Water quality of the Cidlina river (right tributary of the Labe river was studied during two years (1997 - 1998). Besides the examination of hydrology and land use, the main resources of pollution were identified. Physical, chemical and biological parameters of water were measured in 10 profiles and water quality was evaluated according to Czech norms 75 7221 and put into the grade of purity. Pollution of upper part of river is not so bad but lower part is very polluted. High concentration of BOD5 correspond with biological parameters - alfa-mesosaprobita. At the end some tools and strategies are added to manage water more effectively. and V létech 1997 a 1998 byla sledována kvalita povrchové vody v Cidline (pravostranný přítok Labe). Kromě studia hydrologických parametrů a využívání krajiny (land use) byly zjištěny hlavní zdroje znečištění - města Jičín a Nový Bydžov. Fyzikálně-chemické a biologické charakteristiky vody byly měřeny na 10 říčních profilech a kvalita vody hodnocena podle CSN 75 7221 a zařazena do tříd čistoty. Horní část toku, méne znečištěná, náleží do III. - IV. třídy, silně znečištená dolní část do V. třídy čistoty. Zvýšené koncentraci BSK5 v celém toku odpovídá i kvalita makrozoobentosu - vetšinou α -mezosaprobita. V závěru jsou navržena opatření k zlepšení kvality vody.
The main trends in spontaneous regeneration were studied in old-fields in the Transylvanian Lowland (Câmpia Transilvaniei) over a period of 40 years using the chronosequence method. Succession proceeds to grassland, because the establishment of woody vegetation is hindered by grazing and mowing of the old- fields and by the scarcity of woodlands in the vicinity. Community properties and population-level changes were recorded at different stages of succession and compared with semi-natural grassland in the surrounding landscape. Due to favourable soil conditions and temperate climate, vegetation cover develops quickly after the fields are abandoned. Annuals dominated only in the first year. After two years the fast growing clonal grass, Elymus repens, became dominant. After approximately 12 years, Elymus was replaced by Festuca rupicola, which is more resistant to stress and disturbance. In the later stages of succession various species, some typical of surrounding grassland, attained high cover values. A steady increase in species diversity, measured by the Shannon index, and richness was recorded at both the field (1.0–2.5 ha) and plot (4 × 4 m) scales. Species richness increased rapidly in early and middle stages and stabilized after the 14th year. Specific features of the succession in the old-fields in the Transylvanian Lowland can be attributed to the continued grazing and mowing of the fields after they are abandoned. This increases species richness because it arrests succession at a stage when species diversity is high. The management directs regeneration towards secondary grassland rather than species poor woodland.
The changes of runoff in the middle reaches of the Yellow River basin of China have received considerable attention owing to their sharply decline during recent decades. In this paper, the impacts of rainfall characteristics and land use and cover change on water yields in the Jingle sub-basin of the middle reaches of the Yellow River basin were investigated using a combination of statistical analysis and hydrological simulations. The Levenberg Marquardt and Analysis of Variance methods were used to construct multivariate, nonlinear, model equations between runoff coefficient and rainfall intensity and vegetation coverage. The land use changes from 1971 to 2017 were ascertained using transition matrix analysis. The impact of land use on water yields was estimated using the M-EIES hydrological model. The results show that the runoff during flood season (July to September) decreased significantly after 2000, whereas slightly decreasing trend was detected for precipitation. Furthermore, there were increase in short, intense, rainfall events after 2000 and this rainfall events were more conducive to flood generation. The “Grain for Green” project was carried out in 1999, and the land use in the middle reaches of the Yellow River improved significantly, which make the vegetation coverage (Vc) of the Jingle sub-basin increased by 13%. When Vc approaches 48%, the runoff coefficient decreased to the lowest, and the vegetation conditions have the greatest effect on reducing runoff. Both land use and climate can change the water yield in the basin, but for areas where land use has significantly improved, the impact of land use change on water yield plays a dominant role. The results acquired in this study provide a useful reference for water resources planning and soil and water conservation in the erodible areas of the middle reaches of the Yellow River basin.