Xiamen City Research Articles

Assessing the adaptive capacity of urban form to climate stress: a case study on an urban heat island

Urban land planning shapes the urban form and is considered to be one of the many tools important for climate adaptation. Yet there is little knowledge about the adaptive capacity of urban forms to climate stress, or of an appropriate assessment method. Through a case study on the urban heat island (UHI) in Xiamen City, China, we propose a novel approach that integrates several aspects to assess the adaptive capacity of urban form to climate stress. These aspects include the calculation of urban form, the determination of climate stress and land use modeling. Our results demonstrate that this approach is applicable for assessing the adaptive capacity of urban form in the historical, current and future multitime scales. Both urban planning aspects (e.g. population density, land use mix, road density and percentage of green open space) and landscape features (e.g. shape complexity, contiguity and compactness) are found to be key urban form drivers affecting UHI. The adaptive capacity of the urban form to UHI in Xiamen City has been declining dramatically, and is expected to continue to decline in the future as long as adaptation continues to not be integrated in urban land use planning. Our analysis suggests that urban managers need to review the past development model of land use and rethink the current approach to urban planning: most urgent is the need to take full account of adaptation in future land use planning and implementation, so as to enhance climate resilience.

Distribution and source appointment of rare earth elements in offshore sediments of Western Xiamen Bay, Southeast China

The REEs concentrations in offshore sediments (surface sediments and core sediments) of Western Xiamen Bay and some potential sources (parent materials, Pb-Zn deposit, vehicle exhaust, atmospheric dust, ship paint, coal combustion and domestic sewage sludge) were determined to investigate the geochemical characteristics and major sources of REEs in the sediments of Western Xiamen Bay. The results showed that the mean concentrations of REEs in surface sediments and core sediments were 245.9 mg·kg−1 and 220.0 mg·kg−1, respectively, which were close to the background value of topsoil in Xiamen City. There were negative Eu anomaly and no Ce anomaly in general and LREEs had a significant enrichment relative to HREEs. The results of enrichment factor showed that REEs were slightly enriched in surface sediments. The patterns of chondrite-normalized REE exhibited a negative slope, indicating that the REEs in surface sediments were mainly from the continental crust. Parameters and normalized patterns of REEs suggested that the sediments in Western Xiamen Bay were mainly from terrestrial sources and also affected by anthropogenic activities such as domestic sewage sludge and coal combustion. The results of Pearson's correlations, chondrite-normalized REEs distribution patterns and ternary plot of (La/Yb)N-(La/Sm)N-(Gd/Yb)N for the surface sediments and some potential sources indicated that the REEs accumulated in the surface sediments might be related to natural sources (parent materials and Pb-Zn deposit) and anthropogenic activities (coal combustion and domestic sewage sludge).

Removal Efficiencies and Mechanism Research on Four Sulfonamides and Their Acetyl Metabolites in a Wastewater Treatment Plant

Acetyl metabolites are the major metabolites of sulfonamides. In order to investigate the removal mechanism of four commonly used sulfonamides and their metabolites in wastewater treatment plants, sulfonamides and their corresponding acetyl metabolites in wastewater and sludge in a wastewater treatment plant equipped with A2/O in Xiamen City were sampled. Sample selection was based on the hydraulic retention time. Solid phase extraction followed by high performance liquid chromatography tandem mass spectrometry (HPLC-MS/MS) was applied to analyze the target compounds. Results showed that six out of eight of the target compounds were detected in the wastewater, while five were detected in the sludge. Based on the removal efficiencies overall and of the different compartments, the concentration of sulfamethazine was almost unchanged during wastewater treatment plant (WWTP) processes, the other sulfonamides were removed with different removal efficiencies. Removal efficiencies varied for every compartment. The potential removal pathways were analyzed based on the mass balance of the target compounds. The removal pathway of sulfamethazine was sludge adsorption, while the potential removal mechanism of sulfamerazine, sulfadiazine, and sulfamethoxazole was biodegradation.

Predicting duration of traffic accidents based on cost-sensitive Bayesian network and weighted K-nearest neighbor

With the development of urbanization, road congestion has become increasingly serious, and an important cause is the traffic accidents. In this article, we aim to predict the duration of traffic accidents given a set of historical records and the feature of the new accident, which can be collected from the vehicle sensors, in order to help guide the congestion and restore the road. Existing work on predicting the duration of accidents seldom consider the imbalance of samples, the interaction of attributes, and the cost-sensitive problem sufficiently. Therefore, in this article, we propose a two-level model, which consists of a cost-sensitive Bayesian network and a weighted K-nearest neighbor model, to predict the duration of accidents. After data preprocessing and variance analysis on the traffic accident data of Xiamen City in 2015, the model uses some important discrete attributes for classification, and then utilizes the remaining attributes for K-nearest neighbor regression prediction. The experiment results show that our proposed approach to predicting the duration of accidents achieves higher accuracy compared with classical models.

Spatial and seasonal variation of the airborne microbiome in a rapidly developing city of China

Exposure to airborne microbes (AM) can affect the human microbiome and has various consequences for human health. Investigating the profiles of AM and the potential bacterial pathogens within, along with the factors influencing their community, is pivotal for understanding the impact of AM on human health. In this study, we collected AM during spring and summer from 11 sites with various levels of urbanization in the city of Xiamen, China. Bacterial community compositions of the AM were determined based on 16S rRNA gene amplicon sequencing. Firmicutes and Proteobacteria were the predominating phyla in the airborne bacterial communities, and a higher (P < 0.05) diversity of AM was found during the summer as compared to the spring. Significant differences in the community structure of the AM and the potential bacterial pathogens within airborne microbes were observed among the seasons and the sites with different levels of urbanization. Increases and/or decreases in the abundance of Bacillus and Acinetobacter could explain a major part of the variations in the AM community compositions. The proportion of potential bacterial pathogens during the summer was significantly higher (P < 0.01) than in the spring, and the relative abundance of several bacterial pathogens (i.e. Burkholderia multivoran, Enterococcus faecium and Streptococcus thermophilus) related to human diseases (39.8% of total pathogens on average) increased with increasing urbanization levels, suggesting that urbanization can increase the AM-associated human health risk.

Discussion on manufacturing technology of steel box girder of cross-line bridge engineering in Xiamen Hele road

Taking cross-line bridge road engineering of Jimei district Hele road (Jinting north road -Jimei north road section) of Xiamen city as the background, the paper introduces the overall segmentation and hoisting sequence scheme of steel box girder, the division of plate element, the setting method of jig-frame, the production process of steel box girder, the beam section of steel box girder and the overall welding process. And then it analyzes the geometric dimension accuracy control of element, the penetration control of U-rib weld on the plate element and the quality control features of diaphragm plate, solves the preassembly line shape of steel box girder and the precision of the interface matching connection and other difficult manufacturing problems. It ensures the smooth progress of the project, and provides a reference for manufacture of the steel box girder of similar projects.

Off-label use of tamoxifen in a Chinese tertiary care hospital.

Background Tamoxifen is an estrogen receptor modulator used for the treatment of breast cancer; however, currently, it is used in many off-label indications. Objective To investigate the prevalence of tamoxifen off-label prescribing and explore available scientific evidence that supports those uses in outpatients. Setting Xiamen maternity and child health care hospital in Xiamen city of China. Method All the prescriptions of outpatients receiving tamoxifen were exported from an electronic prescribing system during a 1-year period. Tamoxifen use was then classified as either on- or off-label according to the criteria we established previously, and the details of the off-label prescriptions were collected. Logistic regression was applied to explore predictive variables. Evidence search was limited to Up-To-Date, the Micromedex database and PubMed. Main outcome measure The rate of off-label use, risk factors identified by logistic regression and evidence exhibition. Results A total of 75% of all the prescriptions available were classified as off-label use. Hyperplasia of the breast was the most frequently prescribed off-label indication. According to the analysis of logistic regression, male patients, patients less than 34years old, and physicians with a higher professional title were more likely associated with off-label prescribing. After a search in Up-To-Date, the Micromedex database and PubMed, only male infertility, atypical hyperplasia, mastodynia, peripheral precocious puberty and gynecomastia were found to have strong evidence supporting the use of tamoxifen off-label (22.75%). Conclusion Although the off-label use of tamoxifen was common in our hospital, there was a relative shortage of evidence available supporting those uses.

Dissipation of water in urban area, mechanism and modelling with the consideration of anthropogenic impacts: A case study in Xiamen

Dissipation of water (evapotranspiration and water vapor conversion in human water use activities) is one of the significant hydrological processes in urban area, which becomes more complicated with rapid urbanization. However, there are few systematic studies on water dissipation problems in urban area, and even the related concepts are unclear. This paper proposed the concept of urban water dissipation (UWD) to describe water vapor conversion in urban areas, and presented analysis on mechanism of UWD based on observing and monitoring experiments. The urban underlying surface was divided into five categories: buildings, paved ground, vegetation, water surface, and soil, in which the buildings have been scarcely discussed in terms of water dissipation. The dissipation of water in buildings plays a more and more important role in the urban water circulation system, as the water supply increases in urban areas. To reveal how much water is dissipated in the buildings, the main water dissipation processes in different kinds of buildings were analyzed, and the quantitative model was proposed. Based on the traditional evapotranspiration models for urban underlying surface and the proposed model for water dissipation in buildings, a new modelling system was built to simulate the total UWD. The new model system reflects the impact of human water use activities on urban water dissipation. It was applied in Xiamen city to simulate the UWD in 2000, 2005, 2010, and 2015. The results show that the UWD intensity increased with the urbanization process in Xiamen urban area in past 15 years. The UWD contribution rate increased for most land use types, except green land. For example, the water dissipation on residential land is the fastest growing one of all land use types, and its contribution rate surpassed that of green land to become the largest contributor in 2010. Because of the interference of strong human activities, the contribution rate of water dissipation on the social side continues increasing. The contribution rate of UWD on the social side was more than 40% in 2015, and it is still increasing.

Spatiotemporal Influence of Urban Environment on Taxi Ridership Using Geographically and Temporally Weighted Regression

Taxicabs play an important role in urban transit systems, and their ridership is significantly influenced by the urban built environment. The intricate relationship between taxi ridership and the urban environment has been explored using either conventional ordinary least squares (OLS) regression or geographically weighted regression (GWR). However, time constitutes a significant dimension, particularly when analyzing spatiotemporal hourly taxi ridership, which is not effectively incorporated into conventional models. In this study, the geographically and temporally weighted regression (GTWR) model was applied to model the spatiotemporal heterogeneity of hourly taxi ridership, and visualize the spatial and temporal coefficient variations. To test the performance of the GTWR model, an empirical study was implemented for Xiamen city in China using a set of weekday taxi pickup point data. Using point-of-interest (POI) data, hourly taxi ridership was analyzed by incorporating it to various spatially urban environment variables based on a 500 × 500 m grid unit. Compared to the OLS and GWR, the GTWR model obtained the best performance, both in terms of model fit and explanatory accuracy. Moreover, the urban environment was revealed to have a significant impact on taxi ridership. Road density was found to decrease the number of taxi trips in particular places, and the density of bus stops competed with taxi ridership over time. The GTWR modelling provides valuable insights for investigating taxi ridership variation as a function of spatiotemporal urban environment variables, thereby facilitating an optimal allocation of taxi resources and transportation planning.

In-use product and steel stocks sustaining the urbanization of Xiamen, China

ABSTRACT Introduction: In-use product and material stocks are the amount of concerned manufactured products and materials in active use, and are essential components of urban ecosystem. Methods: This study estimates the dynamic in-use stocks of steel-containing products and steel in the city of Xiamen, China, during 1980–2015 by applying a bottom-up accounting approach. We incorporate 55 categories of steel-containing products that are classified into five end-use sectors (i.e., buildings, infrastructure, transportation equipment, machinery, and domestic appliances). Outcomes and Discussion: In-use stocks of 51% of the studied products kept increasing during 1980–2015, especially after 2000. Steel stocks have grown up to 4.9 ± 1.4 tons per capita (t/cap) in 2015, from 0.5 ± 0.2 t/cap in 1980. Buildings are the largest reservoirs, although its share decreased from 89% in 1980 to 68% in 2015. The dynamic spatial distribution indicates that steel stocks gradually expanded from urban core to suburban areas. Conclusion: Theresults help to explore how a city’s urbanization is sustained by the in-use stocks growth. In-use steel stocks, of which the growth is highly correlated to and probably driven by the population growth, GDP increase, and urban built-up area expansion, may serve as a supplementary indicator for urbanization.

Seasonality of the transmissibility of hand, foot and mouth disease: a modelling study in Xiamen City, China.

This study attempts to figure out the seasonality of the transmissibility of hand, foot and mouth disease (HFMD). A mathematical model was established to calculate the transmissibility based on the reported data for HFMD in Xiamen City, China from 2014 to 2018. The transmissibility was measured by effective reproduction number (Reff) in order to evaluate the seasonal characteristics of HFMD. A total of 43 659 HFMD cases were reported in Xiamen, for the period 2014 to 2018. The median of annual incidence was 221.87 per 100 000 persons (range: 167.98/100,000-283.34/100 000). The reported data had a great fitting effect with the model (R2 = 0.9212, P < 0.0001), it has been shown that there are two epidemic peaks of HFMD in Xiamen every year. Both incidence and effective reproduction number had seasonal characteristics. The peak of incidence, 1-2 months later than the effective reproduction number, occurred in Summer and Autumn, that is, June and October each year. Both the incidence and transmissibility of HFMD have obvious seasonal characteristics, and two annual epidemic peaks as well. The peak of incidence is 1-2 months later than Reff.

基于能值的陆域受威胁和濒危物种价值估算——以福建省厦门市为例

PDF HTML阅读 XML下载 导出引用 引用提醒 基于能值的陆域受威胁和濒危物种价值估算——以福建省厦门市为例 DOI: 10.5846/stxb201803080461 作者: 作者单位: 中国环境科学研究院,中国环境科学研究院,福建省环境科学研究院,中国环境科学研究院,中国环境科学研究院,生态环境部信息中心,中国环境科学研究院 作者简介: 通讯作者: 中图分类号: 基金项目: 国家重点研发计划项目（2016YFC0500205）；国家自然科学基金青年科学基金项目（41501381）；中国工程院重点咨询项目（2017-ZD-09-01） Emergy-based assessment of threatened and endangered terrestrial species: A case study from Xiamen City, Fujian Province Author: Affiliation: Chinese Research Academy of Environmental Sciences,Chinese Research Academy of Environmental Sciences,Fujian Research Academy of Environmental Sciences,Chinese Research Academy of Environmental Sciences,,, Fund Project: National Key Research and Development Plan 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:开展受威胁和濒危物种价值评估是生物多样性研究的关键问题之一。当前受威胁和濒危物种研究正处于濒危等级界定和保护优先性确定阶段，存在不同保护等级交叉管理、价值评估方法欠缺及重复性计算等多方面问题。利用IUCN濒危等级和中国特有种等级名录确定厦门市不同濒危等级物种数，在此基础上利用能值转换率和修正的中国能值/货币比率对厦门市陆域受威胁和濒危物种价值进行估算。结果显示，通过多途径整理纳入估算的厦门市陆域野生动植物物种数为1444种，其中受威胁和濒危物种数为318种；2015年厦门市物种能值价值约为3.53×1011元，2010年约为3.08×1011元，其中两期受威胁和濒危物种能值价值均占物种总价值的88.31%；中国特有种等级对价值贡献最大达73.25%，其次是IUCN濒危等级达23.24%。研究表明，能值评估法能够客观凸显受威胁和濒危物种价值，研究结果可为生物多样性及物种保育的管理决策提供技术支撑。 Abstract:The implementation of value assessments and analysis of the effectiveness of protection of different types of threatened and endangered species has become a key issue in biodiversity research. Current research into threatened and endangered species focuses on defining the level of endangerment and determining the priority of protection, and it is subject to problems, such as cross-management of different protection levels, lack of value assessment methods, and repetitive calculations. In this study, the number of different endangered species in Xiamen was determined using the IUCN endangered grade and the list of endemic species in China. Based on this, the emergy/GDP ratio was used to estimate the number of threatened and endangered species in Xiamen City. According to the collected, summarized, and analyzed results, there are 1444 terrestrial wildlife species in Xiamen, of which 318 are threatened or endangered. The estimated emergy value of those species was found to be approximately 3.53×1011 yuan in 2015 and about 3.08×1011 yuan in 2010. The emergy value of threatened and endangered species in the two periods accounted for 88.31% of the total value of the species. The endemic species hierarchy in China contributed 73.25% of the emergy value, but the contribution rate of the IUCN endangerment classification was 23.24%. Research indicates that the emergy assessment method can highlight the value of threatened and endangered species in an objective manner. These results can provide technical support for decision-making in biodiversity and species conservation management. 参考文献 相似文献 引证文献

Study on Coastline Changes of Xiamen City Based on Remote Sensing Images

Based on the Landsat remote sensing data, this paper had monitored the coastline changes of Xiamen city in recent 20 years. By extracting the coastline vector data of 1999, 2005, 2011 and 2017 respectively, the spatio-temporal characteristics of coastline changes on coastline length, change rate and land change area were analyzed, and the main driving factors were analyzed combined with the land use changes in the coastal swing area. The results show that: the total length of Xiamen's coastline increased from 235.16 km to 264.98 km during 1999-2017, and the land area increased from 1558.84 km2 to 1594.29 km2. The most significant changes occurred in Xiang'an district and Huli district with the coastline length increased by 16.38% during 2011-2017 and 22.14% during 1999-2005 respectively, while the changes were not very conspicuous in other areas. According to the land use changes in the coastal areas, the coastline changes in Xiamen City were mainly related to the expansion of construction land and port constructions in Haicang district, Xiang'an district and Huli district, as well as the expansion of aquaculture in the Xiang'an district.

厦门后溪水质与流域景观特征沿城乡梯度的变化分析

厦门后溪水质与流域景观特征沿城乡梯度的变化分析

厦门市幼儿园啦啦操发展过程中存在的问题及对策研究

厦门市幼儿园啦啦操发展过程中存在的问题及对策研究

The Study of Drinking Water Quality in Jimei District of Xiamen City

With the acceleration of urbanization in China, the demand for water is increasing, and the consequent problem of drinking water safety is attracting more and more attention. This experiment is aim to learn about the water quality in Xiamen, and the water quality of water resources, the waterworks and users were collected and analyzed. The results showed that the water quality of water sources is reach to class II of the national water quality standards. The chromaticity, turbidity, conductivity, residual chlorine and bacterial colony of the water from both the waterworks and users were lower than the national standard. The total number of E. coli, cadmium and lead were not detected in domestic water in Jimei district. Based on the analysis of the water quality from the waterworks and the users, it may deduce that the pipe material in this area met the relevant requirements and did not cause secondary pollution.

Towards Sustainable Urban Communities: A Composite Spatial Accessibility Assessment for Residential Suitability Based on Network Big Data

Suitable allocation of residential public services is vital to realizing sustainable communities and cities. By combining network big data and spatial analysis, we developed a composite spatial accessibility assessment method for residential suitability of urban public services covering healthcare, leisure, commerce, transportation, and education services. Xiamen City, China is the test site. We found that although most facilities were concentrated on Xiamen Island, there were shortages in the per capita transportation and education service supplements compared with the average performance of Xiamen City because of the high local population. Meanwhile, Tong’an had advantages in the amount of public facilities due to its long history of regional development. However, high-quality facilities were deficient there as well as in other off-island districts. The residential communities surrounding transportation, commerce, and healthcare facilities had a similar allocation pattern in Xiamen City, whereas the residential accessibility of education and leisure services showed regional differences. Due to unbalanced regional development, evident inequality could be witnessed by comparing the composite assessment results of residential suitability between the communities on Xiamen Island and those in the off-island Areas. Our study hopes to provide dedicated support for designing sustainable communities and cities, especially for those in developing countries.

Comprehensive Analysis of Nitrogen Deposition in Urban Ecosystem: A Case Study of Xiamen City, China

Atmospheric nitrogen deposition can supply nitrogen for ecosystems while posing a serious threat to ecological security. An assessment of the ecological risks caused by atmospheric nitrogen deposition is critical for urban sustainable development. Based on “Ecological Risk Analysis” and the “Driver-Pressure-State-Response (DPSR) framework,” this paper established a comprehensive ecological risk assessment model and assessed the ecological risk of nitrogen deposition in Xiamen City, China. The results showed that the risk from nitrogen deposition to the forest ecosystem is high due to the impact of nitrogen deposition on the residual rate of litter and survival rate of seedlings. The risks to freshwater and marine ecosystems were determined to be high and moderate, respectively, due to the promotion of eutrophication by nitrogen. The risk to farm ecosystems was low due to the impact on weeds. The proportion of high-risk areas in Xiamen City was 37.1%. Among the districts of Xiamen City, Tong’an and Xiang’an had the highest proportion of high-risk areas (48%) and low-risk areas (31.8%), respectively.

Source apportionment of metal elements in PM2.5 in a coastal city in Southeast China: Combined Pb-Sr-Nd isotopes with PMF method

Combined Pb-Sr-Nd isotopes tracing technique with positive matrix factorization (PMF) analysis was used for source apportionment of metal elements in PM2.5 from Xiamen city, a coastal city in Southeast China. The results showed that the mean concentration of metal elements in PM2.5 in winter was 51.92% higher than that in summer. The air-mass backward trajectory analysis suggested that PM2.5 in Xiamen was significantly influenced by local sources during the sampling period. According to our study, metal elements in PM2.5 were mainly from plating and alloy industry and coal combustion, followed by soil and construction dusts, while traffic exhausts played a minor role. The carcinogenic risk value to human of Cr, Co, Ni and Cd, which mainly came from plating and alloy industry and soil and construction dusts, were exceeded the safe value (10−6), indicating the relative control measures should be taken for the above elements in PM2.5.

A Bi-Objective Pseudo-Interval T2 Linear Programming Approach and Its Application to Water Resources Management Under Uncertainty

In realistic water resource planning, fuzzy constraints can be violated but still allowed to certain acceptance degrees. To address this issue, in this study, a bi-objective pseudo-interval type 2 (T2) linear programming approach with a ranking order relation between the intervals is proposed for water system allocation. This developed approach can transform normal T2 fuzzy sets, including both trapezoidal and triangular types, into the bi-objective linear programming approach solved with the proposed algorithm with mathematical rigor, which improves the flexibility of the decision supports. The new model is applied in the utilization of regional water resource management in Xiamen city, China. Concurrently, a local water system model is established by considering the aspects of industrial, agricultural, and municipal requirements. Thus, by analysis of the solution algorithm, decision-makers can obtain different optimal results by selecting different acceptance degrees. The results also demonstrate the superiority of the proposed method. Therefore, this approach not only augments the theory of the optimal allocation method in water resource management, but also provides the support for meeting the requirements of the 13th five-year plan for Xiamen ecological planning.