Abstract:
Floods are short-term, unexpected and frequently unpredictable. A flood is not a local phenomenon but can happen everywhere. Accidents play a major role in the formation of flood size and flood frequency on each object. High floods usually result from a combination of several factors, when laws of the theory of catastrophes come into effect. This complicates forecasting and increases the factor of risk. While numerous attempts have been made to use satellite surveys for mapping of inundation they have not produced reliable material for the estimation of the danger of occurrence and the development of floods. The reason lies in inherent features of the investigated process and in the kind of information used. It is necessary to learn how to use the latter in an optimum combination. In Russia there is a twenty years experience in the thematic analysis of satellite images. The technique of estimating the river flood-plain submersion has been developed using medium resolution data from operational satellites besides aerial and satellite photographs. For the Obi and Volga river reference data (volume of water and inundated area at any water stage)for their flood- plains are prepared. The typical layouts of floodings are revealed.