Spatial relationship between hydrodynamic and physico-chemical parameters of surface water for a basin with shale rock series as an indicator of intensity and direction of chemical denudation in the Western Carpathians

Abstract. Hydrochemical evaluation of stream quality in the Western Carpathians requires a system approach, gradually excluding factors less or more responsible for washing, mixing contaminants and their farther transportation in the stream channel. In this work, the spatial autoregression model was used to estimate the relationship between hydrodynamic and physico-chemical parameters of surface water in various groups and variants of basin use. The highest mean shear stress was 0.178 N⋅m² in forest surface water. The highest mean Reynolds number (23654) was recorded in the stream channel at permanent grassland, and the lowest number (0.426) at arable lands. Analysis of spatial autoregression to a high degree showed space-time relations in various measurement points. The turbulent diffusion coefficient should be regarded in the space-physical model, constructed based on the influence of hydrodynamic indicators on the shaping of physico-chemical parameters in the flysch basin. The autoregression confirmed that the turbulent diffusion coefficient played a high role for ions K⁺ and P-PO₄³⁻ in surface water at arable lands and for cation K+, as well as total iron for grassland (p < 0.05). A relation for physico-chemical was not found for surface water in forests. The results, to a high degree, will be used to createan erosion model concerning the alimentation of alluvial deposits from weathered Carpathian flysch or surface wash depending on the material delivery in a basin.