DETERMINATION OF BASIN LAG TIME IN RAINFALL-RUNOFF INVESTIGATIONS

Basin lag time varies not only between basins but also within a basin. To explain this variation, the basin lag time was hypothesized as a f unction of the ratio of the channel length from the centroid to the ou tlet of the basin, divided by the velocity of flow at the gauging site at the time of passage of peak discharge. The records of six basins w ere used to test this hypothesis. The results are not incompatible wit h this hypothesis.