This study presents a centroid-based method of regional analysis employing the Kriging technique. A case study in streamflow estimation using Kriging was carried out in the Choushui Chi Basin in central Taiwan. A variable (runoff depth) distributed in space was viewed as a regionalized variable, and the representative value of the runoff depth was allocated on the centroid of the area considered. The results show that the spatial structure of the measurements in the experimental variogram is not purely random and the stationarity hypothesis is appropriate in estimating streamflow. ¿ 1998 American Geophysical Union