Josef Krasa

Josef Krasa
Czech Technical University in Prague | ČVUT · Department of Landscape Water Conservation

Assoc. Prof.

About

77
Publications
10,043
Reads
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696
Citations
Citations since 2017
32 Research Items
413 Citations
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2017201820192020202120222023020406080100
2017201820192020202120222023020406080100
2017201820192020202120222023020406080100
Introduction
Josef Krasa currently works at the Department of Landscape Water Conservation, Czech Technical University in Prague. Josef does research in Soil Science, Water Science and Irrigation and Water Management. Current projects are focused on UAV based monitoring of soil erosion, sediment transport analyses in large scales, phosphorus transports, eutrophication studies.
Additional affiliations
March 2011 - October 2015
Czech Technical University in Prague
Position
  • Professor (Associate)
January 2009 - December 2010
Czech Technical University in Prague
January 2004 - February 2019
Czech Technical University in Prague
Position
  • Professor (Associate)

Publications

Publications (77)
Preprint
Full-text available
In the Czech Republic, the Universal Soil Loss Equation provides the basis for defining the soil protection strategy. Field rainfall simulators were used to define the actual cover-management factor values of the most extensively seeded crops in the Czech Republic. More than 380 simulations between 2016 and 2021 provided data. The methodology focus...
Preprint
Every application of soil erosion models brings the need of proper parametrization, i.e., finding physically or conceptually plausible parameter values that allow a model to reproduce measured values. No universal approach for model parametrization, calibration and validation exists, as it depends on the model, spatial and temporal resolution and t...
Article
Although wheel tracks cover only a small portion of the surface of agricultural fields, their effect on surface runoff and sediment transport is substantial. Wheel tracks change the microrelief of the soil surface, and influence how the surface is further altered by rainfall and runoff. This study presents a plot-scale microrelief analysis of a til...
Article
Full-text available
The Czech landscape has undergone various changes over the last 100 years and has been mainly adapted agriculturally for economic purposes. This has resulted, among other things, in reservoirs being clogged with sediment. The Vrchlice Reservoir was built in 1970 to supply drinking water for around 50,000 inhabitants, and increased sedimentation has...
Article
Full-text available
Reinforcing the small water cycle is considered to be a holistic approach to both water resource and landscape management. In an agricultural landscape, this can be accomplished by incorporating agricultural conservation practices; their incorporation can reduce surface runoff, increase infiltration, and increase the water holding capacity of a soi...
Article
Full-text available
Accelerated soil erosion is a major threat to soil, and there are great variations in the rate of soil erosion over time due to natural and human-induced factors. The temperate forest zone of Russia is characterized by complex stages of land-use history (i.e. active urbanization, agricultural development, land abandonment, etc.). We have for the fi...
Article
Full-text available
Článek popisuje metodu stanovení erodovatelnosti nesoudržných zemědělských půd pomocí měření kritického tečného napětí. Pro určení kritického tečného napětí byl použit tzv. „Jet Erosion Test“ (JET). Měření bylo provedeno pomocí modifikované zmenšené verze zařízení Mini-JET. Zařízení je velmi vhodné pro terénní měření, neboť je malé, lehké, spotřebu...
Article
An understanding of splash erosion is the basis to describe the impact of rain characteristics on soil disturbance. In typical splash cup experiments, splashed soil is collected, filtered and weighed. As a way to collect additional data, our experiments have been supplemented by a photogrammetric approach. A total of three soils were tested across...
Article
Full-text available
In the face of future climate change, Europe has encouraged the adoption of biofuel crops by its farmers. Such land-use changes can have significant impacts on the water balance and hydrological behavior of a system. While the heavy pesticide use associated with biofuel crops has been extensively studied, the water balance impacts of these crops ha...
Article
Full-text available
Accelerated soil erosion by water has many offsite impacts on the municipal infrastructure. This paper discusses how to easily detect potential risk points around municipalities by simple spatial analysis using GIS. In the Czech Republic, the WaTEM/SEDEM model is verified and used in large scale studies to assess sediment transports. Instead of com...
Article
Full-text available
Small earthen dams usually lack a detailed monitoring system that would provide high-resolution data concerning changes in seepage flow. Geophysical methods and remote sensing are useful techniques for non-destructive and non-invasive investigation of subsurface processes. We have utilized a combination of electrical resistivity tomography (ERT), c...
Article
Full-text available
In the European Union, soil erosion is identified as one of the main environmental threats, addressed with a variety of rules and regulations for soil and water conservation. The by far most often officially used tool to determine soil erosion is the Universal Soil Loss Equation (USLE) and its regional adaptions. The aim of this study is to use thr...
Article
Full-text available
This article outlines the major scientific objectives of the SHui project that seeks to optimize soil and water use in agricultural systems in the EU and China, by considering major current scientific challenges in this area. SHui (for Soil Hydrology research platform underpinning innovation to manage water scarcity in European and Chinese cropping...
Article
Full-text available
The article describes the method, the source data, and the results of analyses of bare soil by remote sensing and its relation to soil erosion risk. The method was tested on the parcels of AGRA Řisuty, s. r. o. Data from the satellites Landsat 8 and Sentinel 2 were used for detecting the presence of vegetation cover on each parcel. Furthermore, exi...
Article
Full-text available
This paper addresses changes in land use and in the spatial distribution of land units and their influence on the soil erosion risk in two areas with a different geomorphology and a different historical and political development: an intensively-used lowland agricultural watershed in central Bohemia, Czech Republic, and a partially hilly agricultura...
Article
Full-text available
Intense rainfall-runoff events and subsequent soil erosion can cause serious damage to the infrastructure in residential areas in Europe countries and all over the world. In the Czech Republic, the Ministry of the Interior has supported an analysis dealing with the risks to residents, infrastructure, and water bodies from flash floods and sediment...
Article
Full-text available
Modern non-contact methods for data acquisition are becoming widely used for monitoring soil erosion and for assessing soil degradation after rainfall events. Photogrammetric methods are especially favored to obtain a detailed and precise digital surface model (DSM) of the surveyed area. This paper introduces the algorithm and its Python implementa...
Poster
Full-text available
The aim of this contribution is to assess effect of seedbed cultivation and wheel-track compaction on runoff dynamics with a special regard on shallow subsurface processes which haven’t been often taken into the account. Two artificial rainfall experiments on two plots with and without wheel-track were undertaken during the measuring campaign. Surf...
Conference Paper
Research of water regime on cultivated soils is important for planning of landscape protection measures which help to preserve the water in the landscape. The aim of this contribution is to assess effect of seedbed cultivation and wheel-track compaction on runoff dynamics with a special regard on shallow subsurface processes which haven’t been ofte...
Article
Full-text available
Degradation of reservoir dams can lead to water percolation through dam structure. Here, close-range photogrammetry and UAV (Unmanned Aerial Vehicle) thermal imagery can be used to monitor differences in dam moisture. The article presents a study of the dam of Podvinak Fishpond (Czech Republic). The TDR (Time Domain Reflectometry) data (soil moistu...
Article
Full-text available
Small earth dams usually lack the detailed seepage monitoring system that would provide high resolution data on changes in seepage flow. Alternative solution is monitoring of the temperature and electrical resistivity in the body of the dams. Geophysical methods are useful techniques for a non-destructive exploration of the subsurface. We have util...
Article
Full-text available
Field observations and consecutive modelling of soil erosion events proved to be essential for understanding and predicting erosion and sediment transport. An experimental approach often utilizes a large variety of rainfall simulators. In this technical note a complex methodology is introduced, using a mobile rainfall simulator developed at the Cze...
Research
Full-text available
The objective of the Methodology for assessment of pollution sources influence on water reservoirs eutrophication is to provide a universal guide to identify all significant anthropogenic sources of phosphorus in the basin of any water reservoir and determine their potential for eutrophication. Eutrophication potential in this methodology is define...
Article
Full-text available
This paper presents a newly-derived method for directly determining the amount of transported dissolved phosphorus by water erosion. The results of the method are compared to prediction based on enrichment ratio (as proposed by Sharpley) and average share of dissolved phosphorus (DP) in total transported phosphorus (5%) that is widely used in the C...
Article
Full-text available
This study is focused on the historical evolution of a heavily eroded field with discontinuous grass cover on a major thalweg (ephemeral gully). Tens of parcels originally formed a protective pattern in the study area, and the thalweg was permanently covered with grass. During the period of collectivization, the field structure had been unified int...
Conference Paper
Full-text available
Many sources of pollution in the reservoirs and lakes watershed may contribute to the eutrophication of water in varying degrees. About significance of phosphorus sources decides emitted forms of phosphorus mainly, but it also affects localization of sources in the watershed, seasonal intake, amount of retention elements between source and the rese...
Article
Full-text available
Number of erosive rains, kinetic energy of erosive rains and factor of erosive efficiency of rains according to the USLE methodology were assessed by two methods of erosive rains determination. The first method (VAR1) defined erosive rains by intensity ≥ 0.4 mm· min−1; total ≥ 12.5 mm and the second method (VAR2) by intensity ≥ 6 mm· 15 min−1; tota...
Book
Full-text available
Jakub Jankovec Výzkumný ústav rostlinné výroby, v.v.i. • Vilém Pavlů • Jan Gaisler • Lenka Pavlů • František Paška Doba projektu: od září 2012 do září 2014 Číslo projektu: 100114993 Projekt byl financován z prostředků EU a ze státního rozpočtu České republiky. http://aquanisa.ihi-zittau.de ISBN 978-3-86780-404-2
Conference Paper
Full-text available
Soil erosion by water is one of the main degradation processes on agricultural lands in the Czech Republic. The team on Department of Irrigation, Drainage and Landscape Engineering at the Czech Technical University in Prague have been involved in experimental measuring of surface runoff, soil erosion and soil transport processes for several decades...
Article
Full-text available
Eroze patří mezi významný zdroj znečištění našich vod. Plány povodí pak vpřípadech, kdy vodní útvar nedosáhne dobrého stavu ve smyslu požadavků Rámcové směrnice vodní politiky, musí obsahovat nápravná opatření nezbytná kdosažení dobrého stavu vod. Vuplynulých čtyřech letech probíhal projekt, jehož účelem bylo připravit postupy apodklady pro usnadně...
Article
Full-text available
Soil erosion by water is one of the main degradation processes on agricultural lands in the Czech Republic. The team on Department of Irrigation, Drainage and Landscape Engineering at the Czech Technical University in Prague have been involved in experimental measuring of surface runoff, soil erosion and soil transport processes for several decades...
Article
Full-text available
This article presents the comparison between the indirect determination of the transported dissolved phosphorus (using the equation of Sharpley, 1995), based on usually used enrichment ratio and assumed share of the dissolved phosphorus in the total transported phosphorus during the erosion event, and the direct determination of the transported dis...
Article
Full-text available
The importance of soil loss by water erosion becomes more eminent with the ongoing climate change, where more extreme precipitations in middle Europe are anticipated. The amount of soil transported from the field plot can substantially differ according to the intensity of rill erosion. The capability of mathematical models to predict appearance of...
Conference Paper
Full-text available
V příspěvku je představen metodický koncept hodnocení eutrofizačního potenciálu zdrojů fosforu v povodí libovolné vodní nádrže. Eutrofizační potenciál je zde chápán jako mnohorozměrná funkce velikosti produkce fosforu, podílu emitovaných forem fosforu, vzdálenosti od nádrže, sezónnosti emisí a množství retenčních prvků mezi zdrojem a nádrží. Umožňu...
Conference Paper
Full-text available
To help the implementation of Water Framework Directive in the Czech Republic the four-year project was set-up to assess eutrophication factors in endangered catchments. The assessed area covers approximately 40% of the area of the Czech Republic (almost 31 500 km2). The erosion phosphorus loads are modeled by WATEM/SEDEM model adapted for the purp...
Article
The article shows results of topographic factor (the LS factor in USLE) derivation enhancement focused on detailed Airborne Laser Scanning (ALS) based DEMs. It describes a flow paths generation technique using triangulated irregular network (TIN) for terrain morphology description, which is not yet established in soil loss computations. This techni...
Conference Paper
V př'ispvevku je představen metodický koncept hodnocen'i eutrofizavcn'iho potenciálu zdrojů fosforu v povod'i libovolné vodn'i nádrvze. Eutrofizavcn'i potenciál je zde chápán jako mnohorozmverná funkce velikosti produkce fosforu, pod'ilu emitovaných forem fosforu, vzdálenosti od nádrvze, sezónnosti emis'i a mnovzstv'i retenvcn'ich prvků mezi zdroje...
Book
Full-text available
Hodnocení ohroženosti vodních nádrží sedimentem a eutrofizací podmíněnou erozí zemědělské půdy certifikovaná metodika pro praxi Metodika je připravena ve spolupráci institucí v rámci projektu QI102A265. Vydalo ČVUT v Praze, Fakulta stavební, 2013
Article
Universal Soil Loss Equation (USLE) is a widely used tool for the assessment of soil erosion in the Czech Republic as well as in many other countries. C factor is one of the six factors composing USLE. This factor represents vegetation cover and management on agricultural land. Its values were derived based on a comparison of the soil loss from a p...
Article
Full-text available
Sediment transport and water quality in Máchovo Lake (Czech Republic) Máchovo Lake is a historical reservoir founded by Czech King Charles IV. in 14th century. Located in northern part of central Bohemia it has been widely used for recreation purposes for many decades (or even centuries). Its catchments (ca 100 sq km) consist of intensively used ag...
Article
For the Czech Republic one of the most dangerous effects of soil erosion and sediment transport processes is water quality degradation, due to secondary pollutants. The WaTEM/SEDEM model, developed at Katholic University (KU) Leuven in Belgium, was tested as a prediction tool within several different Czech catchments. WaTEM/SEDEM is a spatially dis...
Article
At the Department of Drainage, Irrigation and Landscape Engineering (CTU Prague) we use several mathematical models for soil erosion, sediment transport and surface runoff assessment. Here we continuously struggle for successful models parameterizations. One of the typical coefficients usually taken from literature instead of measurements is surfac...
Article
Full-text available
The EU Water Framework Directive (WFD) brings relatively strict demands concerning surface waters protection, soil protection and watershed management. Water quality and soil conservation are among the priorities of European environmental policy. The aims and corresponding limits are clearly and strictly formulated but the ways how to fulfill the t...
Article
Full-text available
Katedra hydromeliorací a krajinného inženýrství, Fakulta stavební, ČVUT v Praze, Thákurova 7, 166 29, Praha 6, Česká republika josef.krasa@fsv.cvut.cz Abstrakt. V roce 2001 byla na pracovišti Katedry hydromeliorací a krajinného inženýrství Fakulty stavební ČVUT v Praze vytvořena pomocí prostředků GIS mapa ztráty půdy a transportu sedimentu pro celo...
Article
Full-text available
At present large collective fields in the Czech Republic are being split up into smaller spatial units. Moreover, a large number of former state farms are abandoned, resulting in an increase of the area of set-aside land. Between 1990 and 2000 the area of pasture land in the Czech Republic increased 150%. The ongoing landscape dynamics has a signif...
Chapter
Provides a unique and comprehensive assessment of soil erosion throughout Europe, an important aspect to control and manage if landscapes are to be sustained for the future.Written in two parts, Soil Erosion in Europe primarily focuses on current issues, area specific soil erosion rates, on and off-site impacts, government responses, soil conservat...
Article
Sediment transport from agricultural land into rivers and reservoirs is a problem within the Czech Republic. This problem was highly accelerated almost 50 years ago during the communist period. At that time strong collectivization was undertaken leading to destruction of traditional landscape patterns, surface outflow, erosion processes intensifica...
Article
Full-text available
At present, the landscapes in the former communist countries of Eastern Europe are undergoing a second major change in 50 years. After World War II, collective agricultural systems, such as the United Agricultural Cooperatives and the State Farms, were established. Following the example of the Soviet Union, individual fields were put together in or...