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This diploma thesis deals with clarification of an influence of rain discharge events on nutrients loss from drainage area and which rain discharge events are the main cause of the loss. Within the scope of this the influence of these episodes on drainage area of the Jenínský brook will be quantified, more specifically sub-drainage area J2. The thesis describes not only the circle of water in the nature, specification of rain drainage events origin, but also the very factors which influence the water drainage and the loss of nutrients caused by the drainage. Furthermore, the basic nutrients which appear the most often and in the biggest quantities in our waters are described, these being nitrogen and phosphor and last but not least what is described here is the total loss of nutrients in water during rain drainage events. The description of a drainage area itself and a water intake profile J2 follows. The water intake profile J2 was the source for processing the results. The results were processed by several computational methods, which were compared to each other in the end. The loss during 5 extreme rain events was calculated and so was their percentage representation in the total annual losses and the consecutive evaluation of the results.

This work aimed to evaluate long-term changes of selected chemical and physical parameters of rainwater from their own rain gauge stations Stropnicko. Chemical and physical parameters influence the rate of loss of substance in the landscape through the soil environment. In particular, the amount and concentration of dissolved sulphates and nitrates, affecting the value of the current pH. Samples were taken from their own rain gauge stations Stropnicko. Names of stations from which samples were taken are Horní Stropnice, Nakolice, Paseky and Nové Hrady. Rainfall were measured between the years 2005-2011 and were subjected to chemical analysis.

The influence of precipitation on runoff characteristics of tile drainage systems and nitrate concentrations in drainage water were evaluated in this thesis. The Jeninsky stream catchment is located at the foothill of Sumava Mountains near the border checkpoint Dolni Dvoriste. Extensive agriculture (pasture) is practised in the catchment as well as surrounding areas. Above mentioned evaluated characteristics were measured on two closure profiles of tile drained subcatchments. Discharges were measured continously, water quality was sampled forthnigtly. Evaluated hydrologic year 2007 was rich in rainfall {--} the precipitation amounted to 892 mm, which is classified as a wet year, despite of 41 days long dry period. Runoff characteristics don{\crq}t vary much in both subcatchments, due to similar area and land use on researched catchments. Long dry period did not cause zero discharges. The progress of nitrate concentrations in subcatchments is characterized by low variations in values. Relatively low values (90-percentil of nitrate concentrations in individual catchments belong to II. and III. class of water quality limits set by Czech legislative) occured in the catchment. These values correspond or slightly exceed values monitored on surrounding simirarly used areas, but are significantly lower than values monitored in areas, where intensive agriculture is practised. This confirms positive influence of grassing on nitrate pollution of drainage and surface water.

This work deals with comparison of precipitation and discharges in relation to nitrate concentrations in the Jenínský stream. The locality is situated on the east of town Vyšší Brod in the southern part of Bohemia. Since the 80`s this small catchment is research area and in the year 2004 The Faculty of Agriculture has continued in this research in Jenínský stream catchment. The backgrounds for this work are data of hydrological year 2006 which are gained from continuous measuring and scanning in small catchment Jenín. There is a recurrency to generalize the precipitation impact which induce changes of discharges on the closing device in small catchment.

Diploma work deals with evaluation of nitrate concentration on trial on rainfall and runoff on partial profiles of Kopaninsky stream. From chemical point of view nitrates are nitric acid salts (e.g. potassium or soda salts) and forms natural part of vegetable and animal masses (metabolism product). At common concentration is not harmful. Nitrates in bodies they can chemical change on nitrite and then further on nitrosamines (organic matters containing nitrogen in its molecule) with carcinogenic effects. Measuring on monitoring profiles past over fortnightly. Strong seasonal progress of nitrate concentrations is perceptible. Highest nitrate concentrations were measured mostly in spring and lowest concentrations in autumn. Maximum nitrate concentration on whole catchment achieves the value 181 mg.l-1 and minimum nitrate concentration achieves the value 0.5mg.l-1. There is nearly no influence on nitrate concentrations by a rainfall. Mostly nitrate concentrations in this catchment gently heighten or stay the same after rainfall, which witness about the fact, that pollution has areal character. As is the influence of land use on runoff in literature described, wasn't this influence in observed micro catchments proved.