The main task of this diploma thesis is to evaluate function of system of open drainage channels and its impact on runoff from Tetřívčí brook forest catchment in Šumava mountains region, upper basin of the Blanice River. Catchment area is only 1,62 km2 and total length of all channels is over 12 km, so it's very important feature of this catchment. The first task was to explore to explore all the channels and set them to the map. Most of used data were measured manually, only precipitation and water level in main stream were measured by automatic gauges. It's not possible to compare results with state without channels, what is the main obstacle for data analysis. Measured channels normally contribute to total catchment runoff by 6 % to 39 %. About 20 % of channel length participate in runoff process in dry periods, in wet periods it can be even 90 % of channel length, what indicates functionality of drainage system. Actual soil saturation in the catchment is very important factor, it's expressed either by index API 5 (based on precipitation) or by groundwater level in 5 measured in separate drills. It's proved by channels responses in well-saturated periods. Runoff in measured channels raises up significantly after even very small precipitations of 1,7 mm. All results are suggesting, that total...

Daugiau, kaip 80 % hidrografinio tinklo Lietuvoje sudaro melioracijos kanalai. Daugiau kaip 30 % bebrų populiacijos gyvena šiuose kanaluose. Bebrų veikla neretai trikdo normalų melioracijos sistemų funkcionavimą. Tyrimui pasirinktos dviejuose skirtinguose kraštovaizdžiuose esančios bebravietės (Molėtų bei Panevėžio rajonuose). Šiame darbe buvo tiriama bebraviečių tankumas, pasiskirstymas, erdvinės charakteristikos bei statybinės veiklos intensyvumas melioracijos kanaluose. Nustatytas bebrų poveikio mastas bei šio masto pokyčiai. Ištirtose teritorijose bebrų veikiama pusė melioracijos kanalų linijinio ilgio. Per 10 metų (1995-2005) bebraviečių skaičius melioracijos kanaluose praktiškai nepakito, taigi nekito ir melioracijos sistemoms daromas poveikis. / More than 80 % of hydro-graphical network in Lithuania is composed of drainage channels. More than 30 % of beaver populations in Lithuania live in drainage channels. Beaver activity often dislocates irrigations systems. This research was taken in two different landscapes. Beaver sites were visited in Moletai and Panevezys districts. Density, spread, dimensions and constructional activity were recorded in drainage channels. Also this study shows influence over the environment of changing number in beaver populations. Half of linear lengths of irrigation systems are influenced by beaver activity. The number of beaver sites did not change in a ten year period (1995-2005) as well as did not change the damage caused by beaver activity.

Thesis (Ph. D.)--Ohio State University, 2006. / Title from first page of PDF file. Includes bibliographical references (p. 139-141).