Ian N. Gregory

The accuracy of areal interpolation techniques: standardising 19th and 20th century census data to allow long-term comparisons

The census has been collected in Britain since 1801 and has published detailed attribute data at district-level about the population since 1851. Comparing censuses over the long-term is, however, highly problematic due to the problem of boundary changes. The only traditional response to this has been to aggregate data; however, this is highly unsatisfactory. The Great Britain Historical Geographical Information Systems (GIS) allows census data to be linked to the boundaries that were used to publish them, and areal interpolation techniques allow data from many dates to be standardised onto a single administrative geography to allow long-term comparison. Areal interpolation, however, inevitably introduces error and quantifying this error with real-world data is usually impossible. In this paper the accuracy of several areal interpolation techniques suitable for use with historical data are compared using “synthetic” districts and parishes created from Enumeration District-level data from the 1991 census. The errors introduced are analysed for several different variables and show that the effectiveness of the technique depends on the variable to be interpolated and the choice of target geography. While this paper is mainly applied to historical data, these results have relevance to any areal interpolation problem.

Time-variant GIS Databases of Changing Historical Administrative Boundaries: A European Comparison

The advantages of using digital boundary data as part of the process of analysing and visualising census data are well known. In many countries census data and their associated boundaries are now published as an integrated digital product. To truly understand the present, however, we must also understand the past and the changes that have led us to the present. Several European countries and regions have, therefore, created GISes of their changing administrative boundaries as a first stage in fully understanding the spatial and temporal complexities of long-term socio-economic change. Many others have plans to do so. In June 2000 a European Science Foundation funded workshop was held in Florence organised by Drs H Southall, M Goerke, and G Thorvaldsen. The meeting’s title was “Mapping Europe’s historic boundaries and borders: An exploratory workshop” (Southall et al. 2000). The meeting included a session on “Constructing historic boundary GISes” in which representatives of projects from various countries and regions reported on how their project had approached the problem of creating time-variant GISes of changing socio-economic units. This paper examines the different approaches to creating temporal GISes that are described in the literature and compares this to the actual methods used by these European projects.

The Great Britain Historical GIS Project: From Maps to Changing Human Geography

Abstract A major project is building a specifically historical Geographical Information System (GIS) for Britain, mapping the evolving human geography of the past two centuries. This system combines the changing boundaries of administrative units with a large database of historical statistics. This paper focuses on England and Wales, where work is most advanced, and examines the sources for the mapping work, how the GIS is built, the uses of the GIS to map past geographies, and the potential for using mid-nineteenth-century boundaries for mapping much earlier sources including the Domesday Book.

Comparisons between geographies of mortality and deprivation from the 1900s and 2001: spatial analysis of census and mortality statistics.

Objectives To examine the geographical relation between mortality and deprivation in England and Wales at the start of the 20th and 21st centuries. To explore the evidence for a strengthening or weakening of this relation over the century and test for relations between the mortality and deprivation patterns of a century ago and modern mortality and causes of death. Design Census and mortality data for 634 districts from the 1900s directly compared with interpolated ward level data from 2001. Setting Census data and national statistics for England and Wales in the 1900s and 2001. Population Entire population in both periods. Main outcome measures Standardised mortality ratios for all districts for both periods with additional cause specific ratios calculated for 2001. Deprivation (Carstairs) scores for each district in 2001, with comparable measure created for the 1900s. Correlations and partial correlations between deprivation scores and standardised mortality ratios in the 1900s and 2001 for the 614 districts for which all data were available. Results The was no evidence of a significant change in the strength of the relation between deprivation and mortality between the start and end of the 20th century. Modern patterns of mortality and deprivation remain closely related to the patterns of a century ago. Even after adjustment for modern deprivation, standardised mortality ratios from the 1900s show a significant correlation with modern mortality and most modern causes of death. Conversely, however, there was no significant relation between deprivation in the 1900s and modern mortality for most causes of death after adjustment for modern deprivation. Conclusions Despite all the medical, public health, social, economic, and political changes over the 20th century, patterns of poverty and mortality and the relations between them remain firmly entrenched. There is a strong relation between the mortality levels of a century ago and those of today. This goes beyond what would have been expected from the continuing relation between deprivation and mortality and holds true for most major modern causes of death.

Different Places, Different Stories: Infant Mortality Decline in England and Wales, 1851–1911

This article presents a substantive analysis using the Great Britain Historical Geographical Information System (GIS), one of the earliest national historical GISs. It develops exploratory techniques to explore local patterns of demographic change and applies these to the study of infant mortality in England and Wales from 1851 to 1911. The techniques developed could be applied to a wide variety of fields where the aim is to explore long-term spatio-temporal change using data published for administrative units that are affected by boundary changes. The Victorian and Edwardian eras saw the origins of the sustained infant mortality decline that characterized the entire twentieth century. Although the period has been extensively studied for a century and more, our knowledge of this vital phase is still surprisingly limited. In particular, much of the research to date has focused on urban areas and has thus stressed urban explanations as to why infant mortality began to decline. Because this article uses a comprehensive GIS database, we are able to challenge some of the orthodoxies that have emerged. It reveals that patterns of infant mortality decline in different parts of the country were more complex than has previously been described. Far from the national rate being driven by changes in urban areas, the largest declines and earliest declines in infant mortality were found in rural parts of the southeast of England, as the rural periphery lagged far behind. Urban areas were slow to decline due to the specific conditions that existed in them in this period.

Error‐sensitive historical GIS: Identifying areal interpolation errors in time‐series data

Historical GIS has the potential to re‐invigorate our use of statistics from historical censuses and related sources. In particular, areal interpolation can be used to create long‐run time‐series of spatially detailed data that will enable us to enhance significantly our understanding of geographical change over periods of a century or more. The difficulty with areal interpolation, however, is that the data that it generates are estimates which will inevitably contain some error. This paper describes a technique that allows the automated identification of possible errors at the level of the individual data values.

Geographical Information and historical research: Current progress and future directions.

To a greater or lesser extent, all historians make use of geographical information. This means that there is clearly a large potential for the use of Geographical Information Systems (GIS) in the discipline. GIS has its origins in the earth sciences and its approach and the way that it models the world is based on the traditions and requirements of these subjects. This means that while there are many advantages to using GIS in historical research, its use must be implemented with caution, based on the limitations of the data and the traditions of historical scholarship. In this paper we define GIS and explain why it is relevant to historical research. We then use a wide variety of examples to illustrate the ways in which historians have used GIS. Finally, we discuss how GIS needs to be improved to make it more applicable to historical research. Our aim is to demonstrate that GIS, if properly used, is not only applicable to the more quantitative, scientific historical paradigms, but is equally appropriate in the more humanities-driven, qualitative areas of the discipline.

A century of inequality in England and Wales using standardized geographical units

This paper analyses geographical trends in relative poverty in England and Wales over the last century by comparing key quantitative indicators from key dates. The comparison is made possible by interpolating all the datasets onto a single standardized geography. Results suggest rising inequality in spite of the decline in absolute poverty.

Analyzing Spatiotemporal Change by Use of National Historical Geographical Information Systems: Population Change during and after the Great Irish Famine

Several countries have made large investments in building historical Geographical Information Systems (GIS) databases containing census and other quantitative statistics over long periods of time. Making good use of these databases requires approaches that explore spatial and temporal change. The authors use a variety of visualization and spatial analysis techniques to explore population change in Ireland during and after the Great Famine of the late 1840s. Importantly, the techniques allow differences over space and time to be explored, thus stressing the diversity between places, rather than making all places appear the same, a common criticism of many statistical approaches. The authors demonstrate the potential of these techniques to explore geographical and temporal variations in large quantitative GIS datasets.

Spatial History: Railways, Uneven Development, and Population Change in France and Great Britain, 1850-1914

A comparative spatial history combining historical narrative, geographical thinking, and spatial analysis of historical data offers new perspectives on railway expansion and its effects in France and Great Britain during the long nineteenth century. Accessible rail transport in the rural regions of both countries opened new economic opportunities in agriculture, extractive industries, and service trades, helping to revitalize rural communities and decrease their rates of out-migration. In France, long-standing economic disparities between the developed north and the less-productive south gradually reduced. These conclusions are based, in part, on the use of historical geographical information systems (hgis) and spatial statistics, illustrating a component of spatial history.