The present page is a description of a class project in Dr. Donovan's Quantitative statistics in R, at West Virginia University.
Title: Sensitivity Analysis using R: Applying Roderick and Farquhar, 2011 to a Reference Catchment. Abstract
A sensitivity analysis was carried out in order to understand the variations on runoff due to variation in climate conditions at the reference catchment "Watershed 4" (WS4) part of the Fernow Experimental Forest in WV. The investigation follows the theoretical framework and methodology laid out by Roderick and Farquhar, 2011. Roderick and Farquhar analysed long term averages of hydrological variables from the Murray-Darling Basin in Australia, to understand the relationships between the variability in climatic variables (water atmospheric demand and precipitation) and the variability landscape changes to the variability in runoff production. An important contribution from their work was the calculation of sensitivity coefficients that have been derived from the well-known Budyko Equation. The Budyko Equation is a simple hydrologic models that allows to partition Precipitation into Evapotranspiration and Runoff for long term averages in a watershed. In the present investigation, the named sensitivity coefficients are used in a small head water catchment. The main results show that the runoff in WS4 is more sensitive to changes in P than to changes in Potential Evapotranspiration.
Data The data that I used can be found at https://www.fs.usda.gov. The USFS has a database where you can find information for different watershed in the US including the watersheds at the Fernow Experimental Forest.
Time series of Precipitation, Runoff, Temperature average, Temperature maximun and Temperature minimun from 1952 until 2013 for Watershed 4 were used in this analysis. Other time series from other catchments should also work using this approach.
Dr. Rodrigo Fernandez Reinoza and Dr. Nicolas Zegre introduced me into this approach and have help me solve most of the theoretical questions I have had about the Budyko framework and Roderick and Farquhar 's approach.
References: Roderick, M. L., and G. D. Farquhar (2011), A simple framework for relating variations in runoff to variations in climatic conditions and catchment #properties, Water Resour. Res., 47, W00G07, doi:10.1029/2010WR009826.