Recently, I’ve been playing with patterns of drought in paleo records of streamflow. One of the earliest and most helpful tools I’ve developed, identifies and characterizes droughts in extremely long time series using R. I’m still hacking my way through it, but this is what has been cooking thus far… For this example I’ll be 


Zero Inflated Models and Generalized Linear Mixed Models with R.
Zuur, Saveliev, Ieno (2012).