EN
The paper presents the results of research on water balance for Poland (the work was in IHP UNESCO programme). The undertakiing of the theme was the result of hydrological cooperation within the socialist countries. The subject of the study is the structure of the water balance studied in 381 basins, in the form of Lvovitsch's differential equation, for the period 1931-1960. The structure of the equation considers a corrected value of precipitation-the so-called real precipitation. Lvovitsch's equation includes six elements of water balance: precipitation (P), surface runoff (Hp), groundwater (Hg), land evaporation (E), the so-cold mean runoff and a basin areal moisture (W). The form of the equation is as follows: P = Hp+Hg+E where H = H p+H g The groundwater runoff, however together with land evaporation determines the basin areał moisture W: W = P-Hp = E+Hg In order to characterize the structure of the water balance for Poland, the dependence of evaporation and groundwater runoff upon the areal moisture was calculated by formula: KE= E/W and evaporation coefficient and groundwater runoff coefficient by the relations: Kg = Hg/W; KE = 1-Kg = E/W All the water balance elements together with additional characteristics were presented in the form of izopleths with equal intervals. Little notice was paid to temporal distribution of each element, however, their spatial distribution was carefully examined including all the most importand regional features of Kondracki's physico-geographical regionalization. The gradient curevs of the six elements of the water balance form the basis for determining the mean water balance of major drainage basins and areas. The new estimation of the water balance can be treated only as a statical one emphasizing also the relationship between its elements and their geographical distribution. It enables verification of the natural water balance for Poland and also is a new approach in cartographic synthesis of its elements. The obtained results refer to natural conditions, however, they (may be treated as) are the foundation for estimating the future changes of the country's water resources.