Cookies

We use cookies to ensure that we give you the best experience on our website. You can change your cookie settings at any time. Otherwise, we'll assume you're OK to continue.

Department of Mathematical Sciences

Seminar Archives

On this page you can find information about seminars in this and previous academic years, where available on the database.

Statistics Seminars: Model-based geostatistics, preferential sampling and environmental monitoring

Presented by Peter Diggle, Department of Medicine, Lancaster University and Department of Biostatistics, Johns Hopkins University

5 February 2008 14:15 in CM221

Geostatistics is the branch of spatial statistics whose purpose is to make inferences about a spatially continuous phenomenon using spatially discrete data. Classical geostatistical methods were developed, principally at Ecole des Mines, Fontainebleau, independently of mainstream spatial statistics. The term model-based geostatistics was coined by Diggle, Moyeed and Tawn (1998) to refer to geostatistical analysis based on general statistical principles applied to an explicitly declared stochastic model; see also Diggle and Ribeiro (2007).

Preferential sampling refers to situations in which measurements of a spatial phenomenon are made at locations chosen by a mechanism that is stochastically dependent on the underlying phenomenon itself.

Preferential sampling appears to be widespread in practice, although it is often ignored. Environmental monitoring is a case in point, monitors often being placed near suspected pollution sources.

In this talk I will first review model-based geostatistical methods in the context of an application to tropical disease risk mapping (Diggle et al, 2007). I will then discuss how preferential sampling invalidates standard geostatistical methods and suggest possible remedies. Finally, I will describe an application to environmental monitoring data concerning heavy metal bio-monitoring in Galicia, Spain (Diggle, Menezes and Su, 2007).

Diggle, P.J. Moyeed, R.A. and Tawn, J.A. (1998). Model-based geostatistics (with Discussion). Applied Statistics, 47, 299-350.

Diggle, P.J. and Ribeiro, P.J. (2007). Model-based Geostatistics. New York: Springer.

Diggle, P.J., Thomson, M.C., Christensen, O.F., Rowlingson, B., Obsomer, V., Gardon, J., Wanji, S., Takougang, I., Enyong, P.,Kamgno, J., Remme, H., Boussinesq, M. and Molyneux, D.H. (2007). Spatial modelling and prediction of Loa loa risk: decision making under uncertainty. Annals of Tropical Medicine and Parasitology, 101, 499-509.

Diggle, P.J., Menezes, R. and Su, T-L. (2008). Geostatistical analysis under preferential sampling. (submitted)

Contact sunil.chhita@durham.ac.uk for more information