Presentation on theme: "Claire Ferguson 1, Adrian Bowman 1, Marian Scott 1 and Laurence Carvalho 2 1 University of Glasgow 2 Centre for Ecology & Hydrology A Case Study of Loch."— Presentation transcript:
Claire Ferguson 1, Adrian Bowman 1, Marian Scott 1 and Laurence Carvalho 2 1 University of Glasgow 2 Centre for Ecology & Hydrology A Case Study of Loch Leven http://www.tulbol.demon.co.uk/art/banatvewe.jpg Regression Case Study Additive and Varying-Coefficient Models
Dataset: 1968 - 2002 150 variables measured, covering… Physics Lake chemistry Lake biology Weather Loch Leven (LL)
The EC Water Framework Directive (WFD) 2000 states that there should be good status in all shallow waters by 2016. Research: Investigating statistical techniques to explore the combined impacts of climate and nutrients on water quality. Motivation
chlorophyll a Response year, month, SRP, Daphnia, water temp, NO 3 -N Covariates Additive Model 1988 - 2002
Mainly linear relationships between variables. Little evidence of trend and seasonality. Important ecological relationships identified. The nature of trends and relationships can be explored simultaneously. For chlorophyll a (in this time period)- Summary of Additive Models
Linear Regression Model Varying-coefficient Model (VCM) Varying-coefficient Model m = month Do relationships change throughout the year?