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Mathematical modelling in basin of Litavka in the framework integrated system water
Hejduk, Tomáš ; Pech, Pavel (advisor) ; Máca, Petr (referee)
These thesis brings new findings in flood issues, which importance has been sharply increasing in the light of last years experience. Hypotheses about the usefulness of hydrological measurements in the creation of computational geometry watercourses, as well as using the data from aerial laser scanning in the preparation of computer tracks water flows have been confirmed. Presented papers introduce the use of new technologies, knowledge and other results of applied research in the field of preparation of input data for hydrodynamic models, geographic information systems, personal identification and early warning and information sharing to support the elimination of consequences of natural disasters or traffic accidents. The above presented findings about the use of airborne laser scanning data and synthesis these data with hydrological measurements are of great importance for the improvement of flood prevention. Another practical use of these findings lies in urbanism planning and flood forecasts. The effort is to increase the security of citizens in the case of threats to their security through early warning - ie. Preventative protection by results of conducted research in the field of mathematical modelling rainfall-runoff and passage of flood flows in the river system providing new knowledge for the identification and registration of persons. During the research conducted, the attention was paid to define tools supporting integrated activities of the state security and rescue forces, including increased education and communication between state administration, local governments and the public. However the main goal of this work is to prevent the effects of natural and anthropogenic risks to human health and property of citizens. The attention is paid especially on the most common natural hazard represented by the floods.
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Using artifical neural network for ice phenomena prediction on the lower Berounka
Šebestová, Lucie ; Máca, Petr (advisor) ; Havlíček, Vojtěch (referee)
Ice phenomena on watercourses are commonly occurring effect in winter period. In most places do not cause any complication, but in certain places their occurrence is more frequent and in conjunction with forming ice phenomena into dangerous, as a break-up ice jam or a freeze-up ice jam, can lead to the formation of ice flood. Such places is affected lower Berounka watercourse in section Křivoklát - Vltava confluence. Occurrence and formation of ice phenomena depends on ice regime, which lower Berounka causing frequent problems. Ice regime is the interplay of many factors and ice phenomena are thus generally very difficult to predict because of strongly nonlinear relationships. Artificial neural networks excel in ability to learn on examples, in this case historical data, and ability to apply the knowledge gained on the data present and the future. This work uses multilayer perceptron neural network to realization of ice phenomena prediction based on historical flow and temperature data from the years 1887 - 1940 from the measuring station Křivoklát, which is a place of frequent occurrence of dangerous ice phenomena. The results provided by the learned neural network are comparable to the standard model used in modeling of ice phenomena. Obtained outputs confirmed the possibility of the successful application of neural networks in this area. Their use is possible as e.g. a part of information (warning) system or a system for predicting the occurrence of ice phenomena during winter season, which may lead to the alleviation of their impact on watercourse, surrounding area and residents.
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Drought Indices in Panama Canal
Gutiérrez Hernández, Julián Eli ; Máca, Petr (advisor)
Panama has a warm, wet, tropical climate. Unlike countries that are farther from the equator, Panama does not experience seasons marked by changes in temperature. Instead, Panama's seasons are divided into Wet and Dry. The Dry Season generally begins around mid-December, but this may vary by as much 3 to 4 weeks. Around this time, strong northeasterly winds known as "trade winds" begin to blow and little or no rain may fall for many weeks in a row. Daytime air temperatures increase slightly to around 30-31 Celsius (86-88 Fahrenheit), but nighttime temperatures remain around 22-23 Celsius (72-73 Fahrenheit). Relative humidity drops throughout the season, reaching average values as low as 70 percent. The Wet Season usually begins around May 1, but again this may vary by 1 or 2 weeks. May is often one of the wettest months, especially in the Panama Canal area, so the transition from the very dry conditions at the end of the Dry Season to the beginning of Wet Season can be very dramatic. With the arrival of the rain, temperatures cool down a little during the day and the trade winds disappear. Relative humidity rises quickly and may hover around 90 to 100% throughout the Wet Season. Drought forecasts can be an effective tool for mitigating some of the more adverse consequences of drought. The presented thesis compares forecast of drought indices based on seven different models of artificial neural networks model. The analyzed drought indices are SPI and SPEI-ANN Drought forecast, and was derived for the period of 1985-2014 on Panama Canal basin; I've selected seven of sixty-one Hydro-meteorological networks, existing in the Panama Canal basin. The rainfall is 1784 mm per year. The meteorological data were obtained from the PANAMA CANAL AUTHORITY, Section of Water Resources, and Panama Canal Authority, Panama. The performance of all the models was compared using ME, MAE, RMSE, NS, and PI. The results of drought indices forecast, explained by the values of seven model performance indices, show, that in Panama Canal has problem with the drought. Even though The Panama is generally seen as a wet country, droughts can cause severe problems. Significant drought conditions are observed in the index based on precipitation and potential evaporation found in this thesis; The Standardized Precipitation Index (SPI), the Standardized Precipitation Evapotranspiration Index (SPEI), were used to quantify drought in the Panama Canal basin, Panama Canal, at multiple time scales within the period 1985-2014. The results indicate that drought indices based on different variables show the same major drought events. Drought indices based on precipitation and potential evaporation are more variable in time while drought indices based on discharge. Spatial distribution of meteorological drought is uniform over Panama Canal.
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The Bathymetry of Němčice reservoir
Prchal, Jan ; Máca, Petr (advisor) ; Bašta, Petr (referee)
Bathymetric measurements are important for mapping relief of current reservoirs and streams. Due to the lack of similar measurements in the Czech Republic is presented diploma thesis focused on the implementation of the first bathymetric survey on the water reservoir located on the basin Němčice - Sedlický stream. As a part of the work was done bathymetric data collection device River Surveyor M9 data processing interpolation procedures and evaluate the mutual comparison of estimation results. It was also evaluated the effect of the resolution to the retention volume of the tank and its sedimentations regime. Based on the evaluation of the measurement is based on a minimum average error method Universal Kriging. Processed data were measured during the year 2015. The result of the work can serve as a guide for subsequent measurements and estimates bathymetric data on a similar small reservoirs in the catchment areas of the Czech Republic.
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Short duration precipitation extremes in the Czech Republic
Roub, Tomáš ; Hanel, Martin (advisor) ; Máca, Petr (referee)
The aim of this paper is to assess precipitation records from 182 monitoring stations. For every station intensities of short duration rain events are evaluated and compare with intensities presented in the work of Josef Trupl Intensity krátkodobých dešťů v povodích Labe, Odry a Moravy. For comparison always nearest monitoring station with an appropriate altitude was selected. The comparison is done for 3 data groups based on quality code of the records. Furthermore, stations with overlapping records are compared.
The review part deals with rainfall and the methods of assessment of short duration rainfall intensities. The following part describes the selected historical rainfall series, which serve as a basis for estimation of design rainfall.
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Disaggregation of rainfall data
Němeček, Václav ; Máca, Petr (advisor) ; Heřmanovský, Martin (referee)
The bachelor thesis studies selected disaggregation methods, which are used for the description of hydrological time series. The literature search provides the survey of important disaggregation methods. The special attention is put on disaggregation method using the Wavelet coefficients. The methods of moment were applied on estimation of parameters for disaggregation model. Variance reduction function were estimated for selected precipitation time series obtained from the MOPEX database.
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Using of GIS in hydrology
Svačinová, Michaela ; Bašta, Petr (advisor) ; Máca, Petr (referee)
This bachelors thesi deals with usage of geographic information systems (GIS) in hydrology. In this work are described specific hydrologic analyses, which are based on the digital terrain model (DTM). Work introduced individual flow direction algorithms, its usage is necessary part of every GIS software including hydrological tools. There are described individual commercial and non-commercial GIS softwares used in hydrological. In practical part Arc Hydro (ArcGIS extensit) and SAGA GIS software are used for creating hydrological analyses in Jedlová broog watershed (Liberec region) with usage of DTM of fifth generation and terrain topology. Arc Hydro and SAGA GIS softwares are compared on base of their graphical user interface (GUI) and generated results.
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