Long term changes in water areas and wetlands in an intensively farmed landscape: A case study from the Czech Republic

Abstract

Abstract:The landscape of the Czech Republic currently faces droughts that are caused by several factors. One of the reasons for drought is landscape development and land cover changes. Changes in water and wetland areas and streams were studied by comparing old military maps and the present state. Water and wetland areas in fertile lowlands significantly decreased over time; the landscape was continuously dried out with the aim of increasing agricultural and woody production. While water and wetland areas occupied nearly one-third of the study area (Nové Dvory and Žehušice micro-regions in Central Bohemia) at the end of the 18 th century, the present share of these areas is only 3.5%. There was a decrease of approximately 10% in each period, and nearly all of these areas disappeared by the end of the 19 th century. Water and wetland areas were changed primarily to arable land. The length of streams decreased by the end of the 19 th century. Drainage and irrigation channels were built during the 20 th century, and although they are only periodic or episodic streams, these channels increased the total length of streams.Key words: streams, still waters, wetlands, land use changes, drought, central Europe Abstrakt: Krajina České republiky v současnosti čelí nebezpečí sucha, které je způsobeno mnoha faktory. Mezi ně patří změny krajiny a krajinného pokryvu. V článku jsou sledovány změny vodních a mokřadních ploch a délky vodních toků na podkladě starých vojenských mapování a současného stavu. Vodní a mokřadní plochy v nížinách zásadně ubyly a krajina byla vysušována s cílem zvýšit zemědělskou a lesnickou produkci. Zatímco na konci 18. století vodní a mokřadní plochy zaujímaly skoro třetinu sledovaného území Novodvorska a Žehušicka ve středních Čechách, v současnosti je to jen 3,5 %. V každé ze sledovaných period ubylo přibližně 10 % jejich rozlohy, významný úbytek těchto ploch v krajině tak nastal již v 19. století. Vodní a mokřadní plochy byly změněny převážně na ornou půdu. Délka vodních toků poklesla zejména v průběhu 19. století. Současná data ukazují nárůst jejich délky, který je ale způsoben budováním zavodňovacích a odvodňovacích kanálů, jejichž délka je také započítána do celkové délky vodních toků, byť nejsou celoročně protékány vodou.

Envisioning Present and Future Land-Use Change under Varying Ecological Regimes and Their Influence on Landscape Stability

“…Changed polygons indicate the pressure of outer drivers, namely, population growth, agricultural intensification, or even land abandonment. Again, analysis of landscape trajectories adopts a more qualitative representation of spatial data, whereas areas with the same land cover class can be thematically separated following different land-use classes and land cover history [128,129]. This approach provides us with a tool which allows a refined interpretation of ongoing landscape changes and their ultimate drivers [109].…”

“…Croplands with water deficit have been more or less intensively irrigated. Irrigation is not only a serious driver of water consumption [129,140,151] but can also cause salinization of soils, leading to biomass reduction and susceptibility to erosion [152]. Construction of massive drainage systems in wetlands and wet meadows has been observed in Czech Republic, mainly in the 1970s and the 1980s [153].…”

Discovering extinct water bodies in the landscape of Central Europe using toponymic GIS

“…Those that survive can play an important part in ecology (Jeffries, 1991) and hydrology (Smith et al, 2002), as well as in cultural terms (Rees, 1997). The restoration of some extinct fishponds, which could help maintain water in the agricultural landscape (David and Davidová, 2015), is being discussed in relation to increasing anthropogenic pressures on the landscape and their negative impact on its ecology and water capacity (Bastian et al, 2006;Šantrůčková et al, 2017), together with the changing climate and the increased probability of extreme hydrological phenomena (droughts) (Zahradníček et al, 2015).…”

“…Many studies apply the set of current and old maps for this purpose (e.g. Havlíček et al, 2014;Skaloš et al, 2011;Šantrůčková et al, 2017). These are mainly regional studies, however, as processing an area the size of a country is very demanding time-and capacity-wise (Pavelková et al, 2016).…”

Analysis of Flood Hydrographs in Order to Predict the Shape of Their Falling Limbs

“…Besides big dams, small water reservoirs spread in the landscape are intended to be a part of complex approach to increase water retention in the landscape. The reason is, among other things, the loss of these water bodies in the past [6,7]. The proper function of these structures which are listed as an important landscape element in the Act on the conservation of nature and landscape [8] is highly dependent on the hydrological regime.…”