Sylvie Dubuc | University of Oxford (original) (raw)

Papers by Sylvie Dubuc

Encyclopedia of Migration, 2014

CyberGeo

ABSTRACT Location analysis has become ‘intrinsically linked with GIS-based analysis and modelling... more ABSTRACT Location analysis has become ‘intrinsically linked with GIS-based analysis and modelling.’ Optimal location models are often used for decision making to locate facilities to maximise access to clients/demand within a defined continuous area of possibilities. But what happens if the potential location of demand is spatially confined and best location model is applied to choose between different stationary facility sites? This is a question concerning the mining industry in the UK, who wants to restore exhausted quarries (facilities) into energy-crop fields. A small number of quarries have to be selected within a larger panel of potential quarries sites to be restored. These selected quarries have vocation to supply a power station with energy-crop. We defined the quarries of best location to be converted into energy crops supplier sites by minimising the transport costs (required criteria) of crops to a power station. We derived transport cost from distance measurements and time of travel. Therefore, the objective function of the model minimized the demand distance/time of travel (expressing transport cost) between the demand node (Power station) and the nearest quarry(ies). Based on the shortest path distance criteria, the demand of crops required for the power station was allocated to the quarries until the demand was satisfied. Doing so, the cluster of quarries of best location (minimum distance/time) to be restored in energy-crop fields was identified in order to minimize the transport cost.Several ways to assess the time of travel between quarries and power site were explored and tested in the model of quarries selection. Much attention was given to measuring accessibility. First, based on metric distance the length of roads was used to find the least cost path. Multi-criteria distance-time measures were computed according to the length of the road, the travel speed according to the type of road, the gradient slope of the road derived from a Digital Elevation Model (DEM) values and the ‘slow down effect’ of urban areas. The results of the different routing processes were compared. Our findings underline the use of multi-criteria travel time calculations in order to improve accuracy of accessibility and location models. The method was tested on a sample area in the North of England and could be extended and applied to the entire UK with some accommodations. This is presented as part of the methodology and discussed in the conclusion.

L'Espace géographique

Si une certaine revitalisation des zones rurales se confirme, après plus d'un siècle d'ex... more Si une certaine revitalisation des zones rurales se confirme, après plus d'un siècle d'exode, elle semble toujours exclure de vastes espaces peu peuplés et éloignés des grandes villes. Le maintien du peuplement dans ces zones "fragiles" est l'enjeu des politiques de développement. L'Aveyron et la Lozère, situés au sud du Massif central, dans la diagonale du vide, constituent un terrain d'étude privilégié pour cette question. On a élaboré une mesure multidimensionnelle qui permet d'évaluer le dynamisme à l'échelon local sur une période d'une vingtaine d'années. Cette mesure a été systématiquement corrélée avec de multiples indicateurs, dans le cadre d'une analyse comparative de près de 500 communes. Cette démarche a permis d'identifier les principaux facteurs explicatifs de l'inégal développement rural et de les hiérarchiser. L'inégal dynamisme rural s'explique avant tout par des facteurs de situation géographique rela...

A number of socio-economic and cultural factors potentially influence fertility across and within... more A number of socio-economic and cultural factors potentially influence fertility across and within countries, including ethnicity. However, apart from census data, little data is available, at least in the UK, to estimate fertility rates and thus fertil ity trends by ethnic groups between censuses. Previously, the Labour Force Survey (LFS) has been exploited to produce national total fertility rates (TFR)

Cybergeo, 2007

Ethnicity and Integration, 2010

Ethnic diversity of the contemporary UK population is reflected in fertility differences and this... more Ethnic diversity of the contemporary UK population is reflected in fertility differences and this chapter presents recent trends in the level and timing at childbearing of women of the various ethnic groups identified in the UK. Labour Force Survey data and recently refined Own Children method are used to produce improved fertility estimates using the most detailed ethnic classification available

Population Studies, 2010

This paper presents estimates of the level and trend of the fertility of different ethnic minorit... more This paper presents estimates of the level and trend of the fertility of different ethnic minorities in the UK from the 1960s up to 2006. The fertility estimates are derived primarily from the Labour Force Survey using the Own-Child method, with additional information from the General Household Survey and vital registration data. Comparisons are made between the level of fertility of UK-born and immigrant mothers from minority groups, and the fertility of the populations in the country of origin. Total fertility in all groups has fallen from levels that were initially relatively high. That of some UK ethnic groups has already fallen to about the level of the UK national average (e.g., black Caribbean) or below it (e.g., Indian and Chinese). Only among Pakistani and Bangladeshi women does total fertility remain substantially above the national average despite a continuous decrease over the last 20 years.

Population and Development Review, 2012

ABSTRACT The fertility of immigrants' children increasingly shapes the ethnic diversity o... more ABSTRACT The fertility of immigrants' children increasingly shapes the ethnic diversity of the population in Western Europe. However, few data are available on the fertility patterns of immigrants and their offspring. This article provides new fertility estimates of immigrants and immigrants' children by ethnic group in the United Kingdom that may provide betterinformed fertility assumptions for future population projection models. The impact of migration-specific tempo effects on the period TFR of immigrants is analyzed. Among the results, intergenerational fertility transitions strongly contribute both to fertility convergence between ethnic groups and to fertility "assimilation" or "intergenerational adaptation" to the UK mainstream childbearing behavior. Ethnic fertility convergence, particularly marked for populations originating from high-fertility countries, reflects in part decreasing fertility in sending countries and in part intergenerational adaptation to the UK mainstream. Higher educational enrollment of the daughters of immigrants may partly explain their relatively lower fertility.

Population and Development Review, 2007

Journal of Population Research, 2009

Fertility across and within countries is influenced by a number of socioeconomic and cultural fac... more Fertility across and within countries is influenced by a number of socioeconomic and cultural factors, including ethnicity and potentially religion. However, apart from census data, little information is available, at least in the UK, to estimate fertility rates and thus fertility trends by ethnic and religious groups between censuses. Previously, the Labour Force Survey (LFS) has been exploited to produce national total fertility rates (TFR) by ethnic groups up to 2001 using the reverse-survival Own-Children Method (OCM). Here the LFS-OCM is assessed and refined to improve accuracy and tested against official statistics. The LFS-OCM is compared with results obtained using more straightforward techniques based on Child-Woman Ratios using the same LFS data, and differences are discussed. The refined method is applied to produce recent fertility profiles by ethnic groups, including trends in the TFR and age-specific fertility rates, showing significant and decreasing differences between groups. Furthermore, the method allows us to reliably investigate TFR within one ethnic group by other criteria, as illustrated by differences in the TFR by religious affiliation of Indian women.