INTRODUCTION \u2013 PAST AND PRESENT ACTIVITIES IN THE V\u00ddROVKA RIVER BASIN<\/h2>\n
In the past, several expert articles were published about the V\u00fdrovka river basin, dealing mainly with historical development of the landscape and change of land use, or the changing location of wetland habitats [1\u20133]. Part of the V\u00fdrovka river basin was chosen as one of the sites analysing the change of wetlands in the landscape of lowlands and hills of the Czech Republic [4]. Recently, on the initiative of the Central Bohemian Region and with support from the Operational Programme Environment, a\u00a0study of runoff conditions and proposals for possible flood control measures in the V\u00fdrovka river basin was completed [5, 6]. The Local Action Group (LAG) Podlipansko, o. p. s., [5, 7] significantly participated in the implementation of this study. The above articles and the current study show that the V\u00fdrovka river basin is a\u00a0suitable model area for proposing measures to improve water retention in the landscape, representing densely populated and intensively agriculturally used areas of Central Bohemia, specifically the Elbe river basin.<\/p>\n
For the needs of other projects, a detailed analysis of the area presented in this article was performed. Currently, the V\u00fdrovka river basin is used as a model river basin to identify the origin of pollution sources for selected indicators causing failure to achieve good surface water status according to Directive 2000\/60\/EC of the European Parliament and of the Council (Water Framework Directive) in the TA CR project SS02030027 \u201dWater systems and water management in the Czech Republic in conditions of climate change\u201d. Within this project, in 2021\u20132022, selected\u00a0 environmental components are monitored in the V\u00fdrovka river basin and, based on this monitoring and other available data, the significance of individual pollution sources and pollution routes for this river basin will be evaluated and general conclusions drawn; if needed, the follow-up monitoring programme will also be updated.<\/p>\n
V\u00ddROVKA RIVER BASIN<\/h2>\n
The V\u00fdrovka river basin is located in the Central Bohemian Region in the districts of Kutn\u00e1 Hora, Kol\u00edn, Nymburk, and Praha-v\u00fdchod. In terms of altitude, the area extends between 175\u2013555 m a.s.l. The V\u00fdrovka springes at 493 m a.s.l. near Koch\u00e1nov (part of Uhl\u00ed\u0159sk\u00e9 Janovice); other significant watercourses in the basin are the Be\u010dv\u00e1rka, rising near Milet\u00edn at 440 m a.s.l., and the \u0160embera, rising near Vy\u017elovka at 404 m a.s.l. The confluence of the V\u00fdrovka and Be\u010dv\u00e1rka is in the area of Zale\u0161any-\u017dabonosy-Pla\u0148any, at an altitude of 219 m. This is followed by the confluence of the V\u00fdrovka and \u0160embera at 184 m a.s.l. near the village of Zv\u011b\u0159\u00ednek; after 3.5 km, near the village of P\u00edsty, the V\u00fdrovka flows into the Elbe at an altitude of 175 m [8] (Fig. 1<\/em>).<\/p>\n The entire territory of V\u00fdrovka 3rd order basin 1-04-06 is located in the Elbe basin at the boundary of the Lower Vltava and Upper and Middle Elbe sub-basins. According to ZABAGED\u00ae land cover classification [9], arable land (67.74\u00a0%) prevails in the V\u00fdrovka 3rd order basin 1-04-06; a\u00a0significant part is also covered by forests (16.20\u00a0%) and other agricultural areas (10.74\u00a0%). In contrast, the representation of water bodies and wetlands is marginal (0.74\u00a0% and 0.07\u00a0%, respectively). Built-up and artificial areas cover 4.51\u00a0% of this basin.<\/p>\n In terms of landscape cover within the river basin, arable land is most represented in the Be\u010dv\u00e1rka river basin (78.89\u00a0%); in the V\u00fdrovka and \u0160embera river basins it is 67.85\u00a0% and 63.79\u00a0%, respectively. Forests occupy the largest area in the \u0160embera and V\u00fdrovka river basins (especially in higher altitudes and spring areas): 19.36\u00a0% and 15.57\u00a0%, respectively; it is 9.75\u00a0% in the Be\u010dv\u00e1rka river basin. Other agricultural areas and built-up areas show a\u00a0similar relative composition within individual river basins. The least abundant (but for the landscape very important) types of land cover, i.e. water bodies and wetlands, occur most in the Be\u010dv\u00e1rka river basin. In the remaining two river basins, the representation of water bodies differs; it is higher in the V\u00fdrovka river basin, while wetlands occur more often in the \u0160embera river basin (Tab. 1<\/em>; Fig. 2<\/em>).<\/p>\n In the entire V\u00fdrovka 3rd order basin 1-04-06, there are six types of landscapes according to the typology of the current landscape of the Czech Republic. Three general types of natural landscapes and three functional landscape types. There are a\u00a0total of three general types of natural landscapes in the catchment area. The source areas of the V\u00fdrovka and also partly the Be\u010dv\u00e1rka are in a\u00a0slightly cool landscape of hills and highlands, the upper part of the V\u00fdrovka, Be\u010dv\u00e1rka and \u0160embera river basins, including the spring area, are in moderately warm landscapes of basins and hills, and the rest of the whole basin is located in warm lowlands. There are also a\u00a0total of three functional landscape types in the catchment area. The source areas of the V\u00fdrovka, and partly also the Be\u010dv\u00e1rka and the upper part of the \u0160embera river basin, are in the forest-field landscape; the source parts of the \u0160embera river basin are located in the field landscape with forests and heterogeneous agricultural areas. The rest of the whole river basin falls within the field landscape [10].<\/p>\n Geologically, the entire V\u00fdrovka river basin is part of the Bohemian Massif. The geological composition of the area is relatively diverse, while the geological interfaces do not correspond exactly to the hydrological watersheds.<\/p>\n The subsoil of the upper and middle V\u00fdrovka is mainly part of the Kutn\u00e1 Hora crystalline basement of the Kutn\u00e1 Hora-Svratka region. The rocks of the\u00a0Kutn\u00e1 Hora crystalline basement are represented mainly by orthogneiss to migmatites, mica-schists to schist gneisses, etc. To a\u00a0lesser extent, there are also more subsilicic metamorphic rocks, such as serpentinites (body near Be\u010dv\u00e1ry), amphibolites, and similar rocks.<\/p>\n The subsoil of the upper and middle \u0160embera are of the Permocarbon structure of Blanick\u00e1 br\u00e1zda, the southwestern part is of the Central Bohemian pluton. The sedimentary filling of the Blanick\u00e1 br\u00e1zda consists mainly of breccias, conglomerates, sandstones, arkoses, siltstones, and claystones. The Central Bohemian pluton is mainly represented by biotite granite from \u0158\u00ed\u010dany.<\/p>\n Denudation relicts of sediments of the Czech Cretaceous Basin occur on older rocks in the V\u00fdrovka and \u0160embera river basins. Sedimentation began with the Peruc\u2013Korycany Formation of the Cenomanian age. Locally, there are basal Peruc layers, which are mainly composed from sandstones, siltstones, claystones, and conglomerates. The overlying Korycany strata are formed mainly by marine sandstones. Above them, the marine sediments of the B\u00edl\u00e1 Hora Formation of the Lower Turonian age have been preserved, consisting of marlstones, claystones, limestones, spiculites, calcareous sandstones, and siltstones. The thickness of Upper Cretaceous sediments generally increase from south to north. The confluence area of the V\u00fdrovka and \u0160embera is thus built of Czech Cretaceous Basin rocks; the underlying older rocks no longer rise to the surface. The highest member of the Upper Cretaceous sedimentation is represented by the denudation relics of the Jizera Formation of Middle Turonian age, especially kaolinic sandstones, marlstones, and limestones.<\/p>\n The surface of both compared river basins is covered by Quaternary sediments. Pleistocene Aeolian sediments \u2013 loess and loess clays are significantly represented. Especially in the north of the area there are Pleistocene fluvial sandy gravels of river terraces. Diluvium\u2019s\u00a0are very widespread \u2013 diluvial aluminous-sandy and aluminous-stone sediments. There are also anthropogenic deposits, such as material from construction and landfilling [8, 11].<\/p>\n From the hydrogeological point of view, the area of interest is part of the hydrogeological regions of the base layer 6531 \u2013 Kutn\u00e1 Hora crystalline basement, 4350 \u2013 Velim Cretaceous and 4360 \u2013 Elbe Cretaceous. In the northern part of the area of interest, there is the Upper Layer District 1152 \u2013 Elbe Quaternary up to Nymburk.<\/p>\n The upper and middle basin of the V\u00fdrovka form hydrogeological district 6531 \u2013 Kutn\u00e1 Hora crystalline basement. The crystalline rocks have slight fracture permeability. From the hydrogeological point of view, the shallow aquifer in the Quaternary sediments and the zone of subsurface disengagement of rock fractures is dominant in the area of interest with the crystalline bedrock. The area is usually only suitable for smaller groundwater abstraction for local supply.<\/p>\n The upper and middle basin of the \u0160embera are mostly part of the hydrogeological district of the base layer 4350 \u2013 Velim Cretaceous. Most of the subsoil of the area consists of Permocarbon sediments of the Blanick\u00e1 br\u00e1zda. These are characterized by irregular alternation of aquitards and collectors with fracture and intrinsic permeability and are generally more permeable than crystalline basement in the V\u00fdrovka river basin.<\/p>\n Of the overlying relics of Cretaceous sediments, psammitic Cenomanian sediments tend to be very permeable. They occur either as denudation relics alone or are partially covered by younger formations of the Czech Cretaceous Basin. The most widespread collector of the area of interest is the so-called basal Cretaceous collector, from which groundwater is locally obtained for the municipality needs.<\/p>\n Another very permeable environment is the fluvial psammitic sediments of river terraces and floodplains of larger streams. Groundwater is pumped from them for smaller villages in the area. Other Quaternary sediments are less permeable, such as loess, diluviums, and flood clays. Some of them have the character of local aquitards.<\/p>\n The confluence area of the V\u00fdrovka and \u0160embera is in the hydrogeological district of the base layer 4360 \u2013 Elbe Cretaceous and to Upper Layer District 1152 \u2013 Elbe Quaternary up to Nymburk. From a\u00a0hydrogeological point of view, the area is generally much more permeable than the upper and middle parts of the V\u00fdrovka and \u0160embera river basins. This is mainly due to the highly permeable fluvial gravel and sands of river terraces, which cover most of the area. The height of the groundwater level in this basin depends on the morphology of the terrain, local permeability, and precipitation totals. In general, the water level at higher elevations is the deepest, and in valleys near watercourses it is closer to the surface.<\/p>\n Regarding the occurrence of a significant amount of groundwater, the crystalline basement in the upper and middle catchments of the V\u00fdrovka and \u0160embera is rather a deficit area. Better conditions are found within the denudation relics of the Cretaceous sandstones, more permeable Quaternary sediments along watercourses, and in the Permocarbon rocks of Blanick\u00e1 br\u00e1zda. The confluence area of the V\u00fdrovka and \u0160embera has the best conditions\u00a0for concentrated abstraction of higher amounts of groundwater; this is due to important collectors in the Quaternary gravel of river terraces and in the Cretaceous sandstones [8, 11\u201314].<\/p>\n Soil conditions in the entire V\u00fdrovka river basin are very diverse; there is a\u00a0wide range of soil types (Fig. 3<\/em>). In the immediate vicinity of the watercourses, there are mainly:<\/p>\n In the wider vicinity of the rivers in the basin, these are:<\/p>\n![\"\"](\"https:\/\/www.vtei.cz\/wp-content\/uploads\/2022\/06\/Richter-1-1.jpg\")
<\/a><\/strong><\/p>\nFig. 1. The 3rd order V\u00fdrovka river basin in terms of hydrology and altitude \u2013 data source [8]<\/h6>\n
HYDROLOGY<\/h2>\n
\nIt covers 542.5 km2 and consists of 54 river basins of the 4th order (hydrological basin \u2013 HLGP). However, from the point of view of hydrology, this river basin can be divided into two, or even three, parts. There are two main watercourses in the V\u00fdrovka river basin: the V\u00fdrovka and \u0160embera. The \u0160embera should, according to most characteristics, form a separate river basin; but they have a common river basin due to the fact that the \u0160embera flows to V\u00fdrovka 3.5 km before V\u00fdrovka enter the Elbe, where both watercourses fall within 5th order of watercourses according to Strahler. The V\u00fdrovka has as a significant right-bank tributary, the Be\u010dv\u00e1rka, which flows into the V\u00fdrovka before Pla\u0148any, at its 23.2 river km. According to the Strahler order of watercourses, at the confluence the V\u00fdrovka is in the 5th order and Be\u010dv\u00e1rka in the 4th order. From this point of view, the V\u00fdrovka 3rd order basin 1-04-06 can be divided into three parts: the V\u00fdrovka basin, consisting of 31 HLGPs with an area of 289.1 km2; the Be\u010dv\u00e1rka basin, consisting of 7 HLGPs with an area of 64.3 km2; and the \u0160embera basin, consisting\u00a0of 16 HLGPs with an area of 189.1 km2. The length of the V\u00fdrovka watercourse is 61.8\u00a0km, the Be\u010dv\u00e1rka 22.9 km, and the \u0160embera 28.2 km; the V\u00fdrovka watercourse in its upper part and the entire Be\u010dv\u00e1rka watercourse are significantly more fragmented than the \u0160embera watercourse [8] (Fig. 1<\/em>).<\/p>\nLANDSCAPE COVER AND TYPOLOGY OF THE CURRENT LANDSCAPE OF THE CZECH REPUBLIC<\/h2>\n
<\/a><\/strong><\/p>\nFig. 2. Map of land cover in the 3rd order V\u00fdrovka river basin \u2013 data source [9]<\/h6>\n
Tab. 1. Representation of land cover classified according to ZABAGED\u00ae [9] in individual parts of the catchment area of the 3rd order V\u00fdrovka river basin<\/h5>\n
<\/a>\nGEOLOGY<\/h2>\n
HYDROGEOLOGY<\/h2>\n
\nThe second important aquifer is the basal Cretaceous aquifer in the Cenomanian sandstones. In contrast, less permeable rocks form (semi) aquitards here, such as marlstones and Turonian claystones, flood clays, and loess; these are not very favourable for the formation and circulation of groundwater [8, 12\u201314].<\/p>\nGROUNDWATER \u2013 SUMMARY<\/h2>\n
PEDOLOGY<\/h2>\n
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