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Water retention in the landscape is discussed in the context of conservation and improvement of both its productive and non-productive functions. We analysed the retention potential of a small agricultural catchment associated with the Bílý potok brook, investigating the possibility to improve its retention capacity and slow down the surface runoff, thus increasing the underground water resources. Method of curve numbers was used for that purposes. From results, it emerged that present maximum water retention in the Bílý potok catchment is 96.2 mm. It could increase by 101.3 mm in case of grassing about 20% arable land threatened by soil erosion. As next possibility to retain water from precipitations in landscape, capacity and transformation effect of reservoirs designed in master plans was analysed. The latest programming tools working in the GIS environment were used to assess the retention capacity of both the catchment surface and the reservoirs. Analysing master plans in the catchment, it was found that 16 designed water reservoirs (from 31) have a good potential to intercept water and transform flood discharges. In the result, priority for building of reservoirs was recommended according to their pertinence and efficiency in the studied catchment. Presented complex approach can be widely implemented, especially for better effectivity and cohesion of landscape planning and land consolidations processes.

Snížení vstupů dusíku a fosforu do povrchových vod z plošných zemědělských zdrojů vyžaduje cílené uplatňování diferencovaných opatření. V rámci studie zaměřené na ochranu půdy a vody v povodí Jihlavy nad vodním dílem Dalešice byly identifikovány oblasti s potenciálním rizikem vodní eroze, zrychlené infiltrace a vyplavování živin, odvodněné plochy a ohrožené příbřežní zóny vodních útvarů. Následně byl pro toto povodí navržen systém komplexních opatření ve více variantách a jejich účinnost byla odhadnuta pomocí jednoduchých empirických modelových výpočtů a na základě výzkumných poznatků. Realizace opatření obsažených v optimální variantě 3 by mohla v zájmovém povodí vést k omezení dopadů vodní eroze na kvalitu povrchových vod o 26,5 %, současně se snížením objemu vyplavovaného celkového dusíku o 22,8 %. Výsledky studie jsou dílčí součástí Jakostního modelu povodí Jihlavy a byly poskytnuty k využití Kraji Vysočina a Státnímu pozemkovému úřadu.

In the Czech Republic, a significant amount of agricultural landscape nutrients is swept away by surface washes and leakages to subsoil. Subsequently there is a negative influence on surface water quality, where of course also point sources of pollution participate in. Flowing surface water often becomes stagnant while the certain self-purifying processes proceed both in the flowing and stagnant waters. It can be simultaneously stated that the self-purifying process is practically uncontrollable, primarily due to the impact of many entering factors. One of the environmental and technical elements providing quality improvement of water running off a water reservoir is deployment of constructed floating wetlands (CFW). The theoretical background, as well as the laboratory measurements carried out on the test land of the Brno University of Technology in experimental tanks, evidence the significant treatment efficiency of the CFW. Within the research activities, we focused on the general pollution parameters set for surface waters. The first results show that the total phosphorus concentration removal efficiency is 38.8 % after 22 days with employment of the CFW which is a considerably higher value compared to the lysimeter with no CFW where the removal efficiency was only 4.37 %. The results can be large-scale applied to most of the small water reservoirs situated in the agricultural landscape. [ABSTRACT FROM AUTHOR]

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Research on the influence of land use changes and erosion and flood control measures on a reduction of harmful effects of extreme rainfall-runoff events has occourred at the experimental Němčický stream basin since 2005. It has been documented by obtained results of rainfall and discharge gauging and by water sample analyses that sediment transport significantly corresponds with the cover efficiency of agricultural crops. Based on the analysis of particular comparable rainfall-runoff episodes, it can be stated that the protection (e.g. grassing, growing of narrow-row crops) of slopes adjacent to watercourses has a crucial influence on the reduction in surface water pollution with insoluble substances. In such cases the efficiency of grass cover is 90-99% compared to bare soil, while the efficiency of narrow-row crops is 50-80% in comparison with bare soil. The efficiency of narrow-row crops at the time of maximum vegetation stand is close to that of permanent grasslands. [ABSTRACT FROM AUTHOR]

Copyright of Listy Cukrovarnicke a Reparske is the property of VUC Praha a.s. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)