The Characteristics and Causes of Land Subsidence in Tanggu Based on the GPS Survey System and Numerical Simulation

Land subsidence is a severe hazard threatening Tanggu, a flat lowland area, and evidences of land subsidence can be seen throughout the city. A new reasonable GPS network was set up in this area from 2008 to 2010. The monitoring data show that land subsidence was serious and two main subsidence cones were obviously formed in the region. One emerged at Hujiayuan, with the maximum rate reaching 60 mm/a, and the influence region enlarged prominently from 2005 to 2010. The other one occurred at Kaifaqu, which became obvious only after 2005, and it showed a decreasing tendency with time. To analyze the causes of ground settlement, a correlation between groundwater withdrawal and land subsidence was firstly made. The results confirmed that over-exploitation of groundwater was the major cause for the severe settlement in Hujiayuan. Meanwhile, the subsidence of Kaifaqu was also related to groundwater withdrawal before 2005. However, the relationship became unconspicuous after 2005. To find the cause of this abnormity, a three-dimensional finite element numerical model, coupled with groundwater flow and subsidence, was built. The simulation results indicate that the subsidence induced by high-rise buildings is serious, but the affected range is limited and it also shows a decreasing trend with time, corresponding to the subsidence characteristics at Kaifaqu. Therefore, more attention should be paid to this hazard induced by engineering construction besides groundwater withdrawal, as more high-rise buildings are under construction in Tanggu.     

Peaked abundance of Calanus sinicus earlier shifted in the Changjiang River (Yangtze River) Estuary: a comparable study between 1959, 2002 and 2005

The sea surface temperature (SST) of the East China Sea (ECS) increased in the past decades,which may have a great impact on the ecosystem of the ECS,including the changes in plankton-population structure.In this paper,the changes in peaked abundance of Calanus sinicus in the Changjiang River (Yangtze River) Estuary were compared between 1959 and 2002,based on the data collected from the seasonally oceanographic cruises and those performed in spring of 2005.It was much higher in spring compared with that in other seasons both in 1959 and 2002.Furthermore,in spring 2005,the time for occurrence and decrease of the peaked C.sinicus abundance advanced about one month, accompanying the increase in the sea surface water temperature (SST).It peaked in June and decreased in July in 1959,however,in 2005,it peaked in May and attenuated sharply in early June.The earlier decrease of peaked C.sinicus abundance may further deteriorate the ecosystem in the Changjiang River Estuary and north nearshore of the ECS.     

Multistage Deformation in the Northeastern Segment of the Jiangshao Fault (Suture) Belt: Constraints for the Relationship between the Yangtze Plate and the Cathaysia Old Land

Multistage deformation events have occurred in the northeastern Jiangshao Fault (Suture) Belt. The earliest two are ductile deformation events. The first is the ca. 820 Ma top-to-the-northwest ductile thrusting, which directly resulted from the collision between the Cathaysia Old Land and the Chencai Arc (?) during the Late Neoproterozoic, and the Jiangnan Orogenic Belt that formed as the ocean closed between the Yangtze Plate and the jointed Cathaysia Old Land and the Chencai Arc due to continuous compression. The second is the ductile left-lateral strike-slipping that occurred in the latest Early Paleozoic. Since the Jinning period, all deformation events represent the reactivation or inversion of intraplate structures due to the collisions between the North China and Yangtze plates during the Triassic and between the Philippine Sea and Eurasian plates during the Cenozoic. In the Triassic, brittle right-lateral strike-slipping and subsequent top-to-the south thrusting occurred along the whole northeastern Jiangshao Fault Zone because of the collision between the North China and Yangtze plates. In the Late Mesozoic, regional extension took place across southeastern China. In the Cenozoic, the collision between the Philippine Sea and Eurasian plates resulted in brittle thrusts along the whole Jiangnan Old land in the Miocene. The Jiangshao Fault Belt is a weak zone in the crust with long history, and its reactivation is one of important characteristics of the deformation in South China; however, late-stage deformation events did not occur beyond the Jiangnan Old Land and most of them are parallel to the strike of the Old Land, which is similar to the Cenozoic deformation in Central Asia. In addition, the Jiangnan old Land is not a collisional boundary between the Yangtze Plate and Cathaysia Old Land in the Triassic.     

Investigating the presence of organochlorine pesticides and polychlorinated biphenyls in wild and farmed gilthead sea bream (Sparus aurata) from the Western Mediterranean sea

The presence of organochlorine pesticides and polychlorinated biphenyls in wild and farmed gilthead sea bream (Sparus aurata) from the Western Mediterranean, Spain, is investigated. These pollutants were determined in white and red muscle and liver by gas chromatography coupled to tandem mass spectrometry. Contaminant profiles present in both wild and farmed fish tissues include DDTs, PCBs and HCB. The highest concentrations of contaminants were found in liver, and an increase in pollutant levels was observed in autumn, before spawning. This fact is explained in light of increased food intake when sea water temperatures increase. Gilthead sea bream from Western Mediterranean populations showed significantly higher concentrations of DDTs and PCBs than farmed fish from the same area. This fact is attributed to the low level of organochlorine contaminants present in fish feed supplied to the cultured fish. The diet is highlighted as an important factor in understanding differences observed in organochlorine pollutants levels of fish tissues.     

Land cover change and its response to water level around Tonle Sap Lake in 1988–2020

The transboundary influence of environmental change is a critical issue in the Lancang-Mekong region. As the largest river-connected lake in the lower Mekong, the ecological change and influence of Tonle Sap Lake have received widespread attention and discussion, especially after 2008, when the hydrological regime of the Lancang-Mekong River mainstream underwent distinct changes. However, the linkage and coupling mechanism between the lake riparian environment and mainstream water level change a...     

A discussion on the distribution of international container junction ports in northern China

1 The Raising of the Problem 1.1 The development of the international container traffic At the end of the 1930s, the developed countries began to develop container traffic, following the first one established on land which prevailed marine transport after expansion in the 1970s and the 1980s. Then many junction ports had special container berths constructed throughout the world and all main transportation lines were containerized. With the development of the world trade and increase of the pr…     

Urbanization under globalization: How does the Belt and Road Initiative affect urbanization levels in participating countries

China’s Belt and Road Initiative(BRI) presents the world with a new era of inclusive globalization, which will shape urbanization patterns globally. This study considered the launch of BRI as a quasi-experiment, where we evaluated the BRI’s impact on urbanization by way of difference-in-differences(DID) and propensity score matching(PSM) methods. The results showed that the BRI exerted a significantly negative effect on urbanization in its first three years. Its positive effect emerged from the ...     

Urban Construction Land Suitability Evaluation Based on Improved Multi-criteria Evaluation Based on GIS （MCE-GIS）： Case of New Hefei City,China

Urban construction land suitability evaluation （UCLSE） is a complex system engineering and the basis for rational use of the limited urban land resources in China. It has an important practical value on urban construction land use planning and management from the angle of methodology. As a widely used technique, traditional multi-criteria evaluation based on GIS （MCE-GIS）, is not suitable for UCLSE. This study develops an improved MCE-GIS method which could be more suitable for UCLSE based on urban complex ecological system theory and the summary of the shortcomings of traditional MCE-GIS. The improvements include three aspects： a composite evaluation index system rather than natural indexes alone, an index weight calculated by using fuzzy Analytic Hierarchy Process （AHP） method rather than the common AHP method, and the integrated overlay rule, which includes selecting the minimum value, weighted linear combination （WLC） and simple summation. The main advantage of this improved technique is that it can make UCLSE more comprehensive, more operational and more reasonable. It can provide a scientific basis for decision making in the planning and management of urban construction land use. The improved MCE-GIS system has been adopted in the New Hefei City, Anhui Province, China. Based on the results of UCLSE in New Hefei, three functional areas including construction-appropriate areas, construction-restricted areas and construction-forbidden areas could be worked out, in which 36.90% of the total study area could be developed as urban construction land and the remaining 63.10% should be protected as reserves land or as ecological land. Furthermore, the results can orovide scientific decision suooort for spatial planning and eco-environment nrotection in New Hefei.