National Repository of Grey Literature 17 records found  1 - 10next  jump to record: Search took 0.00 seconds. 
Changes in rainfall-runoff regime and biogeochemistry in headwater areas
Fraindová, Kateřina ; Matoušková, Milada (advisor) ; Komínková, Dana (referee) ; Matschullat, Jörg (referee)
Headwater areas are a very important current or potential drinking water source. Their ecological value for the whole ecosystem is equally important. Headwater areas are sites with minimal anthropogenic intervention and usually the least polluted water sources. Changes in climate and rainfall-runoff (R-R) regime together with water quality in these areas affect the status and availability of water further downstream significantly. It is also one of the most sensitive areas and is an early indicator of ongoing changes. This thesis focuses on the main issues that are already ongoing and are affecting the availability of drinking water significantly. Some of these are trends in R-R regime in the context of the climate change and glacier retreat in headwater areas. As a very good example of a mid-latitude river with a complex rainfall-runoff regime, where a large impact of regional climate warming and glacier retreat are strongly manifested, The Athabasca River Basin was selected for this study. Related to this issue is the river water quality, which is influenced by changes in both temperature and R-R regime, together with the increasing occurrence of extreme hydrometeorological situations such as droughts and floods. The effects of land cover on water quality are also analysed, along with consideration of...
Development of Nutrient and Pesticide Concentrations in the Sázavka River and Their Changes in Connection with the Rainfall-runoff Regime
Pavlíková, Anna ; Havlíková, Petra (advisor) ; Matoušková, Milada (referee)
This bachelor thesis aims to study the selected parameters and nutrients of water quality in relation to the rainfall-runoff regime in the Sázavka River basin. The rainfall-runoff regime is influenced by many factors, including the climate change, which has received more and more attention in recent years. These changes may have a consequential impact on the quality of surface waters. In the first part of this paper selected parameters of water quality are presented. The aim was to try to understand their behaviour under the changing water flow dynamics. For this purpose, Czech and foreign literature was used. In this thesis there are also presented the most common statistical methods that are used in analysing geochemical parameters. The second part of this paper deals with the changes of climate- hydrological characteristics (air temperature, precipitation, snow cover and flow), the analysis of nutrients (forms of nitrogen and phosphorus) and physical parameters (water temperature and electrolytic conductivity). Lastly, metabolites of herbicides that ware above the detection limit in the watershed (acetochlor ESA, alachlor ESA, dimethachlor ESA and metolachlor ESA) were assessed. The analysis used some of the methods introduced in the research section. The regression analysis, correlation...
Changes of rainfall-runoff regime in the Stropnice river-basin
Volková, Alena ; Šobr, Miroslav (advisor) ; Janský, Bohumír (referee)
This paper deals with the rainfall-runoff regime in the Stropnice river-basin and its development. The aim of this paper is to answer the question of‚were there any changes in the runoff regime during the period 1945 - 2009, and if so, were these changes conditioned by climate or were they caused by human interventions' (e. g. river network modification, changes of the land cover, drainage systems development etc.). The single-mass and double- mass curves were used as the primary methodology. The homogeneity of the time series of mean discharge, precipitation and air temperature were statistically tested using Mann-Whitney-Pettit test and Mann-Whitney test. The Mann-Whitney-Pettit test was performed using the programme AnClim (v5.012), which is freely available online, the Mann-Whitney test was performed using SPSS 15.0. Non-parametric Mann-Kendall test was used for the trend detection, performed in MULTMK/PARTMK by C. Libiseller and A. Grimvall, also freely available online. Some changes in the runoff regime were uncovered in the early 80s', when the runoff decreased, which also happened after 1988. During these periods almost no annual flood occured. The first decrease of the runoff was caused by a drier season in the 80s'. The second decrease after 1988 was probably caused by a build-up of the...
Kinetics of selected herbicides and their biodegradation in soil and water environments
Šabršulová, Anna ; Matoušková, Milada (advisor) ; Stibal, Marek (referee)
The three most commonly used herbicides in the Czech Republic (chloracetanilides, triazines and glyphosate) are also the herbicidal compounds found in the highest concentration in surface water. After agricultural application, they interact with soil and water due to their chemical properties and environmental factors affecting them. Adsorption coefficient, solubility in water environment, precipitation and drift have high impacts on the kinetics of these herbicides and degradates emerging from them. While moving through soil, parent compounds of mentioned herbicides are actively biodegraded by microorganisms, the most effective decomposers in nature. Biodegradation in soil and water environments is accelerated or slowed by temperature, moisture, quantity of microbial communities and many other environmental factors. Even if the microbial degradation is effective in a water or soil environment, there are many other new, arising compounds whose persistence in the environment is significantly higher than that of the parent compound. Degradates can end up in surface water by run off or wash out from agricultural fields and can remain there for decades depending on their chemical properties and natural conditions. Key words: surface water, herbicides, herbicides degradation products, rainfall-runoff...
Possible assessment of runoff variability at experimental catchments in Šumava Mountains
Kalkus, Jan ; Kliment, Zdeněk (advisor) ; Královec, Václav (referee)
Main aim of the thesis is to make an outline of possible indicators of runoff variability and options how to use these indicators to compare catchments of different attributes, based on literature review. Further is mentioned general information about experimental catchments and sorts of researchers which were made there. Applicative part aims at application of selected methods for central Šumava catchment (Ptačí creek, Rokytka river) and upper reaches of Blanice river (paired catchments of Tetřívčí and Zbytinský creek). Results of this part confirm some of previous research results made in the same locations. Keywords: runoff variability, runoff regime, experimental catchment, Šumava Mountains
Rainfall-runoff regime in the headwater part of the Bystřice River basin
Šedivá, Kateřina ; Jeníček, Michal (advisor) ; Hladíková, Alice (referee)
Rainfall-runoff regime in the headwater part of the Bystřice River Abstract This bachelor thesis deals with the rainfall-runoff regime and analysis of extreme situations in the headwater part of the Bystřice River basin. At first, the area of interest is described in physical and geographical terms and the influences of individual factors on the runoff are mentioned. The text content is documented by maps. The characteristic of rainfall-runoff regime is evaluated by means of runoff variability parameters. The variability is assessed by means of collected data using charts illustrating exceedance probability of average daily discharges in years 2009 and 2010. The flow variations are evaluated on the basis of decile deviations. The distribution of monthly discharges in the Bystřice River is displayed and the monthly flow variability is described in pie graphs separately for hydrological years 2009 and 2010. The monthly balance of the runoff is also evaluated by means of statistical measures of Kr and Cv coefficients. Finally, the runoff regime evaluation is completed with exceedance probability calculation of the mean annual discharge. The assessment of selected extreme events forms an important part of the thesis. Extreme situations are compared with synoptic situations; it contributes to explain causal...
Snow regime characteristic of the Zlatý Brook in the Krušné Mountains in years 2009-2011
Hájková, Barbora ; Jeníček, Michal (advisor) ; Kučerová, Dana (referee)
This bachelor thesis is focused on the snow regime characteristic of Zlatý Brook in the Krušné Mountains. Both processes connected with snowmelt runoff and processes anticipating the runoff are described in this work. Data obtained in the catchment during the field measurements in winter periods 2008/2009, 2009/2010 and 2010/2011are described and analyzed. Measured point data are completed with information available from gauged measurements. Special attention is paid mainly to the snow depth, snow water equivalent and their spatial distribution in the catchment. Key words: snow regime, snowpack, snow water equivalent, snowmelt runoff, Zlatý brook, Krušné Mountains
Hydrological drought in headwater areas of the Ore Mountains
Vlach, Vojtěch
Changes in the hydrological cycle are one of the expected impacts of climate change. Until recently, Central European mountain ranges have not been considered to be affected by water scarcity. Nevertheless, recent years have suggested an increasing risk of drought occurrence also in these regions, which have a major impact on the water supply to rivers that drain them. The master thesis deals with the evaluation of hydrological drought in the headwater areas of three catchments in the Ore Mountains for the period from 1967 to 2018. The main aim is to compare the of hydrological drought characteristics in the catchment areas of upper Svatava River, upper Rolava River and Načetínský brook based on available hydrological and climatic data. In connection with this, the work aims to detect the long-term trends of drought occurrence in selected basins. Furthermore, the emphasis is given on the evaluation of natural conditions, especially the historical and current land cover changes in the study catchments. The results point to a significant change in the seasonality of the occurrence of hydrological drought in the second half of the studied period, when the streamflow deficits concentrate between August and October. Furthermore, increasing trends in deficit volumes were found in the catchment areas of...
Changes of geochemistry of surface water in selected catchments of the Ore Mountains
Navrátilová, Denisa ; Matoušková, Milada (advisor) ; Benešová, Libuše (referee)
This master thesis focuses on an analysis of surface water chemistry, long-term trends and the impact of drought on changes in concentrations of selected parameters in the upper Svatava, Rolava and Načetínský potok basins located in the Ore Mountains. Research on water quality in mountain spring areas is important, the consequences of various changes can be easily observed there. This work analyses the changes in surface water chemistry and discusses their possible causes, especially the impact of peat bogs and dry episodes. The parameters of water temperature, conductivity, pH, BOD5, COD, TOC, concentration of nitrate nitrogen, total phosphorus, phosphates, sodium, potassium, calcium and iron were investigated for the period 1993-2018. The available data are analysed using evaluation methods according to ČSN 75 7221 as well as box plots, Pearson correlation coefficient, PCA analysis and Mann-Kendall test. The greatest anthropogenic influence exhibited in Svatava, almost all concentrations reached their highest values there. In the Rolava and Načetínský potok basins, the influence of peatlands manifested itself by increasing the concentrations of iron, TOC and COD. The results of trends showed an increase both in pH and in surface water temperature related to an increase in air temperature, on the...
Changes of organic carbon in surface waters in headwater areas
Špringerová, Pavla ; Matoušková, Milada (advisor) ; Benešová, Libuše (referee)
Diploma thesis is focused on changes of organic carbon (OC) in surface waters in headwater areas. Thesis is in its theoretical part focused on the literature study of currently published research results of the issue. The important part is finding the possible causes of OC variability, especially landcover and soil environment. The practical part is devoted to research in experimental basins of KFGG, namely in the upper Vydra, Blanice and Rolava. The aim of this work is to clarify the relationships between organic matter concentrations and discharge rates regarding to hydrological extremes. Furthermore, the influence of river basin size and various landcover and variability of concentrations and relationship with other indicators of biogeochemism is studied. The relationship between OC and discharge rate is positive and in most river basins strong or very strong. The weakest relationship was monitored on the profiles with the highest proportion of peatlands in the river basin. In these catchments, the highest average concentrations of OC were determined in autumn, in catchments with the lower proportion of peatlands it is in summer. Analysis of rainfall-runoff events confirmed the positive relationship of OC and discharge. The lag time of the maximum OC concentration beyond the maximum discharge...

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