Small-Scale Rainfall Variability in Western Puerto Rico and its Implications on Agricultural Water Management Eric Harmsen, Professor Dept. of Agricultural and Biosystems Engineering, University of Puerto Rico, Mayagüez JarekCintron Department of Industrial Engineering, UPRM, firstname.lastname@example.org EdvierCabassa Department of Electrical and Computer Engineering, UPRM, email@example.com
Situation • Rain gauges are the most common means for farmers to determine whether their crops have received sufficient water, and whether supplemental irrigation is needed. • Farmers commonly rely on rainfall information from a single rain gauge on their farm or from a rain gauge located off the farm. • Similarly, university researchers commonly rely on rainfall information from the single rain gauge located on the experimental station.
But how reliable is rainfall information from a single gauge located, in some cases, several kilometers from a field? • To help answer this question, a rainfall variability study was conducted near the University of Puerto Rico-Mayagüez Campus in Western Puerto Rico.
Approach • Twenty-eight rain gauges were installed within a 4 km x 4 km area. Rainfall amounts were measured every 5 minutes between August 2006 and August 2007.
Equipment Watchdog Rain Gauge Watchdog Shuttle
Results • For the 62 storms evaluated, the average storm rainfall, standard deviation, and minimum and maximum rainfall were 15.94 mm, 11.87 mm, 30.14 mm and 4.53 mm, respectively. • For any single storm the statistics can be more striking, for example, May 24th, 2007, the average storm rainfall, standard deviation, and minimum and maximum rainfall were 55.4 mm, 30.74 mm, 129.4 mm and 28.2 mm, respectively.