Measuring and Sampling Surface Runoff and Subsurface Drain Outflow Volume

An instrumentation system for automatically measuring and sampling surface runoff and subsurface drain outflow from experimental plots was developed. Surface runoff and subsurface drain outflow were channeled to a central collection building where volumes were measured and recorded by datalogger. The data stored in the datalogger were automatically transmitted to an IBM-compatible computer at Harrow Research Station every 24 h. Laboratory calibration and field verification of the system showed excellent agreement between actual and measured volume. The digital output from the water-measuring device was used to activate a water sampler at selected volumes.