INFORMATION THEORETICAL APPROACH TO COMPARATIVE-STUDY OF LAKES

Information theoretical indices (K, M, I), introduced in a previous paper, are used for characterization and comparison of various types of lakes studied by IBP in Japan. The index K is a measure of distribution of matter among compartments in a system as compared with a reference system, the index M is a measure of concentration of matter in a system as compared with a reference system, and I = K + M. These indices are calculated for each lake; and the value M vs. K, the effect of changing reference system, the effect of aggregation of compartments, and the relation to nitrogen and phosphorus concentrations in lake water are investigated. The value of M becomes larger as eutrophication progresses. The value of K also increases with eutrophication with a large rate for oligo-mesotrophic lakes and with a small rate for eutrophic lakes.