Study on the Relationship between Environmental Change and Famine Occurrence in the Middle Reaches of the Yellow River in Ancient Times

2008 ◽  
Vol 25 (1) ◽  
pp. 145-150 ◽  
Author(s):  
Li-hui QIU
2004 ◽  
Vol 117 (1) ◽  
pp. 35-40 ◽  
Author(s):  
Zhenke Zhang ◽  
Sumin Wang ◽  
Xiangdong Yang ◽  
Fuchu Jiang ◽  
Ji Shen ◽  
...  

2021 ◽  
Vol 13 (23) ◽  
pp. 4926
Author(s):  
Minzhe Fang ◽  
Guoxin Si ◽  
Qiang Yu ◽  
Huaguo Huang ◽  
Yuan Huang ◽  
...  

Achieving carbon neutrality is a necessary effort to rid humanity of a catastrophic climate and is a goal for China in the future. Ecological space plays an important role in the realization of carbon neutrality, but the relationship between the structure of vegetation ecological space and vegetation carbon sequestration capacity has been the focus of research. In this study, we extracted the base data from MODIS products and other remote sensing products, and then combined them with the MCR model to construct a vegetation ecospatial network in the Yellow River Basin in 2018. Afterward, we calculated the topological indicators of ecological nodes in the network and analyzed the relationship between the carbon sequestration capacity (net biome productivity) of ecological nodes and these topological indicators in combination with the Biome-BGC model. The results showed that there was a negative linear correlation between the betweenness centrality of forest nodes and their carbon sequestration capacity in the Yellow River Basin (p < 0.05, R2 = 0.59). On the other hand, there was a positive linear correlation between the clustering coefficient of grassland nodes and their carbon sequestration capacity (p < 0.01, R2 = 0.49). In addition, we briefly evaluated the vegetation ecospatial network in the Yellow River BASIN and suggested its optimization direction under the background of carbon neutrality in the future. Increasing the carbon sequestration capacity of vegetation through the construction of national ecological projects is one of the ways to achieve carbon neutrality, and this study provides a reference for the planning of future national ecological projects in the Yellow River Basin. Furthermore, this is also a case study of the application of remote sensing in vegetation carbon budgeting.


2016 ◽  
Vol 19 (1) ◽  
pp. 138-155 ◽  
Author(s):  
Jianxia Chang ◽  
Jie Wei ◽  
Yimin Wang ◽  
Meng Yuan ◽  
Jiacheng Guo

Runoff in the Yellow River (YR) of China is steadily declining due to climate change and human activities. In this study, the basic trend and abrupt changes of precipitation at 63 meteorological stations and runoff as measured at six hydrological stations from 1956 to 2010 are analyzed. Results indicate that 38 stations exhibit negative precipitation trends. These stations are mainly located in the lower reaches. All six hydrological stations exhibit declining runoff trends. Abrupt runoff changes were mainly noted in the downstream portion of the basin. These variations then expanded to the middle and upper reaches. A precipitation–runoff double cumulative curve was used to detect the breakpoint of the precipitation–runoff relationship and to identify the impacts of human activities on runoff in the YR. Results show that the relatively uniform precipitation–runoff relationship has changed since 1993 in the upstream reaches and since 1970 in the middle and downstream reaches. Additionally, the relationship was more sensitive in the Lanzhou section. Human activities have become the dominant influencing factor on runoff variation since the 1970s. After the 1990s, the percentages of runoff variations due to human activities were 74.87%, 82.2%, 80.63%, and 88.71% at the Lanzhou, Toudaoguai, Huayuankou, and Lijin stations, respectively.


2012 ◽  
Vol 212-213 ◽  
pp. 108-112 ◽  
Author(s):  
Wen Sheng Dong ◽  
Xiu Fang Jiang ◽  
Xian Feng He ◽  
Ying Ying Zai

Aim to the high sandy river “ripping up the riverbed” phenomenon, by experiment, analyzing the relationship between clay dry density, water content, plasticity index and its shear strength, and its mechanical properties. Create the conditions for studying clay mechanical strength and the critical condition of “bottom tearing scour”.


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