Investigation of sediment movement in the North Navigation Channel Area of the estuary of the Yangtze river using natural radiotracers and INAA methods

1996 ◽  
Vol 205 (2) ◽  
pp. 283-293
Author(s):  
Zhang Yunhui ◽  
Li Guiqun ◽  
Zhang Qixing ◽  
Sun Maoyi
Keyword(s):  
Yangtze River ◽  
The Yangtze River ◽  
Sediment Movement ◽  
The North ◽  
Navigation Channel

scholarly journals Temporal and Spatial Distributions of Ecological Vulnerability under the Influence of Natural and Anthropogenic Factors in an Eco-Province under Construction in China

2018 ◽  
Vol 10 (9) ◽  
pp. 3087 ◽  
Author(s):  
Qian Ding ◽  
Xun Shi ◽  
Dafang Zhuang ◽  
Yong Wang
Keyword(s):  
Yangtze River ◽  
Principal Component ◽  
Anthropogenic Factors ◽  
Land Resource ◽  
The Yangtze River ◽  
Irrigation Channel ◽  
The North ◽  
Ecological Vulnerability ◽  
Under Construction ◽  
Natural And Anthropogenic Factors

Ecological vulnerability evaluations can provide a scientific foundation for ecological environment management. Studies of ecological vulnerability have mainly focused on typical ecologically vulnerable regions with poor natural conditions or severe human interference, and such studies have rarely considered eco-provinces. Taking Jiangsu, an eco-province under construction in China, as the study area, we evaluated the spatiotemporal distributions of ecological vulnerability in 2005, 2010 and 2015 at the kilometer grid scale and analyzed the effects of natural and anthropogenic factors on ecological vulnerability. The pressure state response model (PSR), geographic information systems (GIS), spatial principal component analysis, spatial autocorrelation analysis, and correlation analysis methods were used. The results of the study are as follows: (i) the effects of anthropogenic factors on ecological vulnerability are greater than those of natural factors, and landscape evenness and the land resource utilization degree are the main factors that influence ecological vulnerability. (ii) Jiangsu Province is generally lightly to moderately vulnerable. Slight vulnerability is mainly observed in areas with water bodies. Light vulnerability is concentrated in paddy fields between the Main Irrigation Channel of North Jiangsu and the Yangtze River. Medium, heavy and extreme vulnerability areas are mainly composed of arable and built-up land. Medium vulnerability is mainly distributed to the north of the Main Irrigation Channel of North Jiangsu; heavy vulnerability is scattered to the south of the Yangtze River and in north-western hilly areas; and extreme vulnerability is concentrated in hilly areas; (iii) Ecological vulnerability displays a clustering characteristic. High-high (HH) regions are mainly distributed in heavy and extreme vulnerability regions, and low-low (LL) regions are located in slight vulnerability areas. (iv) Ecological vulnerability has gradually deteriorated. From 2005 to 2010, the vulnerability in hilly areas considerably increased, and from 2010 to 2015, the vulnerability in urban and north-eastern coastal built-up land areas significantly increased. Emphasis should be placed on the prevention and control of ecological vulnerability in high-altitude, urban and coastal areas.

scholarly journals A modeling study of the influences of Yangtze River and local catchment on the development of floods in Poyang Lake, China

2016 ◽  
Vol 47 (S1) ◽  
pp. 102-119 ◽  
Author(s):  
Xianghu Li ◽  
Jing Yao ◽  
Yunliang Li ◽  
Qi Zhang ◽  
Chong-Yu Xu
Keyword(s):  
Yangtze River ◽  
Lake Level ◽  
Poyang Lake ◽  
Hydrological Regime ◽  
The Yangtze River ◽  
Lake Level Changes ◽  
The North ◽  
Physically Based ◽  
North And South ◽  
Catchment Runoff

Poyang Lake, one of the most frequently flooded regions in China, connects with the Yangtze River and the five sub-tributaries in the local catchment. The lake's hydrological regime is complicated by a complex hydraulic connection and strong river–lake interaction, especially for the extreme hydrological regime. This study analyzes the relationships between the lake level changes and the flow regimes of Yangtze River and local catchment during the flood season and employs a physically based hydrodynamic model to quantify their relative contributions to the development of floods. The study found that the large catchment runoff and Yangtze River discharge were both significant contributors to flood development but that their contributions were unevenly distributed in time and space. The local catchment imposed more influence during the period of April–May and at the middle parts of the lake, and its influence decreased toward the north and south; in contrast, the most remarkable lake level changes were observed in July–August and at the northern lake for the Yangtze River cases, and these changes reduced from north to south. Moreover, Yangtze River imposed far stronger influences on the lake level changes than the catchment runoff and dominated the duration of floods to a great extent.

Chinese Communist Treatment of the Origins and the Foundation of the Chinese Empire

1965 ◽  
Vol 23 ◽  
pp. 78-105 ◽  
Author(s):  
A. F. P. Hulsewé
Keyword(s):  
Yangtze River ◽  
Fourth Century ◽  
Fifth Century ◽  
The Yangtze River ◽  
The South ◽  
The West ◽  
Warring States ◽  
North East ◽  
The North ◽  
Chinese Empire

In antiquity, China was far from being the China we know today, neither in extent, nor in political and social organisation. To the south it did not extend beyond the Yangtze River, to the north it stopped short of the Mongolian steppe, to the north-east, only a small part of the south Manchurian plain was included, whereas in the west it merely went up to the easternmost part of what is now Kansu Province; the Szechwan plain was only included at the end of the fourth century B.C. Politically, the King of Chou was theoretically the overlord of most of this area, but in actual practice, independent rulers reigned over a congeries of larger and smaller states. As a result of wars of conquest, seven large states had come to be formed by the middle of the fifth century B.C. and these were engaged in a ceaseless struggle for supremacy. The time between the middle of the fifth century and 221 B.C., when the western state of Ch'in finally conquered all its rivals, is known as the period of the Warring States.

The Extreme Drought Event during Winter–Spring of 2011 in East China: Combined Influences of Teleconnection in Midhigh Latitudes and Thermal Forcing in Maritime Continent Region

2013 ◽  
Vol 26 (20) ◽  
pp. 8210-8222 ◽  
Author(s):  
Dachao Jin ◽  
Zhaoyong Guan ◽  
Weiya Tang
Keyword(s):  
North Atlantic ◽  
Yangtze River ◽  
Lower Troposphere ◽  
The Philippines ◽  
Drought Event ◽  
The Yangtze River ◽  
Maritime Continent ◽  
Thermal Forcing ◽  
The North ◽  
The North Atlantic

Abstract The middle and lower reaches of the Yangtze River (MLRYR) in China experienced an extremely severe and persistent drought event from January to May of 2011. Using both the observational data and NCEP–NCAR reanalysis, features of the drought event and the related circulation anomalies were investigated. It is found that the precipitation during the investigated period of 2011 was deficient mostly along the Yangtze River. The water vapor diverged from MLRYR southward into the Bay of Bengal, South China Sea, and the Philippines. There were two factors facilitating the drought event. One was the quasi-stationary Rossby wave–related teleconnection, which propagated eastward at midhigh latitudes from the North Atlantic to East Asia, reinforcing the Siberian high and the East Asian trough, henceforth resulting in the divergence anomalies in MLRYR in the lower troposphere. This quasi-stationary wave train, though originating from the North Atlantic region, was not essentially related to the North Atlantic Oscillation. Another factor for the drought event was the persistent anomalous thermal forcing over the Maritime Continent, which induced the anomalous divergence in the upper troposphere in this region, building up an anomalous Hadley circulation with its ascent branch over the Maritime Continent and descent branch over MLRYR. This thermal forcing was possibly, but not necessarily, related to the La Niña event. The persistence of the drought event over MLRYR was due to the maintenance of the quasi-stationary waves at midhigh latitudes and the persistent anomalous thermal forcing in the Maritime Continent.

scholarly journals Modeling the Effects of Climate Change on Surface Ozone during Summer in the Yangtze River Delta Region, China

2019 ◽  
Vol 16 (9) ◽  
pp. 1528 ◽  
Author(s):  
Da Gao ◽  
Min Xie ◽  
Xing Chen ◽  
Tijian Wang ◽  
Chenchao Zhan ◽  
...  
Keyword(s):  
Yangtze River ◽  
Meteorological Factors ◽  
Yangtze River Delta ◽  
The Yangtze River ◽  
The South ◽  
Southerly Wind ◽  
The North ◽  
The Yrd ◽  
Surface O3 ◽  
The Yangtze River Delta

Future climate change can impact ozone concentrations by changing regional meteorological factors related to ozone (O3) pollution. To better understand the variations of meteorological factors and their effects on O3 formation processes under future climate conditions, we model the present and the future meteorology and air quality in summer over the Yangtze River Delta (YRD) region by using the Weather Research and Forecasting Model with Chemistry module (WRF/Chem), which is driven by the outputs of Community Climate System Model version 4 (CCSM4). The simulations predict that solar radiation, 2-m air temperature, and wind speed increase in the daytime over most of the YRD region. Absolute humidity and precipitation increase in the north and decrease in the south, while the planetary boundary layer height (PBLH) has an opposite change pattern displaying a decrease in the north and an increase in the south. The southerly wind will be strengthened in the daytime. At night, the change patterns of the meteorological factors are similar to the daytime but with small variations. Meanwhile, O3 and its precursors all increase in the north and decrease in the south. The increases of NOx, volatile organic compounds (VOC), and CO are related with the decreases of PBLH and the input effect of stronger southerly wind, while the decreases are attributed to the output effect of the stronger southerly wind. During the daytime, the increase of surface O3 in the north is dominated by the chemical processes related with the increases of solar radiation, air temperature, and O3 precursors. The decrease of surface O3 in the south is mainly caused by the transport process changing with the strengthened southerly wind. At night, the surface O3 changing the amplitude is less than the daytime. The less O3 variations at night can be attributed to an O3 titration reaction with NO, the changes in NOx concentrations, and the increases of nocturnal PBLH. With the aid of H2O2/HNO3, O3 formation in the YRD region is found to be easily affected by NOx in the future. The findings can help to understand the changing trend of O3 in the YRD region and can propose reasonable pollution control policies.

Research of Effect on the Levee by Drawdown of Caisson Foundation of the North Anchorage of Maanshan Yangtze River Bridge

2013 ◽  
Vol 779-780 ◽  
pp. 619-625
Author(s):  
Yi Liu ◽  
Yan Hua Yang ◽  
Fu Quan Ji
Keyword(s):  
Finite Element ◽  
Yangtze River ◽  
Finite Element Models ◽  
Two Dimensional ◽  
The Yangtze River ◽  
Seepage Field ◽  
Seepage Analysis ◽  
The North ◽  
Stability Against Sliding ◽  
The Stability

On account of the north anchorage of Maanshan Yangtze River bridge, the drawdown of caisson foundation may bring about new seepage field of the ground, which make soil consolidate. This paper build two-dimensional plane strain finite-element models of open caisson and the Yangtze River levee, which aim to analyze the effect on the Yangtze River levee by drawdown of the open caisson foundation. Through the seepage analysis of the open caisson foundation and the stability analysis of the slope, this paper obtain the settlement and coefficients of stability against sliding of the Yangtze River levee.

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