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Tracing the provenance of aeolian loess in the Yangtze River Delta through zircon U–Pb age and geochemical investigations

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Journal of Mountain Science 2018年第4期15卷 708-721页

作者： QIAN Peng ZHENG Xiang-min CHENG Jun HAN Yu-jie DONG Yan ZHANG Jian-guo school of geography Nantong University Department of geography East China Normal University school of Geosciences University of South Florida

Given the conflicts over the proposed formation mechanisms of Xiashu loess, the question of the provenance of sediments comprising the Xiashu loess in the Yangtze River Delta has not been satisfactorily resolved. In this study, the provenance of aeolian sediments of the Yangtze River Delta, China was examined by applying the detrial zircon U–Pb dating technique, Sr–Nd isotopic and trace element compositional analysis. U-Pb dating analysis was conducted on the Xiashu loess at three locations over the Yangtze River Delta, including Huangnishan(HNS) hill, Shengshan(SS) island and the Xuancheng(XC) area. The Xiashu loess and the sediments of the Yangtze River Valley share considerable similarity in their zircon U-Pb age spectra with the same main age peak and comparable age distribution. By contrast, significant differences in the age spectra, existbetween the Xiashu loess and loess deposits of Chinese Loess Plateau(CLP). Coarse grains of the Yangtze River Delta loess may have a proximal material source identical to the sediments from the Yangtze River valley. Sr–Nd isotopic values of the Xiashu loess match those from the northern margin of the Tibetan Plateau. Rare earth element ratios independent of grain size illustrate that the values from loess of the Yangtze River Delta mostly overlap with those of CLP loess. This feature implies that loess from the Yangtze River Delta has a dominant source of distant material similar as the CLP loess. As such, we conclude that multi-proxy analysis of sediments can shed new light on tracing the provenance of aeolian loess in the Yangtze River Delta.

关键词： Aeolian loess Provenance tracing Zircon U-Pb age Geochemistry Yangtze River Delta

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Spatial Equity Evaluation of Rural Eldercare Service Resources Based on Accessibility: A Case Study of Huanxian County of Gansu Province, China

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Chinese Geographical Science 2024年第5期34卷 869-885页

作者： CHANG Xiaoyan MA Libang CUI Xijuan TAO Tianmin ZHAO Shoucun College of geography and Environmental Science Northwest Normal UniversityLanzhou 730000China Key Laboratory of Resource Environment and sustainable development of Oasis Gansu ProvinceLanzhou 730070China Northwest Institute of Urban-Rural development and Collaborative Governance Lanzhou 730070China

Safeguarding the elderly population in the countryside is an inherent requirement for alleviating social conflicts in rural areas and effectively carrying out China’s Rural *** existing spatial mismatch between rural elderly service facilities and pop-ulation distribution in China aggravates the imbalance of facility resource space,how to improve the accuracy of demand and supply results and better measuring the spatial fairness of elderly service is significant to realize the optimal allocation of rural elderly *** on the above,this study pays attention to the refined needs of the elderly population,and focuses on the spatial equity of the rural elderly facilities,to make up for the short boards of the basic public services in the countryside and realize the all-round rural *** study takes Huanxian County in the hilly loess area of Longdong,China as an example and explores the spatial equity of rural elderly services by using the Urban Spatial Network Analysis(UNA)to measure the accessible quantity and supply capacity of elderly *** results found that there were 553 rural eldercare service facilities in Huanxian County,including 285 eldercare facilities and 268 medical and health facilities,and the spatial distribution is characterized by a southward shift in the east and uneven regional ***,the supply capacity of rural pension services was generally good,with the township center as the gathering point and spreading out in a faceted manner,with nearby townships forming a contiguous area;however,there were strong contrasts and obvious differences in the strength of supply ***,the spatial equity of rural eldercare service was *** 42.05%of the eld-erly population grid cells,eldercare service spatial equity was extremely *** spatial distribution also presented a northern preference over the southern,a western preference over the eastern,and a concentration along the *** stud

关键词： rural eldercare service spatial equity hilly loess region of Longdong Huanxian County China

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Advancing the Disaster and development Paradigm

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International Journal of Disaster Risk Science 2018年第4期9卷 486-495页

作者： Andrew E.Collins Department of geography and Environmental Sciences /Disaster and development Network (DDN) Northumbria University

Consolidation of disaster and development studies as an integrated field of action research that influences policy has proved to be fundamental to global disaster risk reduction, sustainable development, climate change, and humanitarian agreements. However, challenges in achieving targets, such as those of the Sendai Framework for Disaster Risk Reduction 2015–2030 and the sustainable development Goals, requires further advances of the disaster and development paradigm underpinning these aspirations. This article presents perspectives that grew primarily from local action research, particularly research carried out with marginalized and highly at-risk groups of people in Southern Africa and South *** fronts from these findings emphasize disaster and development risk assessment opportunities that consolidate earlier ideas and extend understanding of disaster and development-related risk intervention options. These acknowledge severe shortcomings in disaster risk reduction progress while including greater use of hope as an active ingredient. This process of paradigm exploration remains fundamental to achieving disaster risk reduction, sustainable development, and associated policy objectives. The analysis presented here reiterates earlier groundings in people-centric perspectives, emphasizing social relations and systems of meaning as essential active ingredients for challenging power structures, technology, education, and human behavior. The analysis proposes some consequent thematic fronts for increased investment. These includeinvesting in early buildup of well-being before a disaster,better living with uncertainty, and overcoming the barriers to desired disaster and development outcomes. The article is intended to contribute to an ever-evolving paradigm of disaster and development risk that requires impetus from personal and collective values beyond calculations of disaster and development.

关键词： Disaster and development paradigm Disaster risk reduction Disaster risk management Local action research

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How Chinese Financial Centers Integrate into Global Financial Center Networks:An Empirical Study Based on Overseas Expansion of Chinese Financial Service Firms

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Chinese Geographical Science 2018年第2期28卷 217-230页

作者： PAN Fenghua HE Ziyun Thomas SIGLER Kirsten MARTINUS Ben DERUDDER school of geography Faculty of Geographical Science Beijing Normal University school of geography Planning and Environmental Management University of Queensland school of Earth and Environment University of Western Australia Department of geography Ghent University

The increasing globalization of the Chinese economy has been enabled by both Chinese financial institutions operating globally as well as international firms operating within China. In geographical terms, this has been organized through a number of strategic cities serving as gateways for the exchange of financial functions, products and practices between China and the global economy. Drawing on location data of financial service firms in China listed on stock exchanges in Shenzhen, Shanghai and Hong Kong, this paper shows that Chinese financial firms are expanding globally and how Chinese financial centers are positioned and connected in the urban networks shaped by these financial service firms. It is found that Hong Kong, China, holds strategic positions in the integration of Chinese cities into global financial center networks, and that establishing a foothold in global financial centers such as New York and London has been a priority for Chinese financial institutions. The increasing capital flows directed by Chinese financial institutionssuggests a shifting global financial geography, with numerous Chinese cities playing increasingly important roles within global financial center networks.

关键词： urban networks corporate networks financial service firms global financial centers China

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Empirical Research on Carrying Capacity of Human Settlement System in Dalian City, Liaoning Province, China

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Chinese Geographical Science 2015年第2期25卷 237-249页

作者： ZHENG Defeng ZHANG Yu ZANG Zheng SUN Caizhi school of Urban Planning and Environmental Science Liaoning Normal University Center for Studies of Marine Economy and sustainable development Liaoning Normal University

Using the theories of population carrying capacity and ecological elasticity in other fields for reference, the connotation of regional human settlement system was defined from the viewpoint of the complex relationship among the factors such as regional population, resources, environment and economic and social development in the context of China′s rapid urbanization. Then the concept and characterization methods of the regional human settlement carrying capacity were proposed by means of population scale. Furthermore, a model of carrying capacity-pressure-state-response(CPSR) on regional human settlement system was established by referencing pressure-state-response(PSR) model, and the Catastrophe Theory was introduced to determine the corresponding standards of multi-criteria programming and evaluation. Taking Dalian City, Liaoning Province, China as an example, an empirical analysis on evaluation of human settlement system from 2000 to 2012 was carried out. The results showed that the carrying capacity of human settlement system in Dalian was fluctuating between 9.6 × 106 to 10 × 106 persons with a quantitative stage of the dynamic regulation. During the research period the load index of human settlement system in Dalian dropped from 0.96 to 0.84 with a lower pressure of human settlement system than the national average level. And the emergency response grades of human settlement system in Dalian were kept in grade Ⅱ(orange warning) or grade Ⅲ(yellow warning). Human settlement system of Dalian was in slight security state as a whole, but the load had a tendency of increase in recent years. The related departments should pay close attention to regional human settlement system and take active measures to improve human settlement by both intensity control and total quantity control. By comparison, analysis and discussion, it was considered that the results were basically accordded with the current situations of human settlement in Dalian, and the evaluation results w

关键词： human settlement capacity-pressure-state-response(CPSR) model carrying capacity multi-objective decision making Dalian City China

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Response of nephelometric turbidity to hydrodynamic particle size of fine suspended sediment

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International Journal of Sediment Research 2020年第5期35卷 444-454页

作者： Christina Bright Sarah Mager Sophie Horton school of geography University of Otago

Turbidity is used as a surrogate for suspended sediment concentration(SSC),and as a regulatory tool for indicating land use disturbance and environmental *** relates linearly to suspended material,however,can show non-linear responses to particulate organic matter(POM),concomitant with changes in particle size distribution(PSD).In the paper the influence of ultra-fine particulate matter(UFPM) on specific turbidity and its association with POM in suspended sediment are shown for alpine rivers in the Southern Alps of New *** approach was two-fold:a field-based investigation of the relations between SSC,POM,and turbidity sampled during event flow;and experimental work on hydrodynamic particle size effects on SSC POM,PSD,and *** turbidity changes over event flow and are sensitive to increasing proportional amounts of sand,UFPM,and POM in ***,the UFPM is the size fraction(<6 μm) where POM *** implications of the current study are that the slopes of turbidity-SSC relations are undesirable in locations that may be dominated by cyclic release of POM or distinct pulses of fine-grained *** locations where the turbidity-SSC slopes approximate 2,the POM proportion is usually <10% of the total suspended ***,when turbidity-SSC slopes are <1 this is likely caused by high amounts of side-scatter from UFPM concomitant with higher proportions of ***,the use of turbidity as a proxy for determining SSC may have serious consequences for the measurement of representative suspended sediment data,particularly in locations where POM may be a significant contributor to overall suspended load.

关键词： Turbidity Nephelometry Suspended sediment concentration Particle size distribution Particulate organic matter

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Assessing OSM building completeness for almost 13,000 cities globally

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International Journal of Digital Earth 2022年第1期15卷 2400-2421页

作者： Qi Zhou Yuheng Zhang Ke Chang Maria Antonia Brovelli school of geography and Information Engineering China University of GeosciencesWuhanPeople’s Republic of China International Research Center of Big Data for sustainable development Goals BeijingPeople’s Republic of China Department of Civil and Environmental Engineering Politecnico di MilanoMilanoItaly

OpenStreetMap(OSM)is an essential source for acquiring building data,although such data may suffer from quality *** studies have focused on assessing OSM building data quality but few have been carried out on a global *** study aims to assess OSM building completeness(a quality measure)for 12,975 cities across the *** was achieved by employing population grid data as a proxy for reference building *** only the completeness of each city but also that of the grids within that city was *** assessment results were evaluated based on calculating the overall accuracy and the r-square value between estimated and reference OSM building completeness *** showed that for 75%of cities,the completeness is lower than 20%;no more than 9%of cities have an estimated completeness higher than 80%.The overall accuracies of most countries were higher than 80%.The estimated completeness was also highly correlated with the reference completeness,which verifies the effectiveness of our *** results may be useful for acquiring and updating building data in OSM.A global and open dataset related to OSM building completeness has been made available for public use.

关键词： OpenStreetMap building data data quality population data WorldPop

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Rating crowdsourced annotations: evaluating contributions of variable quality and completeness

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International Journal of Digital Earth 2014年第8期7卷 650-670页

作者： Giles M.Foody school of geography University of NottinghamNottinghamUK

Crowdsourcing has become a popular means to acquire data about the Earth and its environment inexpensively,but the data-sets obtained are typically imperfect and of unknown *** common imperfections with crowdsourced data are the contributions from cheats or spammers and missing *** effect of the latter two imperfections on a method to evaluate the accuracy of crowdsourced data via a latent class model was *** simulated and real data-sets,it was shown that the method is able to derive useful information on the accuracy of crowdsourced data even when the degree of imperfection was very *** practical potential of this ability to obtain accuracy information within the geospatial sciences and the realm of Digital Earth applications was indicated with reference to an evaluation of building damage maps produced by multiple bodies after the 2010 earthquake in ***,the method allowed data-sets to be ranked in approximately the correct order of accuracy and this could help ensure that the most appropriate data-sets are used.

关键词： volunteered geographic information accuracy error

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Quantifying spatial scale of positive and negative terrains pattern at watershed-scale:Case in soil and water conservation region on Loess Plateau

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Journal of Mountain Science 2017年第8期14卷 1642-1654页

作者： YANG Feng ZHOU Yi school of geography and Tourism Shaanxi Normal University

The positive and negative terrains(P-N terrains) widely distributed across China's Loess Plateau constitute the dual structure characteristic of loess landforms. Analysis of loess P-N terrains at the watershed scale can serve to elucidate the structural characteristics and spatial patterns of P-N terrains, which benefits a better understanding of watershed evolution and suitable scales for loess landform research. The Two-Term Local Quadrat Variance Analysis(TTLQV) is calculated as the average of the square of the difference between the block totals of all possible adjacent pairs of block size, which can be used to detect both the scale and the intensity of landscape patches(e.g., plant/animal communities and gully networks). In this study, we determined the latitudinal and longitudinal spatial scale of P-N terrain patterns within 104 uniformly distributed watersheds in our target soil and water conservation region. The results showed that TTLQV is very effective for examining the scale of P-N terrain patterns. There were apparently three types of P-N terrain pattern in latitudinal direction(i.e., Loess Tableland type, Loess Hill type, and Transitional Form between Sand and Loess type), whereas there were both lower and higher values for P-N terrain pattern scales in all loess landforms in the longitudinal direction. The P-N terrain pattern alsoclearly presented anisotropy, suggesting that gully networks in the main direction were well-developed while others were relatively undeveloped. In addition, the relationships between the first scales and controlling factors(i.e., gully density, nibble degree, watershed area, mean watershed slope, NDVI, precipitation, loess thickness, and loess landforms) revealed that the first scales are primarily controlled by watershed area and loess landforms. This may indicate that the current spatial pattern of P-N terrains is characterized by internal force. In selecting suitable study areas in China' Loess Plateau, it is crucial to u

关键词： Positive and negative terrains TTLQV Spatial pattern scale Loess landforms Loess Plateau

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Non-coordination in China′s Urbanization: Assessment and Affecting Factors

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Chinese Geographical Science 2013年第6期23卷 729-739页

作者： SUN Pingjun SONG Wei XIU Chunliang LIANG Zhenming school of geography Sciences Northeast Normal University Department of geography and Geo-sciences University of Louisville

Urbanization is a comprehensive concept, a trinity process that population urbanization, economic urbanization and space urbanization, is based on the interactions and mutual influences among the in which, people are the central and leading players in this process, while economic activities serve as the driving force and space is the carrier-the physical or material setting as well as the product. So the coordination among these processes is crucial for a country or region＇s sustainable development. China is experiencing rapid growth of cities and a surge in urban population, with the basic national condition of many people and little land, which calls for a systematic study of the issue of coordinated urbanization from theoretical, methodological and practical perspectives. Based on the concept of urbanization and non-coordination of urbanization, this article built a quantitative method to identify and evaluate the urbanization and non-coordination of urbanization, and made an empirical analysis in China between 2000 and 2008. The results show that the non-coordination overall level of China＇s urbanization declined during the study period, because population urbanization, economic urbanization, and space urbanization exhibited different trajectories of change. This study also reveals that performance assessment system, household registration system, and urban land expropriation system, etc., are the main affecting factors. At the end, we put forward some suggestions to achieve sustainable development of China＇s urbanization from the aspects of improving the local government＇s obiective function, imolementing the urban plalming svstem, enforcing public particination asnects and so on.

关键词： non-coordination of urbanization coordinated development degree China

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