Cadmium and clay mineral analysis of late Pliocene–Pleistocene deposits from Jianghan Basin, central China: Implications for sedimentary provenance and evolution of the Yangtze River

Author(s):  
Yawei Li ◽  
Juxing Zhao ◽  
Chang'an Li ◽  
Chuanyi Wei ◽  
Yufen Zhang ◽  
...  
2017 ◽  
Vol 19 (2) ◽  
pp. 161-172 ◽  
Author(s):  
Yao Du ◽  
Teng Ma ◽  
Yamin Deng ◽  
Shuai Shen ◽  
Zongjie Lu

Ammonium is of anthropogenic, natural and mixed origin in surface water, aquifer and intermediate aquitard between them, respectively, within the Yangtze River Basin.


Water ◽  
2019 ◽  
Vol 12 (1) ◽  
pp. 45
Author(s):  
Huadong Shen ◽  
Zhongbo Yu ◽  
Ge Yu ◽  
Xiaoli Shi

Grain size of lake sediments is often measured in paleolimnological studies, especially investigations of past paleoclimatic and paleohydrologic changes. The implications of such measures, however, remain unclear, since watershed hydrology and the related transfer of materials to the lake are affected by local climate variables, hydrological shifts, and vegetation cover variables. Sediment from Wanghu Lake in the middle reaches of the Yangtze River have apparently been affected by land cover changes and lake-river system transitions caused by a sluice gate built at Fuchi in 1967. These changes influenced the watershed hydrology, thereby confounding paleoclimatic and paleohydrologic interpretations by proxy records in sediment cores. We collected sediment cores from the center of Wanghu Lake and analyzed trends in pollen and physical properties through sedimentary records to investigate land cover changes and hydrological transitions during the past 90 years. The grain size of the sediment core increased with precipitation and the significant relationships between pollen and grain size after 1967 indicated that sediment transfer to the lake was controlled by rainfall and land cover changes due to human-induced deforestation and farming in the lake catchment. Interestingly before 1967, there was no significant relationship between the pollen and grain size or between the precipitation and grain size, indicating that the sediment of WanghuLake was not simply from the lake catchment. The different relationships patterns before and after 1967 indicated that the sediments in the lake were not only transported following precipitation and discharge from the lake catchment but also came from the Yangtze River draining back into the lake during the flood seasons before 1967. These results highlight matters needing attention and the potential application of grain size of sediments for reconstructions of past hydro-environmental changes.


2014 ◽  
Vol 651-653 ◽  
pp. 260-264
Author(s):  
Li Min Chuan ◽  
Huai Guo Zheng ◽  
Cui Ping Tan ◽  
Su Fen Sun ◽  
Jun Feng Zhang

In this study, the input and output parameters of Phosphorus (P) for wheat production system were collected from the year 2000 to 2011 to evaluate the nutrient cycling and balances in North Central China, the Middle and Lower Reaches of the Yangtze River and Northwest China. The results showed that the P fertilizer application rates for each region were 44.5, 39.7 and 42.3 kg P/ha, the P brought from previous crop were 14.8, 1.6 and 2.6 kg/ha, and brought from seeding were 1.5, 1.0 and 0.9 kg/ha, respectively. The P input from atmospheric deposition and irrigation were considered zero. The P uptake by harvest in above-ground plant in North Central China, the Middle and Lower Reaches of the Yangtze River and Northwest China were 41.2, 53.2 and 17.0 kg/ha. As a result, the P balance in North Central China and Northwest China were both showing surplus by 19.6 and 28.8 kg/ha, and in the Middle and Lower Reaches of the Yangtze River showed deficiency. It is suggested that we need to adjust the P fertilizer input in China, in order to maintain the sustainable soil fertility and avoid the negative impact on the environment.


2021 ◽  
Vol 9 ◽  
Author(s):  
Guanshi Zhang ◽  
Xiu Zhang ◽  
Long Xie ◽  
Qi Zhang ◽  
Dongsheng Liu ◽  
...  

In this study, a survey with 4,580 residents in the Yangtze River Middle Reaches Megalopolis, central China, was conducted to assess the perceived importance of local ESs. Then, principal component analysis was used to identify their perceived coincidence (i.e., ES bundles), and an automatic linear model was used to reveal how the perceived ES importance and ES bundles were associated with socioenvironmental factors, including demographics, environmental awareness, and living environment. Our results showed that the provisioning ESs, especially water supply, had relatively higher perceived importance. There was no significant difference in perceived ES importance and ES bundles between experts and ordinary residents; thus, experts may recommend practices that meet the local residents’ wishes in the YRMRM. In addition, we disclosed three bundles of perceived ES (i.e., green environment service bundle, ecological stability service bundle, and grain service bundle), which encompassed ES from different ES categories. Potential tradeoff existed in different ES bundles, mainly due to the divergent preferences of different residents. For example, residents with more bus services near the residence tended to perceive green environment service bundle as more important, but perceive ecological stability service bundle as less important. This study adds important first-hand empirical data to the field of the public preferences of local residents for a region of high economic and ecological importance in China, which could provide more information and scientific basis for socially just and sustainable region environmental planning and management.


2018 ◽  
Vol 11 (1) ◽  
pp. 55 ◽  
Author(s):  
Jieming Chou ◽  
Tian Xian ◽  
Wenjie Dong ◽  
Yuan Xu

Understanding the temporal and spatial distribution in disasters plays an important role in disaster risk management. The present study aims to explore the long-term trends in drought and floods over China and estimate the economic losses they cause. A peak-over-threshold approach is used to identify flood peaks, and the relationship between the disasters and climate indices is investigated using Poisson regression. The major results are as follows: (1) the northeastern part of China was severely affected by drought disasters (average damaged area was 6.44 million hectares); (2) the northern part of East China and Central China upstream of the Yangtze River were severely affected by flood disasters (average damaged area was 3.97 million hectares); (3) in the Yangtze River Basin, there are increasing trends in terms of drought and extreme precipitation, especially upstream of the Yangtze River, accompanied by severe disaster losses; and (4) by combining the trends in drought and extreme precipitation days with the spatial distribution of damaged areas, the study indicates that the increasing trend in droughts has shifted gradually from north to south, and the increasing trend in extreme precipitation gradually has shifted from south to north.


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