Use of Entropy in the Assessment of Uncertainty of River Runoff Regime in Poland

Abstract

The objective of this paper is to describe spatial differences in the uncertainty of features of the runoff regimes of Polish rivers based on entropy in Shannon's information theory. They included: the entropy of monthly river runoff and the entropy of river runoff distribution over time. An analysis of monthly flow series for the years 1951-2010 from 395 gauging stations located on 248 rivers in Poland was performed. This allowed a quantitative determination of the degree of uncertainty of two regime characteristics indirectly establishing the predictability, regularity, and stability of their appearance and their spatial variability. An analysis of relations between the calculated entropy, as well as between the entropy and the classical parameters commonly used was performed in describing the hydrological regime. The obtained grouping of rivers into four categories in terms of entropy of volume and distribution of runoff in the annual cycle clearly coincides with the types of river regime distinguished in Poland.