Wody gruntowe w dorzeczu Soły

Abstract

In the basin of the Soła R. the lay of the land does not favour the accumulation of underground water in any larger amount. In the mountain region the large accurrence of shales in the subsoil and of clayey covers, combined with the steep slopes, facilitates sterile water outflow. A role of some significanse is played by the thicker colluvia in large source-made funnels as well as by the fairly developed lower-slope covers in the upper basin. In the dales and larger valleys relevant are the terrace sediments containing outstanding amounts of gubsoil water. These, however, are restricted by the not too thick water-bearing sediments, and by the strong drainage at the time when the fluvial water mirror is low. A different type of water in the alluvial fans does not play any major part either, because of its thin water-bearing levels, mostly made of gravel covered with a thick layer of clay. In the dry seasons (as, e. g., in the Autumn 1959) there occurs a distinct lowering of subsoil water mirror in all geological environments. Within the alluvial fans, in low terraces, on narrow watersheds, and on some summit planes (the basins of the Ujsółka, Łękawka, and other rivers) water tends to be scant, and sometimes deficient. The irregular and often violent course of atmospheric precipitation, intersified in the deep valleys closed from the south, contributes towards erosion and the related phenomenon of subsoil drainage, as well as to a great outflow. The deep and dense cutting of the mountain part of the basin makes alimentation of subsoil water difficult. More important for our purposes is the lower basin of the Soła, where in Quaternary measures largely interspersed with gravels, subsoil water is collecting. It is fed mainly with precipitation. In the submontane region adjoining the Beskid Mały Range feeding takes place through the covers of damp mountain slopes absorbing large amounts of water, as the northern slopes of the Beekid get particularly much precipitation in Summer as a result of the rain- bearing waves which tend to bank up there.