Original paper

Water circulation and chemical denudation in the upper Skawica River ?ysch catchment, Western Carpathian Mountains

Łajczak, Adam

Abstract

The paper characterizes subsurface water circulation on the slopes of the upper Skawica River catchment in the Western Outer Carpathians in Poland that includes deep translational and rotational landslides. The catchment is located in the highest part of the flysch Carpathians, with elevations up to 1,725 m. Abundant water resources and relatively deep circulation foster subsurface dissolution of flysch strata, enabling the formation of deep landslides and increased groundwater penetration in interbedded marly shale and sandstone. The purpose of this paper is to describe water circulation based on an analysis of spring water temperature, chemistry, discharge, and to estimate the amount of chemical denudation in the upper Skawica catchment by calculating the outflow of dissolved solids by springs. The methods used in the research included repeated measurements of spring discharge, temperature, and quantity of dissolved solids produced by selected springs in the catchment. The discharge of dissolved solids by springs varies with elevation, with differences also being observed between cuesta-type slopes and slopes following the dip of the local strata. The largest rates of discharge of dissolved solids were measured between 900 and 1,300 m of elevation (4,2 00 - 5,500 mg · s-1 · km-2), where the thickest colluvium recharging numerous large springs occurs. Chemical denudation on cuesta slopes leads to sharpening of existing geomorphic contrasts, while slopes following the dip of bedrock strata become gentler and smoother. It has been shown that chemical denudation of the upper Skawica flysch region, which locally reaches 150 tons · yr-1 · km-2, is more dependent on groundwater resources than on bedrock lithology. A characteristic feature of the catchment in question is the more pronounced (versus other flysch mountains) influence of distant and relatively deep water circulation in colluvia and fractured rocks upon dissolution of the bedrock.

Keywords

babia gÓra massifwestern outer carpathianschemical denudationflysch springslandslide gÓra massifwestern outer carpathianschemical denudationflspringslandslide morphologysubsurface water circulation subsurface water circulation