Zmienność przepływów niżówkowych w wybranych zlewniach pogórskich i beskidzkich w latach 1988‑2017 = Variability of low flow in Polish Carpathians (foothills and Beskidy Mountains) catchments in the period 1988‑2017

Abstract

Water flow in the Polish Carpathians was exemplified by long-term (1988‑2017) analysis of two foothill catchments (of the Skawinka and Stobnica) and two catchments in the Beskidy Mountains (of the Soła and Osława). The work allowed for the determination of the duration of low flows and outflow deficits in relation to changes in thermal and precipitation conditions, as well as land use and land cover. In the selected catchments, the 30-year period brought a decrease in the area of arable land and an increase in the area of grassland and forest. In addition built-up areas increased by 495% between 1990 and 2018. A greater susceptibility to the occurrence of total drought was noted for the Beskidy Mountains catchments, in which the duration of low flows and outflow deficit was greater than in the foothill catchments. At the same time, the mountain catchments proved less susceptible to the emergence of deep drought, on account of their higher levels of forest cover and levels of soil permeability. In regional terms, the durations of low flows and outflow deficits were greater in the catchments located in the eastern part of the Carpathians (those of the Stobnica and Osława), in line with this area’s intensified features of a continental climate.