On the accuracy of areal rainfall estimation: A case study

Abstract

The issue of the accuracy of areal rainfall estimation is discussed through a case study on a catchment area in the Cévennes region of France. The basic tool for the analysis is a “scaled estimation error variance” which is computed from a scaled climatological variogram model of the rainfall field. We show how this variance provides a theoretical criterion to compare the accuracy that can be expected with three linear estimators (Thiessen, spline, and kriging) for various networks' densities. To support the methodology an experimental validation of the scaled estimation error variance computation is performed, using “reference” areal rainfall values computed with a very high density network.