Impact of antropogenic activities on ecological status of the Meredský creek

The presented thesis deals with the evaluation of the ecological status of small watercourse Meredský creek situated in Central Bohemia. Meredský creek springs in the village of Záborná Lhota, runs through the village of Chotilsko and behind the village of Čím empties into the river Vltava. This creek is affected by the urbanization, in the catchment area there is continual livestock grazing and there are several bigger water areas and smaller ponds situated on the creek. The landscape is completed by the mixed and coniferous forests and meadows. The evaluation rate of the pollution was determined according to the selected physical and chemical indicators of the water quality directly in the flow or evaluated in the laboratory conditions, biological status was determined by the community of aquatic macroinvertebrates (saprobity index, ASPT index, BMWP score, Margalef´s diversity index) and hydromorpohological status (average status) was evaluated too. The final ecological status was evaluated according to the Czech State Standard 75 7221 and requirements given by the environmental quality standards. Concentrations of ammonia, total phosphorus, nitrates, chlorides, dissolved oxygen were accomplished as not meeting environmental quality standards. According to the saprobity index, ASPT index, BMWP score water quality is average. Meredský creek reached the 3rd Class of hydromorphological status. According to the chemical status final ecological status is established as not meeting the requirements of the environmental quality standards and general measures leading to the better ecological status are suggested