Spatial variability and pattern analysis of soil properties in Dehui city, Jilin province

1IntroductionSoil nutrient, as the synthetic results under the influence of various anthropogenic activities and the factors such as climate and topography, etc., possesses certain spatial distribution characteristics, and certain structural and stochastic characteristics. The study of the differences existing in different parts of the region lays the foundation for adjusting all management measures and all material input capacities and for gaining the maximal economic benefit. Presently, the …     

呼和浩特市城市边缘区景观格局动态变化研究

利用GIS技术对1987，2000年两期航空遥感影像进行空间叠加对比分析，从斑块及景观2个尺度对呼和浩特市城市边缘区景观格局变化进行了研究。结果表明：在斑块尺度上，边缘区两期景观结构均以农田景观为基质，研究期内，农田景观、草地景观等缓慢减少，建筑景观明显增多；在景观尺度上，边缘区景观多样性指数趋于增大，优势度指数趋于降低．景观组分趋于复杂化、破碎化和多元化。分析其影响因素可知：经济发展和城市化的加快、政策导向是变化的根本原因，人口的增加、土地利用方式的改变是变化的直接原因。     

论数字城市工程及其技术体系

分析了数字城市的内涵 ,基于数字工程思想 ,总结了数字城市的工程结构与技术体系 ,进而阐述了数字城市的意义与建设策略。     

基于图论的树状河系结构化绘制模型研究

结合树状河系自身的结构特点和图论的思想，提出了基于图论的河系结构化绘制模型的建立，利用图论的思想描述了河系的结构并建立其自动符号化模型，阐述了主流、流向自动确定和结构化绘制实现的详细算法，并对通用图形数据格式DXF文件记录的河系数据进行了测试。     

IGGOS as a potential partner in IGOS

This short note reviews our thinking on how IGGOS can best achieve a high status within the set of global monitoring programmes. If such a high status can be obtained, then the importance of geodetic networks and services will be recognized more widely, and their activities will consequently be better resourced in the long term. One particular aspect concerns how IGGOS can complement the roles of the various IGOS partners within global monitoring. The different ways in which IGGOS can contribute to IGOS are outlined.     

The International GPS Service tracking network: Enabling diverse studies and projects through international cooperation

The International GPS Service (IGS), formulated beginning in 1989 and formalized in 1994, was founded on the collaborative operation of approximately 30 permanent GPS stations to benefit global geodynamics. The same cooperative principles, today applied to a network of over 300 stations, still serve to maximize global benefit without unnecessary duplication of investment in global infrastructure. The scope of applications of the dataset has grown to include atmospheric, oceanographic, subdaily, and low-earth orbiter activities through working groups and pilot projects fostered within the IGS in the now traditional IGS spirit of collaboration. These activities and the IGS infrastructure are viewed as critical elements to the Global Geodetic Observing System. This presentation will review the present nature of the IGS tracking network and its ability to support new applications.     

Assessing the Comparability of Ammonium,Nitrate and Sulfate Concentrations Measured by Three Air Quality Monitoring Networks

Airborne fine particulate matter across the United States is monitored by different networks, the three prevalent ones presently being the Clean Air Status and Trend Network (CASTNet), the Interagency Monitoring of PROtected Visual Environment Network (IMPROVE) and the Speciation and Trend Network (STN). If combined, these three networks provide speciated fine particulate data at several hundred locations throughout the United States. Yet, differences in sampling protocols and samples handling may not allow their joint use. With these concerns in mind, the objective of this study is to assess the spatial and temporal comparability of the sulfate, nitrate and ammonium concentrations reported by each of these networks. One of the major differences between networks is the sampling frequency they adopted. While CASTNet measures pollution levels on seven-day integrated samples, STN and IMPROVE data pertain to 24-hour samples collected every three days. STN and IMPROVE data therefore exhibit considerably more short-term variability than their CASTNet counterpart. We show that, despite their apparent incongruity, averaging the data with a window size of four to six weeks is sufficient to remove the effects of differences in sampling frequency and duration and allow meaningful comparison of the signals reported by the three networks of concern. After averaging, all the sulfate and, to a lesser degree, ammonium concentrations reported are fairly similar. Nitrate concentrations, on the other hand, are still divergent. We speculate that this divergence originates from the different types of filters used to collect particulate nitrate. Finally, using a rotated principal component technique (RPCA), we determined the number and the geographical organization of the significant temporal modes of variation (clusters) detected by each network for the three pollutants of interest. For sulfate and ammonium, the clusters’ geographical boundaries established for each network and the modes of variations within each cluster seem to correspond. RPCA erformed on nitrate concentrations revealed that, for the CASTNet and IMPROVE networks, the modes of variation do not correspond to unified geographical regions but are found more sporadically. For STN, the clustered areas are unified and easily delineable. We conclude that the possibility of jointly using the data collected by CASTNet, IMPROVE and STN has to be weighed pollutant by pollutant. While sulfate and ammonium data show some potential for joint use, at this point, combining the nitrate data from these monitoring networks may not be a judicious choice.     

The diurnal and seasonal characteristics of urban heat island variation in Beijing city and surrounding areas and impact factors based on remote sensing satellite data

Based on the land surface temperature (LST), the land cover classification map,vegetation coverage, and surface evapotranspiration derived from EOS-MODIS satellite data, and by the use of GIS spatial analytic technique and multivariate statistical analysis method, the urban heat island (UHI) spatial distribution of the diurnal and seasonal variabilities and its driving forces are studied in Beijing city and surrounding areas in 2001. The relationships among UHI distribution and landcover categories, topographic factor, vegetation greenness, and surface evapotranspiration are analyzed. The results indicate that: (i) The significant UHI occur in Beijing city areas in the four seasons due to high heat capacity and multi-reflection of compression building, as well as with special topographic features of its three sides surrounded by mountains,especially in the summer. The UHI spatial distribution is corresponding with the urban geometry structure profile. The LST difference is approximately 4-6℃ between Beijing city and suburb areas, comparatively is 8- 10℃ between Beijing city area and outer suburb area in northwestern regions. (ii) The UHI distribution and intensity in daytime are different from nighttime in Beijing city area, the nighttime UHI is obvious. However, in the daytime, the significant UHI mainly appears in the summer, the autumn takes second place, and the UHI in the winter and the spring seem not obvious. The surface evapotranspiration in suburb areas is larger than that in urban areas in the summer, and high latent heat exchange is evident, which leads to LST difference between city area and suburb area. (iii) The reflection of surface landcover categories is sensitive to the UHI, the correlation between vegetation greenness and UHI shows obviously negative.The scatterplot shows that there is the negative correlation between NDVI and LST (R2 = 0.6481).The results demonstrate that the vegetation greenness is an important factor for reducing the UHI,and large-scale construction of greenbelts can considerably reduce the UHI effect.     

Interlocking directorships and trans-national linkages within the British Empire, 1900–1930

Recent research has highlighted the value of employing the idea of networks to describe the interrelatedness of today's globalizing economy. Networks facilitate flows of knowledge, ideas, managerial techniques and capital between firms both within and across political borders. This paper argues that the reconstruction of social connections through which information is created, given value and exchanged is fundamental to an understanding of not only contemporary but also historical patterns of economic globalization. We focus on the networks of the capitalist elite running 12 major multinational enterprises, active across British imperial territories, between c .1900 and c .1930. An examination is made of the economic and spatial interlocks between firms created by board members who were multiple directors. Social underpinnings of multiple directorates are examined by exploring the common, overlapping social spheres within which individuals engaged. A clearer grasp of the ways in which corporate activity operated in the early 1900s can provide a better understanding of the social context of global economic operations.     

Understanding governance and networks: EU-US interactions and the regulation of genetically modified organisms

EU-US (European Union-United States) interactions in relation to the regulation of genetically modified organisms (GMOs) have been examined in detail in recent years. To do this scholars have tended to focus on a small number of high profile processes, such as the formal complaint of the US to the World Trade Organisation regarding the regulation of GMOs in the Europe. It is important to analyse developments of this kind but overemphasis on them has also lead to a distorted view of the case and a failure to appreciate the significance of other, less visible, types of interaction. In this paper we focus instead on trying to understand the roles played by various EU-US transnational networks—The Transatlantic Business Dialogue, The Transatlantic Economic Partnership, The Transatlantic Consumer Dialogue, The Transatlantic Environmental Dialogue and the EU-US Consultative Forum on Biotechnology. These networks have been trying to shape the regulation of GMOs in both jurisdictions since the mid 1990s. By analysing them through a ‘governance lens’ we find that we can better understand EU-US interactions and the dynamics and influences around the regulation of GMOs. This gives us valuable insights into processes of contemporary governance.