Optimal Estimation of the Average Areal Rainfall and Optimal Selection of Rain Gauge Locations

Abstract

We propose a simple procedure for the real‐time estimation of the average rainfall over a catchment area. The rainfall is modeled as a two‐dimensional random field. The average areal rainfall is computed by a linear unbiased minimum variance estimation method (kriging) which requires knowledge of the variogram of the random field. We propose a time‐varying estimator for the variogram which takes into account the influences of both the seasonal variations and the rainfall intensity. Our average areal rainfall estimator has been implemented in practice. We illustrate its application to real data in two river basins in Belgium. Finally, it is shown how the method can be used for the optimal selection of the rain gauge locations in a basin.