Annual runoff change in the headstream of Yangtze River and its relation to precipitation and air temperature

2012 ◽  
Vol 44 (5) ◽  
pp. 850-874 ◽  
Author(s):  
Lihua Xiong ◽  
Kunxia Yu ◽  
Honggang Zhang ◽  
Liping Zhang
Keyword(s):  
Air Temperature ◽  
Yangtze River ◽  
River Flow ◽  
Annual Runoff ◽  
Climatic Conditions ◽  
The Yangtze River ◽  
Runoff Generation ◽  
Runoff Change ◽  
Runoff Series ◽  
Seasonal Analysis

We analyse the change trends of the annual and seasonal runoff series of the hydrological station Batang on the headstream of the Yangtze River over the period 1960–2007. The relations between runoff series and precipitation and temperature conditions are investigated, and the influence of the refreezing process of meltwater of the glaciers on the Yangtze River flow is examined with the proposed accumulated temperature deficit (ATD) index. It is found that annual runoff at the Batang station is not stable during the period 1960–2007. From 1960 to 1980, there was a rather strong decrease of 14.4 m3 s−1 year−1 on average in spite of the statistically significant increase in air temperature and rather stable precipitation. It is argued that the annual rate of glacier runoff generation is possibly controlled by the ATD rather than by the direct air temperature. Seasonal analysis indicates that ATD might be of greater influence in autumn and winter in affecting runoff than in spring and summer. The research in this paper may be helpful in understanding how the hydro-climatic conditions affect runoff generation in the cold regions.

Application of unstructured grid finite-volume coastal ocean model (FVCOM) to the Yangtze River hypoxic zone

2016 ◽  
Vol 26 (8) ◽  
pp. 2410-2418 ◽  
Author(s):  
Zhanhong Wan ◽  
Zongfu Ren ◽  
Xiaochun Wang ◽  
Honghao Zheng
Keyword(s):  
Finite Volume ◽  
Yangtze River ◽  
River Flow ◽  
Ocean Model ◽  
Trade Wind ◽  
Freshwater Flux ◽  
The Yangtze River ◽  
Content Type ◽  
Factors Affecting ◽  
Coastal Ocean Model

Purpose To observe the relations between three important factors resulting in estuarial Hypoxia phenomena of Yangtze River – wind, river flow, and stratification. The purpose of the paper is to analyze the possible reasons why hypoxia occurs in late spring and disappears in October. Design/methodology/approach To overcome the difficulty in examining the role of physical and biological factors affecting hypoxia based on measurement alone, finite-volume community ocean model (FVCOM) was introduced into the investigation. Observed freshwater flux data from Yangtze River, monthly averaged wind speed data, and other observed data were input into the model; the accuracy of which was validated with various kinds of data. The authors used the trajectories of Lagrangian particles from Yangtze River to study the regions of strong riverine influence under different wind forcing conditions and compared the simulation results with former observations. Findings Trade wind is a significant factor to influence the forming and receding of hypoxia across the Yangtze River. Originality/value Using FVCOM to investigate estuary hypoxia is more economical and effective.

scholarly journals The Spatiotemporal Variations of Runoff in the Yangtze River Basin under Climate Change

2018 ◽  
Vol 2018 ◽  
pp. 1-14 ◽  
Author(s):  
Ziwei Xiao ◽  
Peng Shi ◽  
Peng Jiang ◽  
Jianwei Hu ◽  
Simin Qu ◽  
...  
Keyword(s):  
River Basin ◽  
Yangtze River ◽  
Yangtze River Basin ◽  
Annual Runoff ◽  
Sensitivity Analyses ◽  
The Yangtze River ◽  
The Yangtze River Basin ◽  
The Impact ◽  
Lower Stream ◽  
Precipitation And Temperature

A better understanding of the runoff variations contributes to a better utilization of water resources and water conservancy planning. In this paper, we analyzed the runoff changes in the Yangtze River Basin (YRB) including the spatiotemporal characteristics of intra-annual variation, the trend, the mutation point, and the period of annual runoff using various statistical methods. We also investigated how changes in the precipitation and temperature could impact on runoff. We found that the intra-annual runoff shows a decreasing trend from 1954 to 2008 and from upper stream to lower stream. On the annual runoff sequence, the upstream runoff has a high consistency and shows an increasing diversity from upper stream to lower stream. The mutation points of the annual runoff in the YRB are years 1961 and 2004. Annual runoff presents multitime scales for dry and abundance changes. Hurst values show that the runoffs at the main control stations all have Hurst phenomenon (the persistence of annual runoff). The sensitivity analyses of runoff variation to precipitation and temperature were also conducted. Our results show that the response of runoff to precipitation is more sensitive than that to temperature. The response of runoff to temperature is only one-third of the response to precipitation. A decrease in temperature may offset the impact of decreasing rainfall on runoff, while an increase in both rainfall and temperature leads to strongest runoff variations in the YRB.

Linear and non-linear scaling of the Yangtze River flow

2008 ◽  
Vol 22 (10) ◽  
pp. 1532-1536 ◽  
Author(s):  
Guojie Wang ◽  
Buda Su ◽  
Zbigniew W. Kundzewicz ◽  
Tong Jiang
Keyword(s):  
Yangtze River ◽  
River Flow ◽  
Linear Scaling ◽  
The Yangtze River ◽  
Non Linear

scholarly journals Effects of Land Use/Cover Change On Atmospheric Humidity in Three Urban Agglomerations in The Yangtze River Economic

2021 ◽  
Author(s):  
Baoni Li ◽  
Lihua Xiong ◽  
Quan Zhang ◽  
Shilei Chen ◽  
Han Yang ◽  
...  
Keyword(s):  
Land Use ◽  
Air Temperature ◽  
Land Surface ◽  
Yangtze River ◽  
Urban Expansion ◽  
Regional Climate ◽  
Urban Land ◽  
The Yangtze River ◽  
Atmospheric Humidity ◽  
Urban Agglomerations

Abstract Land use/cover change (LUCC) affects regional climate not only through its direct changes of land surface properties, but also through its further modifications of land-atmosphere interactions. Urban land expansion is a typical case of LUCC in highly populated areas, and has been widely discussed about its impacts on regional air temperature, notably known as urban heat island (UHI) effects. Besides air temperature, atmospheric humidity, as another key variable in hydrometeorology and climate, would be inevitably affected by LUCC as well. However, the impacts of LUCC on atmospheric humidity seem to have not been investigated as much as on temperature. We examined atmospheric humidity changes by trend analyses of humidity indicators in three representative urban agglomerations in the Yangtze River Economic Belt (YREB), China during 1965-2017, and found the evident urban dry island (UDI) effects which are characterized by significant humidity decrease and vapor pressure deficit increase. In different urban cores, the severity levels of UDI are different. Furthermore, strong positive correlations between humidity and evapotranspiration, and between evapotranspiration and leaf area were detected during 2001-2017 when cities entered the accelerated stage of land expansion, indicating that LUCC affects regional climate through an ecohydrological way. We speculated that the UDI effect will not appear until urban land expands to a certain scale. Besides, the UHI effect emerged in the early stage of urban expansion, about 5 years earlier than the UDI effect, and has not performed prominently in recent years. This implies that urbanization-induced LUCC may exert a larger influence on UDI than on UHI in the current later period of urban expansion.

scholarly journals Simulating the Regional Impacts of Urbanization and Anthropogenic Heat Release on Climate across China

2012 ◽  
Vol 25 (20) ◽  
pp. 7187-7203 ◽  
Author(s):  
Jin-Ming Feng ◽  
Yong-Li Wang ◽  
Zhu-Guo Ma ◽  
Yong-He Liu
Keyword(s):  
Heat Flux ◽  
Heat Release ◽  
Air Temperature ◽  
Yangtze River ◽  
Surface Air Temperature ◽  
Yangtze River Delta ◽  
Anthropogenic Heat ◽  
The Yangtze River ◽  
Regional Impacts ◽  
The Yangtze River Delta

Abstract Together with economic development and accelerated urbanization, the urban population in China has been increasing rapidly, and anthropogenic heat released by large-scale energy consumption in cities is expected to be a vital factor affecting the climate. In this paper, the Weather Research and Forecasting (WRF) model coupled with the Urban Canopy Model (UCM) is employed to simulate the regional impacts on climate under the two scenarios: the underlying surface changes due to urbanization (USCU) and anthropogenic heat release (AHR). Three experiments were performed from December 2006 to December 2008. With respect to the USCU, the surface albedo and the available surface soil water decrease markedly. With the inclusion of AHR, the two scenarios give rise to increased surface temperatures over most areas of China. Especially in the urban agglomeration area of the Yangtze River delta, the combination of USCU and AHR could result in an increase of 2°C in the surface air temperature. The influence of AHR on surface air temperature in winter is greater than the influence of USCU without considering any extra sources of heat, but the opposite is found in summer. The combination of USCU and AHR leads to changes in the surface energy budget. They both increase sensible heat flux, but USCU decreases latent heat flux significantly, and AHR increases latent heat flux slightly. Nevertheless, under the influence of these two scenarios, the precipitation increases in some areas, especially in the Beijing–Tianjin–Hebei region, while it decreases in other areas, most notably the Yangtze River delta.

scholarly journals Modal analysis of annual runoff volume and sediment load in the Yangtze river-lake system for the period 1956–2013

2017 ◽  
Vol 76 (1) ◽  
pp. 1-14 ◽  
Author(s):  
Huai Chen ◽  
Lijun Zhu ◽  
Jianzhong Wang ◽  
Hongxia Fan ◽  
Zhihuan Wang
Keyword(s):  
Yangtze River ◽  
Sediment Load ◽  
Poyang Lake ◽  
Southern Oscillation ◽  
Annual Runoff ◽  
Dongting Lake ◽  
Spectrum Estimation ◽  
The Yangtze River ◽  
Runoff Volume ◽  
Lake System

This study focuses on detecting trends in annual runoff volume and sediment load in the Yangtze river-lake system. Times series of annual runoff volume and sediment load at 19 hydrological gauging stations for the period 1956–2013 were collected. Based on the Mann-Kendall test at the 1% significance level, annual sediment loads in the Yangtze River, the Dongting Lake and the Poyang Lake were detected with significantly descending trends. The power spectrum estimation indicated predominant oscillations with periods of 8 and 20 years are embedded in the runoff volume series, probably related to the El Niño Southern Oscillation (2–7 years) and Pacific Decadal Oscillation (20–30 years). Based on dominant components (capturing more than roughly 90% total energy) extracted by the proper orthogonal decomposition method, total change ratios of runoff volume and sediment load during the last 58 years were evaluated. For sediment load, the mean CRT value in the Yangtze River is about −65%, and those in the Dongting Lake and the Poyang Lake are −92.2% and −87.9% respectively. Particularly, the CRT value of the sediment load in the channel inflow of the Dongting Lake is even −99.7%. The Three Gorges Dam has intercepted a large amount of sediment load and decreased the sediment load downstream.

scholarly journals Investigating the Complexity of Runoff Series in the Yangtze River Using Sample Entropy

10.29007/ttss ◽  
2018 ◽  
Author(s):  
Yuankun Wang ◽  
Dong Wang ◽  
Xiaorui Shi
Keyword(s):  
Yangtze River ◽  
Dynamic Change ◽  
Negative Relationship ◽  
Sliding Window ◽  
Sample Entropy ◽  
Spatial Difference ◽  
The Yangtze River ◽  
Runoff Series ◽  
Increasing Trend

Based on sample entropy, we investigated spatial distribution and dynamic change of runoff series complexity with the long-term daily runoff series of main stem in the Yangtze River. The results showed that, complexity of the runoff series show an obvious spatial difference, and an increasing trend from upstream to downstream in the Yangtze River. There are negative relationship between average of runoff sliding window and the corresponding sample entropy, and their peak-to-valley value shows the well corresponding relationships. Complexity of the runoff series at Yichang and Datong stations show a continuous increasing trend, while that of Hankou station an increasing trend after 2000. It could provide scientific reference for understanding of runoff series dynamic evolution in the Yangtze River.

scholarly journals Impact of the operation of cascade reservoirs in upper Yangtze River on hydrological variability of the mainstream

2018 ◽  
Vol 379 ◽  
pp. 421-432
Author(s):  
Xu Changjiang ◽  
Zhang Dongdong
Keyword(s):  
Yangtze River ◽  
Annual Runoff ◽  
Practical Significance ◽  
Efficient Operation ◽  
Cascade Reservoirs ◽  
Hydrological Variability ◽  
Upper Yangtze River ◽  
Runoff Series ◽  
The Impact ◽  
Hydrological Station

Abstract. As the impacts by climate changes and human activities are intensified, variability may occur in river's annual runoff as well as flood and low water characteristics. In order to understand the characteristics of variability in hydrological series, diagnosis and identification must be conducted specific to the variability of hydrological series, i.e., whether there was variability and where the variability began to occur. In this paper, the mainstream of Yangtze River was taken as the object of study. A model was established to simulate the impounding and operation of upstream cascade reservoirs so as to obtain the runoff of downstream hydrological control stations after the regulation by upstream reservoirs in different level years. The Range of Variability Approach was utilized to analyze the impact of the operation of upstream reservoirs on the variability of downstream. The results indicated that the overall hydrologic alterations of Yichang hydrological station in 2010 level year, 2015 level year and the forward level year were 68.4, 72.5 and 74.3 % respectively, belonging to high alteration in all three level years. The runoff series of mainstream hydrological stations presented variability in different degrees, where the runoff series of the four hydrological stations including Xiangjiaba, Gaochang and Wulong belonged to high alteration in the three level years; and the runoff series of Beibei hydrological station in 2010 level year belonged to medium alteration, and high alteration in 2015 level year and the forward level year. The study on the impact of the operation of cascade reservoirs in Upper Yangtze River on hydrological variability of the mainstream had important practical significance on the sustainable utilization of water resources, disaster prevention and mitigation, safe and efficient operation and management of water conservancy projects and stable development of the economic society.

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