EN
The author attempts a qualitative estimation of the matter delivery from basins to lakes on the basis of physical geographic parameters of the basin and hydrological features of the reservoirs. The analysis was made for 40 lake basins situated in the Iława, Chełmno-Dobrzyń and Mazurian Lakes Districts that represent an early glacial landscape (Fig. 1). The following features of the physical geographic environment are coinsidered to have an impact on the matter delivery to the basin: size of the lake basin, morphometry of the basin, drainage density, geological structure and soil conditions and methods of land use. The growth of the lake trophism depends on hydrological features of the basin itself, which may be the following: lake index, Shindler's index, type of the lake according to its water balance, and intensity of water exchange in the lake. The estimation of the effect of physical geographic environment on the matter delivery to the lake was based on the evaluation of features, carried out in such a way that the intensity of the analyzed process was evaluated on the scale 1-3 points, where 0 was a limited impact on the releasing of the area discharge, 1 - small influence, 2 - medium influence, 3 - great influence on the matter delivery to the lake. The final estimation consisted of the average of points from the summing of the evaluated features. Land use and lake index were ascribed double value, whereas the remaining features, i.e. morphometry of the basin, lithology of surface formations, Schindler's index, balance type of the lake and intensity of water exchange in the lake, were marked 1. Thus, four groups of lake basins of different degree of effect of physical geogriaphical environment on the releasing of biogenous matter were received (Table 9). Group one consists of the basins of limited capacity of the matter delivery to the lake (below 1.0), Group two consists of the lake basins of small capacity of the matter delivery to the lake (1.0-1.4). The third group includes basins that bear a considerable impact on the lake (1.5-1.9), and the fourth group comprises: baisins of great capacity of the matter delivery to lakes (above 1.9).