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Evaluating drought risk for permanent grasslands under present and future climate conditions
Trnka, Miroslav ; Schaumberger, A. ; Formayer, H. ; Eitzinger, Josef ; Hlavinka, Petr ; Semerádová, Daniela ; Dubrovský, Martin ; Možný, M. ; Thaler, S. ; Žalud, Zdeněk
Over the past years, the changing climate has affected parts of Czech Republic and Austria by drought spells of the intensity and extend that was unprecedented in previous decades. These events had a significant impact on agricultural areas, especially on the grasslands. The idea behind the GIS monitoring relies on hypothesis that the effect of weather and climate conditions on the grassland production can be estimated by models that describe certain natural processes in a simplified manner and in spatialized form.
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System for monitoring and forecast of impacts of agricultural drought
Trnka, Miroslav ; Štěpánek, Petr ; Chuchma, F. ; Možný, M. ; Bartošová, Lenka ; Hlavinka, Petr ; Balek, Jan ; Zahradníček, Pavel ; Skalák, Petr ; Farda, Aleš ; Semerádová, Daniela ; Meitner, Jan ; Bláhová, M. ; Fiala, R. ; Žalud, Zdeněk
The methodology describes how to predict soil moisture and drought intensity, and at the same time addresses reliability of the predictions and how these can be used. The ability to predict soil moisture values over a period of up to 9 days is presented through using ensemble of models for numerical weather forecasts. This method brings also new opportunities to mitigate impacts during drought events by farmers using such forecasting tools. With regard to the relatively high predictability of soil moisture and drought intensity, the methodology introduces the basic procedures and provides necessary information for the users. In this methodology, the results of 2017 drought event are presented as an example. The drought forecasting system for the Czech Republic is fully functional and is and will be available through www.intersucho.cz.
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Effect of artificially induced drought on growth and productivity of selected crops within field experiment in Bohemian-Moravian highlands
Wimmerová, Markéta ; Hlavinka, Petr ; Trnka, Miroslav ; Žalud, Zdeněk ; Pohanková, Eva
The field experiments based on manipulating the crop environment are critical for determining the crop’s response to the climatic conditions expected in the future. An experimental site in Domanínek is located by 49°31'42 N, 16°14'13 E at an altitude of 560 m (potato production area). The field experiment using rain-out shelters for soil water availability reduction was conducted in 2015/2016. The main aim of this study was to assess the impacts of different water availability (rain-out shelters vs. control) on the performance of selected field crops (spring barley, winter wheat, winter rape and silage maize). Reduction of precipitation in treatment with rain-out shelters was confirmed by measuring soil water content. The amount of precipitation during growing period was reduced by 251 mm, 277 mm, 217 mm and 240 mm for the spring barley, winter wheat, winter rape and silage maize, respectively. As a consequence, leaf area index and yields declined, however the crop responses were not consistent.
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Towards a combining of remote sensing and in situ evapotranspiration measurements
Fischer, Milan ; Jurečka, František ; Anderson, M. ; Hain, C. ; Pozníková, Gabriela ; Hlavinka, Petr ; Orság, Matěj ; Lukas, V. ; Žalud, Z. ; Trnka, Miroslav
This study provides preliminary results from combining in situ Bowen ratio energy balance (BREB) and\nevapotranspiration (ET) measurements techniques with physically based remote sensing ET estimates determined\nby the Atmosphere-Land Exchange Inverse (ALEXI) model. Evapotranspiration measurements\nand ALEXI estimates were analysed in an agricultural area close to Polkovice, Czech Republic during 2015,\nwhen a drought spell and intensive heatwaves appeared in the country. The BREB system was monitoring a\nwinter wheat (Triticum aestivum L.) field (~26 ha) while the ALEXI pixel (~5 km resolution) covered a wide\nrange of crops, including mainly winter wheat, spring barley, and winter rape. The study results showed that,\nalthough the applied methods work at different spatial scales (field vs. landscape), their combination can provide\nfurther insights into ET at both scales. For instance, such approach can be used to identify whether a specific\necosystem investigated in situ contributes to cooling or warming of the landscape.
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Application of multispectral remote sensing indices for sensing indices for estimating crop yields at field level
Jurečka, František ; Lukas, Vojtěch ; Hlavinka, Petr ; Semerádová, Daniela ; Fischer, Milan ; Žalud, Zdeněk ; Trnka, Miroslav
Remote sensing can be used for yield estimation prior to harvest and can replace or complement classical\nways of estimating crop yields. This study was undertaken in Polkovice, located in the Czech Republic’s\nHaná region. For 2015 and 2016, two data sets of satellite imagery were used: the Moderate Resolution\nImaging Spectroradiometer and the Landsat 8. Vegetation indices from satellites were compared with crop\nyields at the level of land blocks. Winter wheat and spring barley yield data, representing crops planted\nover the analysed period, were used for the comparison. The results of the index–yield comparison showed\nthat vegetation indices from remote sensing data provide reliable information for yield estimation prior to\nharvest. Indices are also able to evaluate the spatial variability of a crop within the field. The results showed\nthat remote sensing data need to have detailed spatial resolution in order to provide reasonable information\nabout yield at such a detailed level.
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Potential of flux-variance and surface renewal methods for sensible heat flux measurements at agricultural and forest surfaces
Fischer, Milan ; Katul, G. ; Pozníková, Gabriela ; Noormets, A. ; Domec, J.-C. ; Trnka, Miroslav ; King, J.
Two alternative micrometeorological methods, flux-variance (FV) and surface renewal (SR), based on\nmeasurements of high-frequency temperature fluctuation and Obukhov length stability parameter, were\ntested against eddy covariance (EC) sensible heat flux (H) measurements. The study was conducted at\nthree sites representing agricultural, forestry, and agroforestry systems. In terms of measurement setup,\nthese sites represented surface, roughness, and canopy top layer, respectively. As expected, the best match\nof all the methods was in the surface layer, whilst it was poorer in the roughness and canopy sublayers.\nSystematic deviation from EC across all three investigated surfaces was within 16% and 8% for FV and SR,\nrespectively. While FV resulted in higher correlation with EC measurements (0.93–0.98 vs. 0.89–0.97),\nSR provided less systematic biases (1.02–1.08 vs. 0.94–1.16). In general, both FV and SR provided slightly\nhigher H as compared to EC. We suggest that parallel deployment of FV and SR is useful, as both methods\nrequire the same instrumentation yet they are based on sufficiently different theories. Therefore, the agreement\nbetween FV and SR increases confidence in the results obtained and vice versa.
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Comparison of leaf area index dynamics and radiation use efficiency of C3 crops in the Czech Republic
Tripathi, Abishek ; Pohanková, Eva ; Trnka, Miroslav ; Klem, Karel
Leaf area index (LAI) and radiation use efficiency (RUE) are key parameters for plant growth and productivity.\nBecause of irregularities in weather conditions, accurate estimation of crop production requires\nunderstanding relationships between weather, LAI, RUE, and final production. It is thus important to\nstudy how the LAI dynamics, leaf area duration (LAD), and RUE are related to aboveground biomass production\nfor different crops. In our study, we compared aboveground dry mass production, LAI dynamics,\nRUE, and LAD in three C3 crops (spring barley [SB], winter wheat [WW], and oilseed rape [OSR]) in the\nCzech Republic. LAI was measured on the basis of transmitted photosynthetically active radiation, LAD\nwas calculated by counting the number of days in the growing season, RUE was measured using Beer’s\nlaw, and the aboveground dry mass was estimated at the time of harvest. Results of our study showed high\nbiomass production and RUE in SB while there was highest maximum LAI (LAImax) and LAD in OSR. We\nconcluded that LAI dynamics or LAImax do not fully reflect the crop production and that RUE may be considered\nas a better indicator for aboveground dry mass production.
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Water-use efficiency of winter wheat under heat and drought stress
Hlaváčová, Marcela ; Klem, Karel ; Novotná, Kateřina ; Rapantová, Barbora ; Urban, Otmar ; Hlavinka, Petr ; Smutná, P. ; Horáková, V. ; Škarpa, P. ; Trnka, Miroslav
Because such extreme weather events as dry spells and heat waves are expected to occur more frequently\ndue to climate change, the issue of appropriate water management for sustainable agricultural production\nis increasingly important. This study focuses on wheat, the second most widely grown cereal in the world\nand the most common cereal in European countries. The study assesses the effects of short periods (3 and\n7 days) of high temperatures (26°C as a control, 32°C, 35°C, and 38°C as daily temperature maxima from\n12:00 to 14:00) and drought stress at different developmental stages (DC 31 – beginning of stem elongation,\nDC 61 – flowering, and DC 75 – early grain filling) on water-use efficiency (WUE) in winter wheat\ncultivar Tobak. This cultivar is one of the most widespread winter wheat cultivars in Czech Republic fields.\nThe analysis of WUE showed that the cv. Tobak plants were able to withstand drought stress conditions\nthrough increased WUE. In contrast, wheat plants were stressed more markedly if exposed to higher temperatures\nand drought in combination. Generally, the wheat plants were most sensitive to drought at DC\n31.
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Comparison dietary compliance policy in DM patients in hospital and at homecare
Trnka, Michal ; Ratajová, Alena (advisor) ; Hobzová, Kateřina (referee)
Author: Trnka Michal Institution: Univerzita Karlova v Praze, 1. lékařská fakulta Title: The differences in keeping the diet principles between patients with DM in hospitals and home environments Tutor: Mgr. Alena Ratajová Number of pages: 53 Number of supplements: 2 Year: 2016 Key words: Diabetes mellitus, complications, therapy, diet, education, life quality This thesis examines the ability to keep the basic rules and diabetic diet recommendations. The goal of this work is to find out the differences in keeping the diabetic diets and possible risk of complications, especially for diabetics with DM 2T, even though the intervention of the medical staff - doctors and nurses. The thesis is divided in two parts - theoretical and research. Theoretical part describes the following terms: definition and history of diabetes, stats and prevalence of illness in CR, basic distribution and complications. Therapy - the diabetes type division in combination with patient's weight. Pharmacotherapy and physical activity as integral part of complete treatment. Following the diabetic diet for the time of treatment, where exact doses and food distribution are parts of the medical therapy, is the main part of the research. The thesis also examines the home environment, where the patient chooses groceries and defines...
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Constitutional development and the political system of Czechoslovakia after February 1948
Trnka, Michal ; Kocian, Jiří (advisor) ; Polášek, Martin (referee)
This work focuses on constitutional and political development in Czechoslovakia after the coup d'état in February 1948 that performed the Communist Party to gain absolute power. The author examines the nature of the political system immediately after the coup, and the differences between constitutional law and contemporary reality. The author assumes that some establishment not only the constitution but also other laws was just a front for illegal consolidation of a totalitarian regime. First, the work focuses to the period before February 1948, and the aspects that led to the coup, as well as the development of a new constitution, which were not completed before the coup. Second, the February events itself are analyzed with an emphasis on the extent to which took place in accordance with the constitutional order. The period after 1948, when there were illegal consolidation of power by the Communist Party, political purges and radical transformation of society, is analyzed in the following chapters. The author concludes that the future direction of Czechoslovakia was decided soon after the 1945 communist infiltration of the security forces. They also played an important role in the coup itself. While the Communist Party argued that the act of resignation of ministers and complement government was...
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