophication or groundwater pollution. It is usually difficult to estimate the non-point source pollution due to its random and distributed nature. In this paper, a winter wheat potted-planting experiment was carried out, and the fertilizer with added 15Nas the tracer was added to soil. By examining the nitrogen contents in soil and crop samples during the wheat growth period, the fate of fertilizer nitrogen was analysed, and the potential pollution fertilizer left in soil was estimated. In order to analyse the fertilization and irrigation effects on nitrogen losses, a one-dimensional model, LEACHM(Leaching Estimation And CHemistry Model), was adapted to simulate the nitrogen transport in the agricultural soil profile. The results showed that soil nitrate nitrogen increased significantly after wheat planting, which may result in a high probability of nitrogen losses by runoff or leaching, and therefore excessive fertilization and irrigation may increase nitrogen losses as well as cause a high risk of nitrogen pollution.
Key words tracing experiment; non-point source pollution; agricultural fertilization; LEACHM model
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Hydrological Research in China: Process Studies, Modelling Approaches and Applications (Proceedings of Chinese PUB International Symposium, Beijing, September 2006). IAHS Publ. 322, 2008, 41-47.
Assessing the effects of different cropping patterns on drainage capability of the southern riverine basin
Fengyan WU1Tiesong HU2
1Hubei Water Resources Research Institute, Hubei430070, China
2State Key Laboratory of Water Resources and Hydropower Engineering Science of WuhanUniversity, Wuhan 430072, China
Abstract Compared with natural watersheds, only a few studies have been conducted to take the specific characteristics of farmed watersheds into account in hydrological modelling. The purpose of this paper is to develop a conceptual rainfall–runoff model with which both the impact of human activities on flood events and the effects of different cropping patterns on drainage capability of the southern riverine basin could be assessed, especially the existence of drainage practices and ditch networks. Applications of the model are demonstrated for Luoshan drainage basin, which is located in HubeiProvince. To analyse the role of cropping patterns, six hypothetical scenarios are discussed. Results show that the drainage system of Luoshan drainage basin can dispose of the excess water from 3-day rainfall totals, with return periods of 6.9 years in five days and with the area of paddy fields being increased, the drainage capability would be strengthened.
Keywords cropping patterns; drainage capability; rainfall–runoff model; Luoshan
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Hydrological Research in China: Process Studies, Modelling Approaches and Applications (Proceedings of Chinese PUB International Symposium, Beijing, September 2006). IAHS Publ. 322, 2008, 48-53.
Possible impact of aerosols on orographic precipitation in eastern China
Hanbo YANG1, Dawen YANG1, Pingyun LI2 & Yafei WANG2
1State Key Laboratory of Hydro-Science and Engineering & Department of Hydraulic Engineering,
TsinghuaUniversity, Beijing 100084, China
2State Key Laboratory of Severe Weather, ChineseAcademy of Meteorological Sciences, Beijing 100081, China
Abstract To analyse the possible suppression by aerosols of orographic precipitation, three catchments were chosen in eastern China. The suppression was quantified as change in the orographic precipitation enhancement factor (Ro), defined as the ratio between the hilly and the plains precipitation. The results show a significant downward trend ofRo in the past 50 years, accompanied by a decrease in visibility (indicating an increase in aerosols concentration). During the period from 1980 to 2002, the three catchments had a decrease in Ro, with a rate of 22–42% and an increase in the aerosols concentration, with a rate of approx. 0.01–0.02 mg/m3 (10–30%). It is speculated that the possible cause of Ro decreasing is the increase in aerosols concentration, and this implies the loss of significant water resources in hilly areas, which may be a reason for aggravation of the water resources shortage, especially in north China and northeast China.
Key words orographic precipitation; enhancement factor; aerosols; visibility
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Hydrological Research in China: Process Studies, Modelling Approaches and Applications (Proceedings of Chinese PUB International Symposium, Beijing, September 2006). IAHS Publ. 322, 2008, 54-62.
Estimating dry matter contentfor winter wheat using MODIS reflectance data
Yonghong YI1, Dawen YANG1Daoyi CHEN2
1State Key Laboratory of Hydroscience and Engineering, Department of Hydraulic Engineering, TsinghuaUniversity, Beijing 100084, China
2Department of Engineering, University of Liverpool, LiverpoolL69 3BX, UK
Abstract The accumulation process of dry matter content during the crop growing period is a good indicator of crop condition and yield. This paper investigated the application of remote sensing in estimating the dry matter content. Several vegetation indices (VI) calculated from the MODIS 500 m reflectance data were used for regression analysis. A negative correlation was found between all the VIs and the dry matter content after the VIsreached the peak. This correlation during the later growth period may be more valuable for NPP estimation since the dry matter content was then directly related to the crop yield. However, the daily VI time series were found to be very sensitive to atmospheric conditions and angular effects, which may cover the changes on the VI induced by the crop growth to a certain degree. The Savitzky-Golay filter was employed to smooth the daily NDVI time-series as a test. The smoothed NDVI temporal curves were found closer to the 8-day composite ones. The correlation between the dry matter content and NDVI was also improved after smoothing. Both of these demonstrated that this method could partly remove the noise in the MODIS data, specifically the cloud effect, and disclose the changes in NDVI from the crop growth.