NOTE ON SAMPLING ERRORS IN THE RAINFALL AND RUNOFF DATA COLLECTED USING TIPPING BUCKET TECHNOLOGY

Data precision for rainfall intensity and runoff rate using tipping bu cket technology is controlled by the bucket volume, V, the catchment a rea, A, and the sampling interval, t. The maximum absolute error is le ss than V(A Delta t)(-1) and the standard error is given by V(root (6) over bar A Delta t)(-1), both of which are independent of the magnitu de of rainfall intensity and runoff rate being measured. Therefore, th e relative error cart be quite large during events with low rainfall i ntensity or runoff rate. The magnitude of the sampling error given abo ve can be used to assist in experiment and equipment design and in dat a analysis.