An Analysis of Observed Changes in the Surface Water Budget in Baton Rouge, Louisiana

The historical hydroclimatology of Baton Rouge was examined using estimates of annual runoff from the Thornthwaite water balance model. The model was tested to determine its sensitivity to natural variability of mean monthly temperature, monthly potential evapotranspiration and monthly total precipitation. The Thornthwaite water balance model was used to generate a times series of annual runoff estimates for Baton Rouge from 1895 to 2010 and linear regression was applied to the time series to search for trends. The results indicate the Thornthwaite water balance model is extremely sensitive to changes in precipitation. Contrary to the findings of similar studies, no significant trend was found in annual runoff for Baton Rouge over the historical record.