Comparison of parameters influencing the behavior of concentration of nitrates and phosphates during different extreme rainfall-runoff events in small watersheds

Abstract. The behavior of solute concentrations during storm events is completely different from their behaviour under normal conditions, and very often results in hysteresis. This study aim is to explore the relationship between the biogeochemical and hydrological parameters describing natural conditions and the reciprocal interactions between changes in concentration of selected indicators of water quality in water and the discharge dynamics during different types of extreme rainfall-runoff events in the Jenínský stream and the Kopaninský stream catchment (Czech Republic). The relationship between concentrations and runoffs is explained by concentration-discharge hysteretic loops. As the statistical method used for cross analyzing the impact of the parameters there was chosen the RDA analysis. The relationships between the particular parameters were examined separately by conditions of spring snow melt and summer storm events. The results than confirmed the very strong relationship between parameters describing water quality and percentage of stable parts of the catchment and also of infiltration vulnerable sites.