Quantitative Study on Characteristics of Hydrological Drought in Arid Area of Northwest China Under Changing Environment

2021 ◽  
pp. 126343
Author(s):  
Peng Yang ◽  
Jun Xia ◽  
Yongyong Zhang ◽  
Chesheng Zhan ◽  
Wei Cai ◽  
...  
2015 ◽  
Vol 52 (2) ◽  
pp. 123-129 ◽  
Author(s):  
Y. B. Liu ◽  
L. L. Zhang ◽  
Q. Z. Liu

Summary Nematode communities in the soils of wheat (Triticum aestivum Linn.) rhizosphere grown alone and grown in jujube (Ziziphus jujuba Mill.) orchard were investigated for three years in Hetian arid area, Xingjiang Uygur Autonomous Region, northwest of China. The results showed that eu-dominant families were Rhabditidae, Cephalobidae and Aphelenchidae among 15 families and 19 genera. Nematode abundance in wheat rhizosphere soil was smaller in wheat/jujube intercropping system, mainly because of lower numbers of bacterial feeders and fungal feeders. Besides, the nematode numbers of cp-1 and cp-2 (cp, colonizer-persister) guilds were significantly lower in wheat/jujube intercropping system than that in monoculture wheat system, due to the markedly lower numbers of Rhabditidae and Cephalobidae, although those of cp-3 and cp-4 guilds had no significant differences between monoculture and intercropping systems. Shannon-Weaver index (H’), genus dominance index (Ig) and structural index (SI), represented soil food web diversity and structure, had no differences between monoculture and intercropping systems. Significantly lower values of Wasilewska index (WI) and PPI/MI in monoculture wheat than in intercropping system. It was concluded that the soil status in monoculture wheat system exhibited better soil ecosystem in compared with wheat/ jujube intercropping system.


2014 ◽  
Vol 1065-1069 ◽  
pp. 2942-2947
Author(s):  
Mei Wang ◽  
De Shan Tang ◽  
Wei Shan Hu ◽  
Yi Fan Bai

Human-water relationship evaluation method based on cloud model is put forward to cope with the vagueness in evaluation language. With the intensive study of the specialty in human-water relationship in Northwest China arid area, three dimensions related to human-water relationship, natural water cycle’s health degree (NWHD), Social water cycle’s rationality degree (SWRD) and human-to-water fitness degree (HWFD) are selected to describe the harmony degree between water system and human system. The limit of evaluation index subordinate to each dimension corresponding to every harmony level is determined, and thus we can generate a comprehensive cloud model with evaluation index harmony level. When numeric values substitute for basic evaluation indexes, combined with the weights calculated from entropy weight method and AHP method, we get the certainty distributions of dimension indexes and integration objects among each harmony level. Case shows that human-water relationship evaluation method based on cloud model can effectively solve the vagueness and uncertainty in evaluation language. The evaluation results reflect the harmony degree in Northwest China arid area precisely.


1995 ◽  
Vol 73 (6) ◽  
pp. 1269-1284 ◽  
Author(s):  
Yasushi Mitsuta ◽  
Taiichi Hayashi ◽  
Tetsuya Takemi ◽  
Yinqiao Hu ◽  
Jiemin Wang ◽  
...  
Keyword(s):  

Water ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 644 ◽  
Author(s):  
Xin Wang ◽  
Kebin Shi ◽  
Quan Shi ◽  
Hanwei Dong ◽  
Ming Chen

Tunnel water inrush is complex, fuzzy, and random, and it is affected by many factors, such as hydrology, geology, and construction. However, few papers have considered the impact of dynamic monitoring on water inrush in previous research. In this study, considering geological, hydrological, and construction factors, as well as dynamic monitoring, a new multi-index evaluation method is proposed to analyze the risk of tunnel water inrush based on the normal cloud model. A new weight algorithm combining analytic hierarchy process and entropy method is used to calculate the index weight. The certainty degree of each evaluation index belonging to the corresponding cloud can be obtained by the cloud model theory. The final level of tunnel water inrush is determined via the synthetic certainty degree. The proposed method is applied to analyze the risk of water inrush in the SS (Shuang-san) tunnel constructed by a tunnel boring machine in the arid area of Northwest China. The evaluation results are not only basically identical to the results calculated by the ideal point and gray relation projection methods, but also agree well with the actual excavation results. This demonstrates that this new risk assessment method of water inrush has high accuracy and feasibility. Simultaneously, it also provides a new research idea to analyze the probability of tunnel water inrush and can provide a reference for related projects.


Sign in / Sign up

Export Citation Format

Share Document