scholarly journals Basic Mechanical Parameter Relations of Soft Clay in Pearl River Delta

2014 ◽  
Vol 8 (1) ◽  
pp. 320-325 ◽  
Author(s):  
Zhangming Li ◽  
Na Qi ◽  
Zhibin Masumi ◽  
Weidi Lin

Basic parameters relations among CPT parameters, un-drained strength and other mechanical parameters of soft clay are presented based on an elastic-plastic solution for cylindrical cavity expansion for soil investigation in energy engineering. The relation between CPT parameters and shear strength from vane test is also presented based on the result. Thus, the CPT parameters can be determined directly by elastic parameters and shear strength or vane shear parameters and vice versa. That makes it possible to save the high test costs and provide theoretical formulas to avoid some tests which are limited due to the site and/or other condition. Results are compared between the relations and in situ data at a large-scale project in the Pearl River Delta. The results showed consistency between the relation and in situ data.

Author(s):  
Xiangbo Feng ◽  
Wei Zhang ◽  
Zhenglei Zhu ◽  
Amulya Chevuturi ◽  
Wenlong Chen

AbstractUnderstanding water level (WL) fluctuations in river deltas is of importance for managing water resources and minimizing the impacts of floods and droughts. Here, we demonstrate the competing effects of atmospheric and oceanic forcing on multi-timescale variability and changes in the Pearl River Delta (PRD) WLs in southern China, using 52 years (1961–2012) of in-situ observations at 13 hydrological stations. PRD WL presents significant seasonal to decadal variations, with large amplitudes upstream related to strong variability of southern China rainfall, and with relatively small amplitudes at the coastal stations determined by sea level (SL) fluctuations of the northern South China Sea. We find that the strengths of atmospheric and oceanic forcing in PRD are not mutually independent, leading to a distinct contrast of WL–forcing relationships at upstream and coastal stations. In the transition zone, because of counteracts of atmospheric and oceanic forcing, no robust relationships are identified between WL and either of the forcing. We further show that in the drought season of the warm ENSO and PDO epochs, the effect of atmospheric (oceanic) forcing on PRD WL is largely enhanced (weakened), due to increased southern China rainfall and negative SL anomalies. Over the observation period, WL significantly decreased at upstream stations, by up to 28–42 mm/year for flood season, contrasting with the upward trends of <4.3 mm/year at coastal stations across all seasons. Southern China rainfall explains little of the observed WL trends, whilst SL rise is mostly responsible for the WL trends at coastal stations.


2010 ◽  
Vol 10 (5) ◽  
pp. 2079-2089 ◽  
Author(s):  
X. Li ◽  
T. Brauers ◽  
M. Shao ◽  
R. M. Garland ◽  
T. Wagner ◽  
...  

Abstract. We performed MAX-DOAS measurements during the PRiDe-PRD2006 campaign in the Pearl River Delta region 50 km north of Guangzhou, China, for 4 weeks in June 2006. We used an instrument sampling at 7 different elevation angles between 3° and 90°. During 9 cloud-free days, differential slant column densities (DSCDs) of O4 (O2 dimer) absorptions between 351 nm and 389 nm were evaluated for 6 elevation angles. Here, we show that radiative transfer modeling of the DSCDS can be used to retrieve the aerosol extinction and the height of the boundary layer. A comparison of the aerosol extinction with simultaneously recorded, ground based nephelometer data shows excellent agreement.


2016 ◽  
Vol 121 (15) ◽  
pp. 9105-9116 ◽  
Author(s):  
Xinhui Bi ◽  
Qinhao Lin ◽  
Long Peng ◽  
Guohua Zhang ◽  
Xinming Wang ◽  
...  

Land ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 1357
Author(s):  
Yingxian Deng ◽  
Ren Yang

Referencing the land use classification system of the “production-living-ecological” space and using 1 km × 1 km grids, this study examines the spatial pattern changes of “production-living-ecological” space in Guangdong Province, China, from 1990 to 2017. In the study, a multiple linear regression analysis model was constructed to explore the influencing factors and attribution mechanism of the changes. The results showed that between 1990 and 2017, the production spaces were mainly distributed in the Pearl River Delta and other coastal areas, showing a slight expansion trend (1). The expansion of production spaces mainly gathered in the Pearl River Delta, while the reduction was characterized by point-type dispersed. Living spaces were mainly distributed in the Pearl River Delta, the Shantou–Shanwei–Chaozhou–Jieyang urban agglomeration, the Zhanjiang-Maoming–Yangjiang urban agglomeration, and other rapidly growing urbanized areas. They showed a spatial pattern of “large scale agglomeration and small scale dispersion” with a trend towards expansion. Living spaces in urban agglomerations such as the Pearl River Delta showed a large-scale expansion from the core to the peripheral area, while expansion in other areas was small-scale and point-type. The reduction of living spaces was point-type dispersed. The ecological spaces were mainly distributed in mountainous and hilly areas in eastern, western, and northern Guangdong and showed a “regional agglomeration and partially fragmented” spatial pattern. Ecological spaces in urban agglomerations showed large-scale and regional reductions, while reductions in other areas were small-scale and point-type. Ecological space expansions were point-type dispersed. Human, natural, and especially land-use type factors drove the changes of Guangdong’s production-living-ecological spaces (2). The changes of the production-living-ecological space pattern resulted from the interaction between human society, nature, and politics (3).


2010 ◽  
Vol 29 (6) ◽  
pp. 35-42
Author(s):  
Jianhua WANG ◽  
Linglong CAO ◽  
Xiaojing WANG ◽  
Xiaoqiang YANG ◽  
Jie YANG ◽  
...  

Wetlands ◽  
2021 ◽  
Vol 41 (4) ◽  
Author(s):  
Xiao-Shan Fang ◽  
Shuang Liu ◽  
Wei-Zhi Chen ◽  
Ren-Zhi Wu

AbstractThe Guangdong Xinhui National Wetland Park (GXNWP) in the Pearl River Delta is an important stopover for migratory birds in China and East Asia. Due to high levels of interference, high sensitivity and fragile environmental constraints, an efficient method to assess the health status of wetland parks such as the GXNWP is urgently needed for sustainable development. In this study, we proposed a habitat-landscape-service (HLS) conceptual model that can be used at the site scale to evaluate health status in terms of habitats, landscapes and services by considering the complex ecosystem of wetland parks. This HLS model included 28 evaluation indicators, and the indicator weights and health-grade divisions were based on expert scores using both the analytic hierarchy process (AHP) and fuzzy comprehension evaluation (FCE) methods. The results showed that the health status of the GXNWP was at the “subhealthy” level, with a membership function of 0.4643. This study found that habitat indicators (0.5715) were the key factors affecting the GXNWP health status, followed by service indicators (0.2856) and landscape indicators (0.1429). The HLS-AHP-FCE method provides a holistic health evaluation indicator system and diagnostic approach for rapidly developing wetland parks in the Pearl River Delta, China.


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