Non-stationary variance models for nitrous oxide emissions from soil, by spectral tempering

 

Host Institution:

La Trobe University

Title of Seminar:

Non-stationary variance models for nitrous oxide emissions from soil, by spectral tempering

Speaker's Name:

Dr Kathy Haskard

Speaker's Institution:

Australian Mathematical Sciences Institute

Time and Date:

Friday 15 October 2010 at 11:00 am

Seminar Abstract:

 

In geostatistical spatial modelling, data are typically assumed to have stationary covariance -- because with only a single realisation of a random process it is difficult to estimate a covariance model that is different at different locations. However this assumption can be untenable in varied landscapes, and estimates of the variance of predictions can be badly affected.

This is important, for example, in assessing climate change scenarios. Spectral tempering allows flexible spatial adaptation of spatial covariance; smoothness and variances can be adapted independently, with parameters that are simple and interpretable. This talk begins with an introduction to some geostatistical concepts, then describes spectral tempering in a graphical way, illustrating and validating with application to data on soil emissions of nitrous oxide, an important greenhouse gas. The method can be applied to many kinds of spatially-correlated data.

 

Kathy Haskard has over 20 years' experience in statistical consulting, largely in agricultural and biological areas, for university and government research organisations in Adelaide, Canberra and Hobart. She also has research experience in spatial analysis (model-based geostatistics), exploring the Matérn correlation function and anisotropy, and has recently completed a posting at Rothamsted Research in the United Kingdom, developing a method for fitting non-stationary spatial covariance models.

Kathy is currently working as a statistician for AMSI, the Australian Mathematical Sciences Institute, providing advice and assistance with statistical aspects of AMSI's work, including consulting work with Parks Victoria and supporting the internship program.

 

Seminar Convenor:

This email address is being protected from spambots. You need JavaScript enabled to view it.

AGR IT support:

This email address is being protected from spambots. You need JavaScript enabled to view it.