Statistical analysis of spatial data in the presence of missing observations: a methodological guide and an application to urban census data

"In this paper a simple introduction and guide to a widely applicable method for estimating missing data in fields of enquiry such as census maps or LANDSAT images are presented. The method given is a maximum likelihood procedure.... The algorithm is presented in the form of a simple tutorial guide. An example, of median income levels in Houston [Texas], is worked through in detail for missing cells in census data. The example is characterised by a variable mean and a general variance-covariance matrix."     

Using census data to investigate the causes of the ecological fallacy

"The authors show how data from the 2% Sample of Anonymised Records (SAR) can be combined with data from the Small Area Statistics (SAS) database to investigate the causes of the ecological fallacy in an Enumeration District (ED) level analysis. A range of census variables are examined in three ?SAR districts'...in England. Results of comparable analyses from the 1986 Australian census are also given. The ecological fallacy arises when results from an analysis based on area-level aggregate statistics are incorrectly assumed to apply at the individual level.... A methodology is introduced which allows aggregate-level statistics to be adjusted by using individual-level information on those variables that explain much of the within-area homogeneity."     

Household modelling and forecasting--dynamic approaches with use of linked census data

The author proposes improved methods of household modeling, using dynamic models rather than the headship rate method. "Reasons are discussed why this method has been criticised in recent years.... The advantages of dynamic models are discussed, and a number of alternative dynamic models of household formation and dissolution are presented. The data source used is the Office of Population Censuses and Surveys 1% longitudinal study, which contains linked information on 500,000 people in the 1971 and 1981 England and Wales Censuses of Population."     

A multivariate classification of individual household census data for Italy

Never before have regional scientists had access to individual census data for an entire country. The paper describes the application of a taxonomic procedure to classify the 15.6 million households identified by the 1971 Italian census. The results are important both for what they reveal about Italian social structure and because they provide a basis for a constructing aggregate census data so that within area variations are retained.     

The generation of spatial population distributions from census centroid data

"Census data are commonly used in geographical analysis and to inform planning purposes, though at the disaggregate level the basis of enumeration poses difficulties. In this paper an approach to surface generation is described that offers the prospect of revealing an underlying population distribution from centroid-based data which is independent of zonal geography. It is suggested that this can serve a wide variety of analytical, cartographic, and policy purposes, including the creation of spatial indicators of economic and social conditions and enhancing the value of census data. The approach is illustrated by reference to an analysis of part of the valleys of South Wales, in the United Kingdom."     

重大危险源数字化普查信息系统设计分析

重大危险源资料的标准化、数字化是实现资源共享和优化配置,提升安全管理水平的重要技术途径.以Vc 为主编语言、SQL为后台支持数据库的重大危险源普查信息系统,采用通用化技术与个性化设计相结合的技术路线,在分析重大危险源动态特性和安全管理信息需求的基础上,设计了包含了5个功能菜单和多类型基础数据的企业版和管理版2种版本,并设置了信息录入标准模板、分类管理、统计分析和多类型输出等系列功能.应用实践表明,该软件为重大危险源安全管理的标准化和数字化提供了重要技术手段.     

Indexing the census: a by-product of the simulation of whole populations by means of SAS and SAR data

"Amongst the new output formats adopted for the 1991 [U.K.] census were the Small Area and Local Base Statistics tables and the Samples of Anonymised Records. During an attempt to combine these data sources to estimate whole populations, a need was recognised for a computer algorithm to aggregate SAR data flexibly into LBS and SAS table look-alikes. This paper is a report on progress in the development of such an algorithm, including the concomitant development of a meta-database of census tables and variables required as an input to the algorithm. Out of this work a user-friendly, freely disseminable version of the census meta-database has been created, of interest to all census users."     

Research using the 1991 census of population: development of tools for analysis

This is an introductory editorial to a selection of papers focusing on research using data from the 1991 census of the United Kingdom. The emphasis is on the increase in such research due to the availability of the data in machine-readable format and on the development of tools for analysis of the data.     

Research policy and review 30. How to add value to migration data from the 1991 census

"The form in which migration information is likely to be provided from the 1991 Census [of the United Kingdom] is reviewed, and suggestions are made about how this provision can be improved for the academic research community, building on the experience of the 1981 Census. The recommendations add considerable value to the information at relatively low cost."     

Estimating actual areal evapotranspiration from potential evapotranspiration using physical models based on complementary relationships and meteorological data

The potential evapotranspiration E _p , which is controlled by the atmospheric conditions and the saturation vapour pressure at the actual surface temperature, represents an upper limit to evapotranspiration from a wet soil-plant surface. The actual evapotranspiration E is the amount of water that evapotranspirates to the atmosphere under given energy and climatic conditions. According to Bouchet, dE+dE _p =0. The author has verified the relationship using the measured data of pan evaporation. Both Morton and Brutsaert and Stricker applied the Bouchet's complementary relationship as the basis of their models and used Penman's model for E _p . The author has used both the models to estimate E in the USA, South America and India from meteorological data such as precipitation, temperature, vapour pressure, wind velocity, and solar radiation. This method enables E to be estimated anywhere in the world, especially where the supply of water is less abundant.     

Using census data: religion as a key variable in studies of Northern Ireland

"For the first time since a question on religion was first included in the Census of Population (in 1861), the recently published results of the 1991 Census show that less than half of the population of Northern Ireland declared themselves as belonging to a Protestant Christian denomination. Discussions surrounding the future political and constitutional arrangements for Northern Ireland frequently include evidence adduced about the relative size of the two 'tribes' widely identified by the labels 'Protestant' and 'Catholic'. The major source of that evidence comes from the question on religion contained in the Northern Ireland Census, and this paper is concerned with the nature and use of that data. The legitimacy of certain uses of the data is questioned; the reliability of the data is considered; and certain tentative findings are presented based on the data published in the (hard copy) reports."     

Developments in areal interpolation methods and GIS

This paper is a review and extension of the authors' research project on areal interpolation. It is concerned with problems arising when a region is divided into different sets of zones for different purposes, and data available for one set of zones (source zones) are needed for a different set (target zones). Standard approaches are based on the assumption that source zone data are evenly distributed within each zone, but our approach allows additional information about the target zones to be taken into account so that more accurate target zone estimates can be derived. The method used is based on the EM algorithm. Most of the work reported so far (e.g. Flowerdew and Green 1989) has been concerned with count data whose distribution can be modelled using a Poisson assumption. Such data are frequently encountered in censuses and surveys. Other types of data are more appropriately regarded as having continuous distributions. This paper is primarily concerned with areal interpolation of normally distributed data. A method is developed suitable for such data and is applied to house price data for Preston, Lancashire, starting with mean house prices in 1990 for local government wards and estimating mean house prices for postcode sectors.     

基于数值分析法的实验测试数据的处理及分析

在实验数据处理中分别运用最小二乘法和拉格朗日插值方法把得到的数据进行拟合,对比两种拟合结果,结合两者的优势,整合成一个新的拟合方程作为处理实验数据的结果,并进行了实例验证.验证结果表明,运用这种改进的数值方法得到的结果更为精确,更适合实验数据处理.     

Land development, land use, and urban sprawl in Puerto Rico integrating remote sensing and population census data

The island of Puerto Rico has both a high population density and a long history of ineffective land use planning. This study integrates geospatial technology and population census data to understand how people use and develop the lands. We define three new regions for Puerto Rico: Urban (16%), Densely Populated Rural (36%), and Sparsely Populated Rural (48%). Eleven percent of the island is composed of urban/built-up surfaces. A large part of these developments occur in both low-density patterns of construction and sparsely populated neighborhoods. Half of the urban development occurs outside of urban centers. This analysis helps differentiate zones in the landscape with different uses and conditions, identifying not only urban and rural settings, but also the interface where development occurs in a territory dominated by forests and pastures, analogous to a wildland urban interface. The ineffective plan of land development has left a high degree of urban sprawl in 40% of island, where cities and towns appear typically surrounded by sprawl. The San Juan Metropolitan Area is one of the most expanded urbanized areas with a population of 2–2.5 million, comparable with the most sprawled cities of the U.S. mainland. This study reinforces the need for an efficient land use planning, and provides information to support research and planning efforts related to land development and conservation. It represents the first approach integrating satellite imagery with population census data for studying the human environment in the Caribbean.     

Use of the census samples of anonymised records (SARs) and survey data in combination to obtain estimates at local authority level

"The Samples of Anonymised Records (SARs) provide large representative samples of 278 small areas of Britain and are thus of great value to planners. This paper describes an approach which takes advantage of the fact that the SARs comprise individual records. Estimates of the proportions of local authority populations suffering serious illness were produced by use of data from the 4th National General Practitioner Morbidity survey and the 2% anonymised sample of individual 1991 Census records. These estimates were compared with external validation criterion, all-cause mortality. The correlation was high, providing some evidence of the validity of the approach."     

Socio-spatial differentiation and residential segregation in the Chinese city based on the 2000 community-level census data: A case study of the inner city of Nanjing

Socio-spatial differentiation and residential segregation have been studied extensively in numerous cities and have contributed significantly to the understanding of urban spatial and social structures. Analyses of diverse data sets at varied spatial scales have supported the development of theoretical frameworks. However, the majority of Chinese case studies published in recent decades were dominantly based on either non-spatial data or population census data at sub-district (or jiedao in Chinese) level. These analyses have been limited through using low-resolution aggregate data resulting in incomplete or biased findings. This paper aims to examine the fine-scale socio-spatial structure of the inner city of Nanjing using the fifth population census data of 2000 at the lowest spatial scale – community (or juweihui in Chinese) level. Our findings reveal that the policies of the socialist era and the initial outcomes of the introduction of a free market, particularly with regard to the creation of new elite spaces within the inner city, have shaped a complex pattern of socio-spatial differentiation and residential segregation.     

基于地理国情普查数据的兰州市城关区土地开发建设适宜性评价研究

通过对适宜性评价模型和GIS相结合进行土地开发建设适宜性评价方法的研究,选取城关区内的评价指标因子,如地形坡度、地貌、水系、道路缓冲区、土地利用等,利用适宜性评价模型评价土地开发建设适宜性。基于GIS系统的空间分析功能,实现对空间数据叠加分析处理及评价结果图的输出,得到研究区土地开发建设适宜性评价结果,以期更准确揭示研究区土地开发建设规律,为区域城镇用地空间拓展、国土空间布局优化提供参考。