R
Seminar Notice
Title: Modeling Nitrates in the Des Moines River
This seminar takes the form of a `progress report' on development of
a simple statistical structure with which to model concentrations of
nitrate/nitrite at 7 monitoring stations on the Des Moines River.
The overall goal of the analysis is to develop a model with few
parameters that is capable of describing nitrate concentrations in
the enitre monitoring network using data (provided by the US Army
Corps of Engineers) of roughly biweekly observations over the period
1982 to 1996. A subset of these data, consisting of 938 observations
from 1982 to 1985 is used as the primary focus for model development.
A conditionally specified Gaussian model is used, with
dependence conceptualized as a temporally-varying
spatial phenomenon. While any of a number of approaches might yield
adequate model structures for this problem, the approach taken
focuses on maintaining a simple description of large-scale structure
over time and incorporating the majority of variation within the
dependence structure.