National Repository of Grey Literature 7 records found  Search took 0.01 seconds. 
Using program Rosetta to estimate of soil moisture retention curves from experimental size Bohaté Málkovice
Čermák, Petr ; Doležal, Petr (referee) ; Kameníčková, Ivana (advisor)
Hydraulic characteristics are the most important properties of soil, i.e. retention curve of soil moisture and hydraulic conductivity. Hydraulic conductivity of soil characterizes the ability of the soil to conduct water. Retention curve expresses the relationship between moisture and moisture potential of soil. The running of retention curve is influenced by many factors, eg. grain size and mineralogical composition, content of humus, reduce bulk density and structure of soil. Measurement of retention curves takes a lot of time and money in laboratory conditions therefore pedotransfer functions seem to be an alternative solution. The thesis aims to estimate moisture retention curves of soil in a selected area of interest in South Moravia using program Rosetta (Schaap, 2003). Data of granularity (% content of clay, sand and dust), bulk density of soil and hydrolimits field water capacity and wilting point were used as predictors in individual models of program Rosetta. Data of grain were matched by FAO / USDA system. Retention curves of soil moisture were measured on a sand tank and overpressure devices. The measured retention curves were parameterized by RETC program. Estimated retention curves were graphically compared with measured to determine the quality of the estimate. The accuracy of the estimate was assessed by correlation coefficient R of determination coefficient R2 and standard error SMRE. Usability own derivatives pedotransfer functions is hard to say due to the size of the input data file. I would recommend further verification of data at the other localities in south Moravia.
Determination of hydraulic characteristics of soil in a selected area
Salač, Jan ; Doležal, Petr (referee) ; Kameníčková, Ivana (advisor)
The diploma thesis is focused on issues of measurement and evaluation of hydraulic characteristics of soil. In the literary research, the definitions of hydraulic conductivity and retention curve of soil moisture, their measurements in laboratory and field conditions and the prediction of these characteristics by using of pedotransfer functions. In the practical part of the diploma thesis, an evaluation of the hydraulic conductivity of soil from the experimental areas near the village Bohaté Málkovice. Two-cylindrical and mini-disc infiltration meters were used for field measurements, and a constant-gradient permeameter was used in the laboratory. Physical and empirical equations were used to evaluate the hydraulic conductivity. The results were processed numerically, tabulated and then compared.
Pedotransfer functions for estimation of moisture retention curves of medium-heavy soils of South Moravia
Gavlasová, Iva ; Doležal, Petr (referee) ; Kameníčková, Ivana (advisor)
The most important characteristics of each soil is its hydro-physical properties, which include retention curve. Retention curve expresses the relationship between humidity and pressure head. It is course affected by many factors such as grain size and mineralogical composition, humus content, structure and bulk density of dry soil. This thesis deals with direct and indirect determination of one of the basic hydraulic characteristics of the soil, soil moisture retention curve. For laboratory determination of moisture retention curves were used for sand tank and pressure instruments. Measured body retention curves were optimized RETC program.For indirect determination of retention curves were used Pedotransfer function by Wösten et . al .(1998 ) , derived from the European soils and under HYPRES Šútora and Štekauerová (2000). As in the project Wösten et al . (1998), PTF were processed for arable land in the area. The accuracy of both models PTF was assessed by the correlation coefficient R and standard error RMSE. Simple models PTF provide estimates of retention curves with sufficient accuracy for practical use in the locality.
Determination of hydraulic characteristics of soil in a selected area
Salač, Jan ; Doležal, Petr (referee) ; Kameníčková, Ivana (advisor)
The diploma thesis is focused on issues of measurement and evaluation of hydraulic characteristics of soil. In the literary research, the definitions of hydraulic conductivity and retention curve of soil moisture, their measurements in laboratory and field conditions and the prediction of these characteristics by using of pedotransfer functions. In the practical part of the diploma thesis, an evaluation of the hydraulic conductivity of soil from the experimental areas near the village Bohaté Málkovice. Two-cylindrical and mini-disc infiltration meters were used for field measurements, and a constant-gradient permeameter was used in the laboratory. Physical and empirical equations were used to evaluate the hydraulic conductivity. The results were processed numerically, tabulated and then compared.
Soil carbon sequestration in northern part of Czech karst
Polická, Petra ; Šefrna, Luděk (advisor) ; Janderková, Jana (referee)
Due to climate change there is a growing concern for soil organic carbon reservoires. The soil is the largest terrestrial pool of organic carbon and its balance is being increasingly disturbed by conversion of natural to managed ecosystem (for agriculture, forestry and urbanization). There are still large uncertainities with estimating real amount of organic carbon sequestrated in soils. Therefore a number of regional and national soil inventories and monitoring networks are currently established or tested to verify soil carbon changes. Thesis is focused on estimation of soil organic carbon pools in the area of Czech basic map Beroun 12-41-08. It evaluates available soil data and restrictions of their use. Especially is focused on comprehensive soil survey undertaken between 1961 and 1970, on soil properties change in time and how to get missing bulk densities of the soil, particularly through pedotransfer functions. Powered by TCPDF (www.tcpdf.org)
Using program Rosetta to estimate of soil moisture retention curves from experimental size Bohaté Málkovice
Čermák, Petr ; Doležal, Petr (referee) ; Kameníčková, Ivana (advisor)
Hydraulic characteristics are the most important properties of soil, i.e. retention curve of soil moisture and hydraulic conductivity. Hydraulic conductivity of soil characterizes the ability of the soil to conduct water. Retention curve expresses the relationship between moisture and moisture potential of soil. The running of retention curve is influenced by many factors, eg. grain size and mineralogical composition, content of humus, reduce bulk density and structure of soil. Measurement of retention curves takes a lot of time and money in laboratory conditions therefore pedotransfer functions seem to be an alternative solution. The thesis aims to estimate moisture retention curves of soil in a selected area of interest in South Moravia using program Rosetta (Schaap, 2003). Data of granularity (% content of clay, sand and dust), bulk density of soil and hydrolimits field water capacity and wilting point were used as predictors in individual models of program Rosetta. Data of grain were matched by FAO / USDA system. Retention curves of soil moisture were measured on a sand tank and overpressure devices. The measured retention curves were parameterized by RETC program. Estimated retention curves were graphically compared with measured to determine the quality of the estimate. The accuracy of the estimate was assessed by correlation coefficient R of determination coefficient R2 and standard error SMRE. Usability own derivatives pedotransfer functions is hard to say due to the size of the input data file. I would recommend further verification of data at the other localities in south Moravia.
Pedotransfer functions for estimation of moisture retention curves of medium-heavy soils of South Moravia
Gavlasová, Iva ; Doležal, Petr (referee) ; Kameníčková, Ivana (advisor)
The most important characteristics of each soil is its hydro-physical properties, which include retention curve. Retention curve expresses the relationship between humidity and pressure head. It is course affected by many factors such as grain size and mineralogical composition, humus content, structure and bulk density of dry soil. This thesis deals with direct and indirect determination of one of the basic hydraulic characteristics of the soil, soil moisture retention curve. For laboratory determination of moisture retention curves were used for sand tank and pressure instruments. Measured body retention curves were optimized RETC program.For indirect determination of retention curves were used Pedotransfer function by Wösten et . al .(1998 ) , derived from the European soils and under HYPRES Šútora and Štekauerová (2000). As in the project Wösten et al . (1998), PTF were processed for arable land in the area. The accuracy of both models PTF was assessed by the correlation coefficient R and standard error RMSE. Simple models PTF provide estimates of retention curves with sufficient accuracy for practical use in the locality.

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