The near ground measurements show strong variation of rain structure for all rain rates.
Variations of drain tile discharge and drain water salinity are also very dynamic as they respond to individual rain events.
For the other four regions, where time of persistence was almost always the full 30 years of the simulation runs, I compared the coefficient of variation of annual rain volume, longest wet period, and peak shoot mass using an ANCOVA to test how changes in rain pattern affected environmental and production variability.
I compared the effects of DMR and MAP on the coefficients of variation of annual rain volume (CVR), longest wet period (CVLWP), and peak shoot mass (CVmass) because greater environmental and population variability is theoretically related to shorter persistence [ 35, 36].
But, in the background, was something beyond the bounds of seasonal variation: the prolonged lack of rain affecting the Midlands, East Anglia, and the South.
These two aspects explain why variations in hydrochemistry caused by rapid infiltration of rain or surface water are much smaller compared to cave rivers.
And to their great credit, they allowed Pittsburgh to play itself, a picturesque late-19th-century city of red brick factories and dark, wainscoted interiors, whose weather seems to consist of variations on snow, rain and wind.
Drought is brought about by a shortage of rain or by a large variation in the amount of rainfall, and is the major abiotic stress limiting crop productivity worldwide (Saini and Westgate 2000).
But, the coefficient of variations has been relatively small and implying that constant amount of rain comes for most of the times during summer.
15 shows the variation of S with rain duration (t).
