Herbicides in Metro Atlanta Streams and Rivers

Data Analysis

Cristal Moon

Rivers

Suwanee Creek

Nickajack Creek

Chattahoochee River

Questions• Do herbicide levels have yearly trends?• Are they related to other factors in surface

water?

Variability of two Pesticides in Chattahoochee

Levels for Nickajack Creek

Levels for Suwanee Creek

Least Squares Regression

+ is levels, green line is regression, red bars are 95% confidence levels

Error variance=0.3095Correlation Coefficient= 0.1375P-value=0.1814

Error variance=0.0089Correlation Coefficient= 0.1681P-value=0.1016

Normal?

Chi2=4,337,300Chi2inv=118.7516Chi2>Chi2inv, therefore distribution is not normal

Chi2= 527.3569, Chi2inv=118.7516Chi2>Chi2inv, therefore distribution is not normal

Discharge vs. Herbicides

Correlation Coefficient: 0.0374P-value=0.7174

Correlation Coefficient: -0.0133P-value= 0.8974

Specific Conductance vs. Herbicides

Correlation Coefficient= -0.1757P-value= 0.0868

Correlation Coefficient= -0.2161P-value= 0.0344

pH

Correlation Coefficient= 0.0063P-value= 0.9515

Correlation Coefficient=-0.0919P-value= 0.3732

Principle Component Regression

Green is Least-Squares, Blue is Reduced Major Axis, Black is PCR

LSSA

Significant frequencies (in Hz) at 0.97765Corresponding powers: 16.0276

Significant frequencies (in Hz) at 0.97765Corresponding powers: 8.7976

Conclusions

• Annual increase in herbicides early in year• Linear increase over time• Levels not related to pH or discharge• Specific Conductance somewhat correlated