An Zhang

Population Exposure to PM2.5 in the Urban Area of Beijing

The air quality in Beijing, especially its PM2.5 level, has become of increasing public concern because of its importance and sensitivity related to health risks. A set of monitored PM2.5 data from 31 stations, released for the first time by the Beijing Environmental Protection Bureau, covering 37 days during autumn 2012, was processed using spatial interpolation and overlay analysis. Following analyses of these data, a distribution map of cumulative exceedance days of PM2.5 and a temporal variation map of PM2.5 for Beijing have been drawn. Computational and analytical results show periodic and directional trends of PM2.5 spreading and congregating in space, which reveals the regulation of PM2.5 overexposure on a discontinuous medium-term scale. With regard to the cumulative effect of PM2.5 on the human body, the harm from lower intensity overexposure in the medium term, and higher overexposure in the short term, are both obvious. Therefore, data of population distribution were integrated into the aforementioned PM2.5 spatial spectrum map. A spatial statistical analysis revealed the patterns of PM2.5 gross exposure and exposure probability of residents in the Beijing urban area. The methods and conclusions of this research reveal relationships between long-term overexposure to PM2.5 and people living in high-exposure areas of Beijing, during the autumn of 2012.

The Association between Air Pollution and Population Health Risk for Respiratory Infection: A Case Study of Shenzhen, China

Nowadays, most of the research on air pollution and its adverse effects on public health in China has focused on megacities and heavily-polluted regions. Fewer studies have focused on cities that are slightly polluted. Shenzhen used to have a favorable air environment, but its air quality has deteriorated gradually as a result of development in recent years. So far, no systematic investigations have been conducted on the adverse effects of air pollution on public health in Shenzhen. This research has applied a time series analysis model to study the possible association between different types of air pollution and respiratory hospital admission in Shenzhen in 2013. Respiratory hospital admission was divided into two categories for comparison analysis among various population groups: acute upper respiratory infection and acute lower respiratory infection. The results showed that short-term exposure to ambient air pollution was significantly associated with acute respiratory infection hospital admission in Shenzhen in 2013. Children under 14 years old were the main susceptible population of acute respiratory infection due to air pollution. PM10, PM2.5 and NO2 were the primary air pollutants threatening respiratory health in Shenzhen. Though air pollution level is generally relatively low in Shenzhen, it will benefit public health to control the pollution of particulate matter as well as other gaseous pollutants.

Pattern of Spatial Distribution and Temporal Variation of Atmospheric Pollutants during 2013 in Shenzhen, China

Air pollution caused by atmospheric particulate and gaseous pollutants has drawn broad public concern globally. In this paper, the spatial-temporal distributions of major air pollutants in Shenzhen from March 2013 to February 2014 are discussed. In this study, ground-site monitoring data from 19 monitoring sites was used and spatial interpolation and spatial autocorrelation methods were applied to analyze both spatial and temporal characteristics of air pollutants in Shenzhen City. During the study period, the daily average concentrations of Particulate Matter (PM10 and PM2.5) ranged from 16–189 μg/m3 and 10–136 μg/m3, respectively, with 13 and 44 over-limit days, indicating that particulate matter was the primary air pollutant in Shenzhen. The highest PM occupation in the polluted air was observed in winter, indicating that fine particulate pollution was most serious in winter. Meanwhile, seasonal agglomeration patterns for six kinds of air pollutants showed that Guangming, Baoan, Nanshan, and the northern part of Longgang were the most polluted areas and PMs were their primary air pollutants. In addition, wind scale and rainfall played an important role in dissipating air pollutant in Shenzhen. The wind direction impacted the air pollution level in Shenzhen in multiple ways: the highest concentrations for all air pollutants all occurred on days with a northeast wind; the second highest ones appeared on the days with no wind. The concentrations on days with north-related winds are higher on average than those of days with south-related winds.

Ecological Niche Modeling Identifies Fine-Scale Areas at High Risk of Dengue Fever in the Pearl River Delta, China

Dengue fever (DF) is one of the most common and rapidly spreading mosquito-borne viral diseases in tropical and subtropical regions. In recent years, this imported disease has posed a serious threat to public health in China, especially in the Pearl River Delta (PRD). Although the severity of DF outbreaks in the PRD is generally associated with known risk factors, fine scale assessments of areas at high risk for DF outbreaks are limited. We built five ecological niche models to identify such areas including a variety of climatic, environmental, and socioeconomic variables, as well as, in some models, extracted principal components. All the models we tested accurately identified the risk of DF, the area under the receiver operating characteristic curve (AUC) were greater than 0.8, but the model using all original variables was the most accurate (AUC = 0.906). Socioeconomic variables had a greater impact on this model (total contribution 55.27%) than climatic and environmental variables (total contribution 44.93%). We found the highest risk of DF outbreaks on the border of Guangzhou and Foshan (in the central PRD), and in northern Zhongshan (in the southern PRD). Our fine-scale results may help health agencies to focus epidemic monitoring tightly on the areas at highest risk of DF outbreaks.

GeoRSS Based Emergency Response Information Sharing and Visualization

Spatial information played a very important role in these emergency responses. Map can easily show where and how the emergency event is happening. In order to map the emergency response information on real time, Geographically Encoded Objects for RSS (Really Simple Syndication) feeds which called GeoRSS technology is used. GeoRSS technology is a way to encode location in RSS feeds. GeoRSS could provide an easy way for emergency response teams to pool information onto one central map. An example demo of forest fire will be shown how to share and visualizing the emergency information based on GeoRSS. In the end, we will talk about the tendency of the GeoRSS and the future work.

Research about the location technologies of forest fire detecting based on GIS

Forest fire caused damages of property and loss of human life. Detecting a forest fire and get the location is very significant in the fire early warning. More early and more prompt detecting fire and determining fire position as far as possible could avoid and reduce loss of the disaster. At present there are three ways regarding the forest fire early warning and location determining which included: monitoring form Remote Sense Satellite image, manual observation and patrols, and automatic monitoring through CCD camera long-distance video. Overall evaluation regarding the three location technologies in forest fire early warning, the CCD camera detecting method is suitable in the fire rapid Response. An automatic forest fire surveillance system was running to detect the fire by using visible light images from the remote cameras. If a forest fire was detected, an alarm will be activated. The observation point elevation values, vertical offsets, horizontal and vertical scanning angles, and scanning distances will be also be sent to the central control room. The spatial orientation will be computed and showed on the electronic map. Key location technologies based on CCD camera included the image processing technique for automatically detecting forest fire and the visibility analyzes technique for the digital elevation model. Jing gang Mountain which locates in Jiangxi province of China is taken as an example. With the help of this automatic monitoring through CCD camera long-distance video and visibility analyzes, scientists and government administrators can make decision-supporting easily when they know exactly where a forest fire is. At last the shortage of CCD camera detecting method was discussed. We cannot depend on CCD camera detecting equipment and technologies only. With foundation of the automatic video frequency supervisory system, we should also strengthen manual observation and satellite remote sensing monitor.

The abstraction method research of river network based on catchments' characters deriving digital elevation data

The extraction of drainage networks and catchment boundaries from digital elevation models (DEMs) has received considerable attention in recent years and is recognized as a viable alternative to traditional surveys and the manual evaluation of topographic maps. Digital data on the position and characteristics of river networks and catchments are important for the analysis of water resources. GIS tools allow for the combined analysis of digital elevation data and environmental parameters in order to derive this kind of information. In this paper we present an application that selecting river network deriving digital elevation data. In this application, we use catchments as the unit of river abstraction. Many researchers took catchments as the base of hydrographic model because the catchments deriving from digital elevation data can reflect the characteristics of terrain which is the foundation of the river network. In the abstraction of river network, how to keep the structure of the river network after abstraction is the very important issue. This is why we choose the catchments deriving from digital elevation models as the unit of our generalization research. Considering the complication of the structure of river network, in this paper, we only choose three drainage patterns which are dendritic drainage patterns, featherlike drainage patterns, and Parallel drainage patterns as the examples of the research. From the results of research, it can not only keep the density of the river network, but also keep the structure of the river network.

Color on emergency mapping

There are so many emergency issues in our daily life. Such as typhoons, tsunamis, earthquake, fires, floods, epidemics, etc. These emergencies made people lose their lives and their belongings. Every day, every hour, even every minute people probably face the emergency, so how to handle it and how to decrease its hurt are the matters people care most. If we can map it exactly before or after the emergencies; it will be helpful to the emergency researchers and people who live in the emergency place. So , through the emergency map, before emergency is occurring we can predict the situation, such as when and where the emergency will be happen; where people can refuge, etc. After disaster, we can also easily assess the lost, discuss the cause and make the lost less. The primary effect of mapping is offering information to the people who care about the emergency and the researcher who want to study it. Mapping allows the viewers to get a spatial sense of hazard. It can also provide the clues to study the relationship of the phenomenon in emergency. Color, as the basic element of the map, it can simplify and clarify the phenomenon. Color can also affects the general perceptibility of the map, and elicits subjective reactions to the map. It is to say, structure, readability, and the readers psychological reactions can be affected by the use of color.

Study on Virtual Geographic Environment for Ecosystem Monitoring and Management in Lancang River Basin

Virtual Geographic Environment is an avatar-based humans and 3d virtual worlds. Because of the avatar-based humans participation, VGE helps people to make decision based on the understanding of the virtual geographic environment. This paper takes the Lancang River basin as study area which located in the border area of Yunnan province, China. In order to monitor and manage the ecosystem in Lancang River basin, a virtual geographic environment is designed and developed based on a Client/Server structure. A virtual geographic environment Client is developed based on ArcGIS Engine. The client accesses the database though the ArcSDE. The client can help people explore virtual ecosystem in Lancang River basin. The viewer can immerse interact and image in a 3d sense. The viewer can also implement multi layer data query, 3d terrain analysis, spatial analysis, dynamic ecosystem model simulation, such as flood simulation, wild fire simulation etc. In the virtual geographic environment we do not only pay attention to the visualization but also the cognizance. The ecological styles in Lancang River basin are analyzed in 3 different periods (1970s, 1990s, and 2000s) based on the RS images in the 3D scene. The changes of the ecological styles also are analyzed. Several ecosystem models are simulated in 3d scene. The regions where have ecological environment problem will be marked and monitored. After the complex understanding of the virtual geographic environment in Lancang River, a sustainable development strategy can be made to give advice to the study area.

The thematic mapping system on internet

Thematic Mapping Services (TMS) is about providing thematic mapping and analysis as a service way on internet. After the Internet Google launch Google Maps on the Internet in 2005, map application on the Internet appeared in large numbers. A large number of developers through the Google map API mashups maps out a wide variety of applications. With the concept of Web2.0, sharing a large number of open API, the coupling between data services and application services, made geographic visualization with the development of logical analysis. Developers to leverage some of the Governments statistical analysis of data, combined with Google map, super imposed out of a variety of applications, such as: revenue analysis of people in the Chicago area, the earthquake damage in Haiti and so forth. The paper is discussing the new ways and means of thematic mapping in the internet environment to make the maps express more dynamic, more lively and easier to understand.