Retencja wody w zróżnicowanych geograficznie zlewniach górskich

The article describes the research on the retention capacity of two mountain catchments in the Polish Carpathian Mts. These are the catchments of the Czarna Woda and Biała Woda streams. These catchments are adjacent, have a similar area (about 11 km2 each), but are geographically diverse. Their geomorphology, hydrographic network, soil water permeability and land use were analyzed. The Czarna Woda catchment is a forest catchment, and the Biała Woda catchment is a forest and agricultural catchment with pasture areas. The geographical analysis of the catchment showed that the Czarna Woda catchment most likely has greater retention capacity. Theoretical analyzes were verified on the basis of long-term measurements of flows in both streams. Outflows were calculated for the entire study period (2006-2022), as well as annual, monthly and daily outflows. The measurements were carried out using the overflow method in permanent measurement cross-sections. The total outflow from both catchments was simi-lar, so they had similar water resources. In particular years, months and days, outflow often differed significantly between catchments. It was found that during the periods of increased water runoff (from precipitation, from snowmelt) the outflow from the Biała Woda catchment was higher, while in the periods without precipitation the outflow from the Czarna Woda catchment prevailed. Short-term flood outflows were at least several dozen percent higher in the Biała Woda catchment. The measurement data confirmed that water was better retained in the Czarna Woda catchment and the outflow was slower. Water retention processes in the Czarna Woda catchment allowed to maintain minimum outflows at a level several times higher than in the Biała Woda catchment. The studies have shown that in a very small mountain area there can be a large variation in outflow in individual streams. Retention capacity of the catchment depends on environmental conditions and human activity.