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Hydric potential of selected river basins in Slovakia
Ecohydrology & Hydrobiology 13 (2013) 201–209
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Original research article
Hydric potential of selected river basins in Slovakia Toma´sˇ Lepesˇka a,b,* a
Department of Applied Ecology, Faculty of Ecology and Environmental Sciences, Technical University in Zvolen, T. G. Masaryka 2117/24, 960 53 Zvolen, Slovakia b Institute of Landscape and Regions Research, Department of Science and Research, Matej Bel University in Banska´ Bystrica, Cesta na amfitea´ter 1, 947 01 Banska´ Bystrica, Slovakia
A R T I C L E I N F O
A B S T R A C T
Article history: Received 6 March 2013 Accepted 22 August 2013 Available online 5 September 2013
Landscape attributes affect the quantity, quality, distribution and accessibility of water resources. Except for fixed and hardly impacted environmental characteristics affecting the hydric potential of the landscape, it is possible by optimal land use planning and management to modify its ability to infiltrate and detain precipitation. The use of landscape characteristics as an efficient tool in river basin management can improve disturbed conditions in catchments. In this paper, we have focused on the evaluation of the hydric potential of six river basins in Slovakia. Assessing the most relevant landscape attributes in relation to the protection of water resources, we have identified areas with various landscape hydric potentials (LHPs), which should be taken into consideration when developing a river basin management plan. The spatial distribution of LHP categories undermines the customary view that the landscape’s ability to infiltrate and retain water is affected by only some of the physical–geographic attributes (frequently presented as hydrogeological bedrock and soil characteristics). The LHP distribution in model catchments is explained through specific combinations of factors having the greatest influence. ß 2013 European Regional Centre for Ecohydrology of Polish Academy of Sciences. Published by Elsevier Urban & Partner Sp. z o.o. All rights reserved.
Keywords: Hydric potential Landscape Integrated river basin management Water resources Slovakia
1. Introduction Water as an integrating element interconnects other elements and components of the environment. The number of water resources, their quality, accessibility and distribution, as well as their ecosystem processes, is bound to climatic, abiotic and biotic factors that predetermine their management based on a holistic approach. The holistic approach presenting the idea that ‘‘the whole is more than its individual parts’’ establishes integrated river basin management as the basis of contemporary perceptions of water sources and the landscape. It points to the fact that water resources cannot be managed individually or through individual landscape attributes,
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such as vegetation, soil, etc., but refers to the necessity of a water basin management perspective that considers all the crucial elements of the water – landscape system as a whole. From the perspective of the socio-economic field, it also implies the idea of managing and adopting an equitable approach to water and other natural resources as well as all the other ecosystems within the river basin. 1.1. Ecohydrology principles in landscape’s hydric potential Interactions between precipitation (water) and landscape attributes are variable. Variability is imposed by local conditions within a catchment which can be constant (e.g. slope inclination, soil texture, etc.) or changing (present hydrometeorological conditions, catchment saturation state, land use, soil ice, etc.). For evaluating the landscape or ecosystem effect on the quality, quantity, distribution and accessibility of water resources there is a
1642-3593/$ – see front matter ß 2013 European Regional Centre for Ecohydrology of Polish Academy of Sciences. Published by Elsevier Urban & Partner Sp. z o.o. All rights reserved. http://dx.doi.org/10.1016/j.ecohyd.2013.08.004
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need to determine the physical and geographical attributes that are crucial within the water-landscape complex. Since infiltration, retention and runoff are determined by a complex of factors which can also act contrarily, the effect of a particular landscape attribute can be very specific. The determining physico-geographical factors are bedrock transmissivity (Bear, 1988); an average annual precipitation amount; an average annual amount of evapotranspiration; geomorphologic conditions (Zachar, 1982); soil textures and types (Leeper and Uren, 1993); the composition, structure, stability, originality and health condition of forest stands – that results in their ecological stability (Maser and Trappe, 1984; Chang, 2003); and the characteristics, structure and intensity of land use (Peck and Wiliamson, 1987; Dale, 1996; Gordon et al., 2008). Their mutual interactions, synergistic or antagonistic, determine the resultant effects of the landscape (ecosystems) on water resources. The fact, that ecosystem management can influence hydrologic processes or vice versa – that biological processes can be managed by the hydrological parameters, led to the formulation of the paradigm of landscape management called ecohydrology (Zalewski, 2000). Ecohydrological hypotheses are particularly focused on managing both the quality and the number of water resources by means of increasing the resistance, resilience and inhibiting ability of river ecosystem biota to change, as well as to other biological characteristics of river corridors (Zalewski et al., 1997; Zalewski, 2000). To a certain extent, it lacks the emphasis on integration by considering key elements of the river basin, such as soil, relief characteristics, hydrogeological conditions and the use of the forested and non-forested landscape as well as climatic conditions. On the basis of the ecohydrological hypotheses and through river basin attribute assessment, we can define a landscape’s hydric potential (Lepesˇka, 2010a, 2010b). The landscape’s hydric potential (LHP) refers to the ability of the landscape to decelerate and detain precipitation and the capability of the water to infiltrate into ground. Temporary detention of water on/in vegetation, in the humus layer, soil, and bedrock, and in micro-depressions also can be understood under this term. It is the influence of various elements and components of the landscape on the amount, quality, distribution and accessibility of water resources. Based on the LHP, we can objectively consider the regions where it is possible to keep the current way of using the landscape and those in which it is necessary to design a new approach. It is obvious that good water resources can be achieved by managing ecosystems and human activities in an appropriate way, which is one of the main requirements arising from the Water Framework Directive (Directive 2000/60/EC, 2000). The effort of decision-making authorities should primarily lead to the increase of the landscape’s hydric potential. That can be accomplished by the optimal structuring of the landscape, appropriate management of its natural resources and economical management of current and planned socio-economic activities within river basins. The use of landscape (ecosystem) characteristics as an efficient tool in river basin management can lead to water
retention within landscape (Zalewski and Wagner, 2005), transformation of unwanted surface run-off into subsurface storage (Sˇa´ly and Midriak, 1995), an increase in the quality of water resources (by reduction of nutrient input, denitrification and filtration) (Falkenmark and Rockstro¨m, 2006), protection of water, soil and the food chain from hazardous element contamination and increase the water amount in watercourses. The advantages of optimal water basin management can be far wider. It can increase underground water storage, reduce stream flooding and, in the broadest consequence, raise the quality of life and increase aesthetic values and the health of the population in urban ecosystems (Zalewski and Wagner, 2005). Marsalek et al. (2006) have recently shown that the implementation of an ecohydrology approach can eliminate flood hazards in the urban landscape. The LHP is a result of the interaction of all relevant river basin attributes. Some authors give a special emphasis to particular physical and geographical components like bedrock transmissivity, soil texture (Holko, 2010; Solı´n, 2011) or forest cover (Liniger and Weingartner, 1998) when evaluating infiltration. The aim of this paper is to identify the LHP of six selected river basins and to determine the different ecosystem attributes that influence the infiltration, deceleration and detention of precipitation. Our purpose is to describe how the LHP changes in heterogeneous river basins when evaluated using the same attributes. By comparing the LHPs, the optimal management strategy for a specific partial river basin can be suggested and its function within the system of the main watercourse or coastal drainage area can be defined. We focused on basins situated in heterogenic natural conditions which consisted of mountain and submontane regions to a large extent. The quality, amount, accessibility and distribution of water resources in the lower elevation regions depend on the usage intensity in the upper parts of the river basins. This interconnection of needs between users of natural resources in both the upper and lower river basins, along with their often contradictory demands on environmental and natural resources, shows the importance of negotiations among all the parties engaged in the hydrological cycle. 2. Materials and methods 2.1. Description of the model river basins The experimental areas were chosen as follows: (1) the upper Va´h River basin (the Va´h River basin down to its confluence with the Orava River at Kral’ovany), (2) the Kysuca River basin, (3) the upper part of the Laborec River basin (the area of the Laborec River basin down to its confluence with the Cirocha River near Humenne´), (4) part of the Topl’a River basin (the Topl’a River basin down to its confluence with the Radomka River near Giraltovce), (5) the upper part of the Torysa River basin (down to Presˇov) and (6) the upper part of the Hron River basin (down to the mouth of the Hutna´ River above the village of Lucˇatı´n). The location of experimental river basins within Slovakia is
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shown in Fig. 1. The river basins were chosen to represent various physical geographic characteristics of mountain and submontane river basins in Slovakia. These river basins are left-hand tributaries of the Danube River. Their areas varied from 732 to 2272 km2 and the catchments are situated within an elevation range of 150–2494 m a.s.l. with an average annual precipitation of 700 mm in the lowest parts and 2000 mm in the upper parts. Predominating bedrock is flysch together with Mesozoic and Palaeozoic rocks on which has developed mostly loamy soils and sandy loams or loamy sands. Forest stands are the prevailing type of land cover varying from 41 to 66% of areal coverage. In describing these areas, we focused on their environmental features which influence the overall landscape’s hydric potential to a significant extent. These features included: transmissivity of bedrock; average annual precipitation levels; average annual potential evapotranspiration levels; slope inclination conditions of the areas; soil types and textures; the composition, structure, condition, stability and originality of the forest stands; and the characteristics, structure and usage intensity of non-forested landscapes. The aggregated physical catchment descriptors for all subbasins are listed in Table 1, which shows a strong heterogeneity including a wide range in the geological, pedological, topographical, land use and climate conditions. 2.2. Methods To identify the landscape’s hydric potential of the chosen river basin areas, we used the methodology according to Lepesˇka (2010b). It is based on the assessment of the average amount of precipitation in a particular river basin and on landscape attributes influencing runoff infiltration, deceleration and retention. Each landscape attribute was assessed according to its quality, or more precisely its exceptionality. The methodology results in LHP grades for each of the modelled river basins.
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Subsequently, the grades were classified into five categories (Table 2) and will be used as the basis for formulating optimal river basin management strategies. The reference materials used to identify the hydric potential of the modelled river basins were as follows: land cover data (CORINE Land Cover) provided by Slovak Environmental Agency (SEA, 2004), data from forest management plans (on the ecological stability level of the forest stands) provided by National Forest Centre in Zvolen, map and cartographic data taken from Landscape Atlas of the Slovak Republic (Miklo´s and Hrncˇiarova´, 2002), data on Slovak digital relief in raster format with 50 m resolution (GeoModel, 1999) and base maps of the Slovak Republic at the scale of 1:10,000. When necessary, the data were refined and updated using field investigations. The analysis, processing, and synthesis of the reference materials, and the evaluation and creation of the maps of hydric potential model river basins were realized using the GIS software of ArcView 3.2 and ArcGis 9.3. 3. Results and discussion 3.1. Landscape’s hydric potential The outcome of landscape’s hydric potential evaluation of the modelled river basins was the establishment of LHP grades and their subsequent categorization into five categories according to their potential to infiltrate and retain precipitation. The areas classified into the first and second categories of LHP were ranked as the most significant. Depending on their size, compactness and distribution within the river basin, the overall significance of the studied areas for water resources management was developed. The percentage of LHP categories in the modelled river basins in the Slovak Republic is shown in Table 3, with their spatial distribution shown in Figs. 2 and 3. The best landscape’s hydric potentials (the localities classified in the first two categories) were in the upper Va´h,
Fig. 1. Distribution of model river basins in Slovakia.
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Table 1 Physical and geographical attributes of the model river basins affecting the spatial variability LHP. Srb (km2)
Bedrock composition
Ss
St
Si (8)
ESL of forest ecosystems
Land cover
P (mm)
E (mm)
T
Va´h (430–2494)
2272.5
Mesozoic era (45%); flysch (28%); igneous rocks (15%)
Loamy soils (45%); Sandy loams (35%); Loamy sands (11%)
RA (30%) CM (30%) PZ (20%)
0–7 (22%) 7.1–18 (27%) 18 (50%)
Very great (10%); Great (46%); Lowered (44%)
Forest stands (60%); Agricultural landscape (30%); Urban and industrial areas (4%) Forest stands (57%); Agricultural landscape (40%); Urban and industrial areas (3%) Forest stands (66%); Agricultural landscape (31%); Urban and industrial areas (3%) Forest stands (46%); Agricultural landscape (47%); Urban and industrial areas (7%)
Min. 700 Max. 2130
Min. 300 Max. 600
High (23%) Moderate (46%) Low (31%)
Min. 800 Max. 1600
Min. 350 Max. 500
High (25%) Moderate (55%) Low (20%)
Min. 700 Max. 1200
Min. 400 Max. 600
High (22%) Moderate (72%) Low (6%)
Min. 550 Max. 1000
Min. 400 Max. 650
High (4%) Moderate (87%) Low (9%)
Forest stands (41%); Agricultural landscape (55%); Urban and industrial areas (4%) Forest stands (61%); Agricultural landscape (21%); Urban and industrial areas (3%)
Min. 700 Max. 1000
Min. 450 Max. 550
High (14%) Moderate (68%) Low (18%)
Min. 800 Max. 1600–2000
Min. 300 Max. 600
High (10%) Moderate (24%) Low (66%)
Kysuca (375–1236)
988.9
Paleogene of the outer Carpathians (92%)
Loamy soils (65%); Sandy loams (25%); Clay loams (8%)
RA (94%) CM (3%) PZ (2%)
0–7 (18%) 7.1–18 (59%)
Very great (3%); Great (30%); Lowered (65%)
Laborec (150–910)
731.8
Creataceous and Paleogene of the outer Carpathians (99%)
Loamy soils (62%); Sandy loams (23%); Clay loams (15%)
CM (93%) FL (5%)
0–7 (30%) 7.1–18 (58%) 18.1–30 (12%)
Very great (57%); Great (40%); Lowered (3%)
Torysa (230–1289)
1031.9
Loamy soils (45%); Sandy loams (32%); Clay loams (16%)
CM (70%) PG (10%) FL (6%)
0–7 (37%) 7.1–18 (45%) 18.1–30 (15%)
Very great (39%); Great (46%); Lowered (14%)
Topl’a (175–1157)
824.6
Upper Cretaceous and Paleogene of the outer Carpathians (55%); Cretaceous, Paleogene of the outer Carpathians (22%) Creataceous and Paleogene of the outer Carpathians (100%)
Loamy soils (33%); Sandy loams (56%); Loamy sands (9%)
CM (94%) PG (3%) FL (3%)
0–7 (37%) 7.1–18 (50%)
Very great (49%); Great (47%); Lowered
Hron (390–2043)
1408.5
Paleozoic era of veporicum, tatricum (39%); Mesozoic era of the inner Carpathians (25%); igneous rocks (22%)
Loamy sands (43%); Sandy loams (36%); Loams (20%)
RA (11%) CM (57%) PZ (25%)
0–7 (19%) 7.1–18 (39%) >18 (35%)
Very great (10%); Great (28%); Lowered (50%)
Srb, river basin surface; Ss, soil texture (structure); St, soil type; Si, slope inclination; ESL, ecological stability level; P, average annual precipitation level; E, average annual potential evapotranspiration level; T, bedrock transmissivity. Soil types abbreviations: RA, Rendzic Leptosols; CM, Cambisols; PZ, Podzols; FL, Fluvisols; PG, Planosols and Stagnosols.
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River basin (m a.s.l.)
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Table 2 Categories of landscape’s hydric potential. Category
LHP
LHP grade
Characteristics
1
Exceptional
20.0 and more
2
High/very good
10.0–19.9
3
Good/average
0.1–9.9
4 5
Limited Considerably limited
The most significant areas of an exceptional potential of infiltration and precipitation retention The areas of an excellent/very good potential of infiltration and precipitation retention The areas of average potential of infiltration and precipitation retention The areas of limited potential infiltration and precipitation retention The areas of least importance in relation to infiltration and precipitation retention
10.0–0.0 10.1 and less
Kysuca and upper Hron river basins (Fig. 2). Their relatively large area was partially the result of forests with high ecological stability levels. The high LHP values also were influenced by the fact that, in comparison to a larger part of non-forested areas, forested areas showed a higher amount of precipitation and were situated on soils with higher skeletal levels (higher capability of infiltration – Brown, 2003). On the other side, the most significant areas of LHP in agricultural areas were situated on permanent grasslands (PGL) which were hydrologically more suitable than any other non-forested type of land cover (Zachar, 1982; Gordon et al., 2008). In the PGLs of these three catchments, hydrologically adequate soil conditions (mostly the soil type) were prevalent and had more convenient slope inclination conditions (lower relief energy – Midriak, 2008) than forested landscapes. Compared to the forest landscape, the most significant ‘‘disadvantage’’ of most PGLs (except for the natural meadows situated above the upper forest line, or more precisely the PGLs in montane regions) was a lower amount of precipitation (Dale, 1996). The areas categorized into the first two LHP categories, within the river basin of upper Va´h, were closely correlated with declared protected water management areas (PWMA) – the PWMA of the Low Tatras (the eastern and western parts) and the PWMA of the Great Fatra (Fig. 2). The largest areas with favourable conditions for precipitation infiltration and retention were localized in the Western Tatras, their foothills and in the eastern part of the Chocˇ Hills, which correspond with the proposed, identically named PWMA. The high LHP weight of the Kysuca River basin (Table 3), and the significance of its natural conditions in relation to the natural accumulation of water, highlights the fact that the whole river basin makes up a part of the Beskydy and Javornı´ky PWMA. The most important areas were equally
distributed along the Kysuca River, except for its lower watercourse near Kysucke´ Nove´ Mesto and the surroundˇ adca. The proportionally largest areas of the first ings of C LHP category were situated above the Nova´ Bystrica drinking water reservoir and within the catchment of the Klubinsky´ water supply stream. Along with the fluvial sediments of the larger watercourses, these areas were the most significant from the standpoint of precipitation infiltration within the whole Kysuca River basin (Hanzel, 2003). The common denominators in those areas were ecologically stable forests, high annual precipitation amounts (1200 mm) together with lower potential evapotranspiration amounts (350 mm) and tectonically disturbed flysch bedrock (Hanzel, 2003). Another modelled river basin, declared for a broader regional protection of water resources, was the upper Hron River basin. The PWMA of the Low Tatras (the eastern part and the western part to a lesser extent) and the PWMA of the Mura´nska Plateau partially extended into this territory. Their most important LHP sites were situated at higher elevations. From the standpoint of natural infiltration and precipitation retention, valuable areas included the water ˇ ierny Hron, C ˇ ierny potok, supply stream basins of the C Kamenisty´ potok, Osrblianka, Kra´l’ovohol’ske´ Tatry and Fabova hol’a regions. The last of more significant modelled locations was the Topl’a River basin. The whole area of the Topl’a River basin forms a waterworks flow basin. However, the first two categories of the landscape’s hydric potential covered less than 50% of the modelled river basin area. Their larger and connected wholes (Fig. 3) were situated in the upper river basin parts of the Topl’a water supply stream and the watercourses of the Slatvinec, Kamenec, Bardejovsky´ potok and Zbojnı´cky potok, which were also important in the terms of water management. Other significant
Table 3 The percentage of LHP categories and forest coverage of modelled river basins of the Slovak republic. River basin
The upper Va´h Kysuca Laborec Torysa Topl’a The upper Hron
Srb (km2)
2272.5 988.9 731.8 1031.9 824.6 1408.5
LHP category (%)
fc (%)
1
2
3
4
5
5.25 1.45 0.09 0.42 0.3 0.87
55.36 72.29 28.63 27.99 46.2 58.63
35.62 23.92 67.14 62.1 51.2 36.79
3.77 2.34 4.11 9.49 2.3 3.68
0.003 <0.01 0.03 0.01 0.02 0.03
Srb, river basin area; fc, forest coverage of the river basin.
60 57 66 46 41 61
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Fig. 2. Hydric potential of the Va´h, the Kysuca, the Hron river basins and the illustration of selected categories of legislative protection of water resources.
Fig. 3. Hydric potential of Topl’a, Laborec, Torysa river basins and illustration of selected categories of legislative protection of water resources.
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locations were distributed within the larger surroundings of the Bardejov Spa and were protected as regions of natural healing resources. Among the regions classified into the first and second LHP categories, the modelled river basins of the Laborec and the Torysa were the ones with the smallest land area. In both river basins, they represented approximately 28% of the area, mostly associated with the regions situated in ˇ ergov, the Levocˇa Hills and the Laborec the mountains of C Highlands. Within the Torysa modelled river basin, more significant locations were situated in the region of the ˇ mountain range and the springs of the Torysa Bachuren River, the favourable conditions of which have brought about the idea of building the Tichy´ potok drinking water reservoir (Ne´methy, 2003). The smaller occurrence of land areas in the first and second LHP categories within the river basins of the Laborec, the Topl’a and the Torysa was partially caused by the fact that they are not so rich in precipitation and the amounts of potential evapotranspiration were higher. Compared to the modelled river basins of the Va´h, Hron and Kysuca, they mostly had lower percentages of forest coverage (except the Laborec River basin). The lower LHP was also caused by the fact that the river basins are situated on the flysch bedrock, which, compared to the Kysuca River basin, was not so intensely disrupted by tectonic processes (Malı´k et al., 2002; Hanzel, 2003). The soils with the higher amounts of small-grained ˇ urlı´k fractions were created on this geologic substrate (C and Sˇa´ly, 2002), which, despite slower infiltration, were more suitable from the precipitation retention point of view (Zachar, 1982). The graphical representation of LHP spatial variability (Figs. 2 and 3) shows the problem when authenticating the
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definite dependency of their occurrence on a particular landscape attribute. The approach applied in the process of LHP identification was based on the combination of individual physical geographic landscape components and resulted in homogenous areas of hydric potential. The spatial LHP distribution was the sum of the amounts of precipitation and evapotranspiration, slope inclination, soil characteristics, hydrogeological conditions and land cover features which influenced the landscape potential to infiltrate and retain precipitation in a decisive way. The influence of the landscape on infiltration and retention of water must be perceived as a complex outcome of all the relevant river basin characteristics. The work of Solı´n (2008) analyzing the flood situation (third flood activity degree alert) in Slovakia between 1996 and 2006 (Fig. 4) indirectly indicated this fact as well. He interpreted the increase in flood situations within the river basin areas of the Kysuca, Dunajec, Poprad, Torysa, Topl’a and Horna´d rivers by the presence of less permeable Paleogene flysch where soils of low permeability developed predominantly. Still, it did not clarify the low frequency of flood situations in other flysch river basins where neighbouring river basins demonstrated varying incidences of flooding. From the hydrogeologic point of view, compared to the Kysuca, the river basins of the Biele Karpaty mountain watercourses and the Orava River were typical for their less appropriate geologic substrates (Kra´sny´, 1993; Malı´k et al., 2002). However, fewer floods were recorded in the time span between 1996 and 2006 within these areas. Similar phenomena occurred in the neighbouring river basins of the Topl’a, Ondava, Laborec and Cirocha, where, despite considerably better hydrogeologic conditions (Bear, 1988; Kra´sny´, 1993) and soil
Fig. 4. Spatial distribution of municipalities with occurrence of floods from 1996 to 2006 within the modelled river basins (modified according to Solı´n, 2008).
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ˇ urlı´k and Sˇa´ly, 2002), more flood textures (Zachar, 1982; C situations were reported than in the first two cases. Identically to the case of flood occurrence on the flysch substrates, we observed a great deal of variability for this geological substrate in the size and in the spatial organization of localities in the first and second LHP categories (in the modelled river basins of the Kysuca, Topl’a, Torysa and Laborec). Analyzing the physical catchment attributes, Haberlandt et al. (2001) stated that the average base flow index (BFI) was strongly related to topographical, pedological, hydrogeological and precipitation characteristics. On the mesoscale subbasin level the BFI was less influenced by land cover characteristics. The role of land cover characteristics (particularly forests) was presumably higher in the upstream parts of the river basin (Liniger and Weingartner, 1998). The different levels of LHP influence the nature of river basin management. This variation always depends on the local conditions in the river basins, which can be constant (slope inclination, soil texture, the shape of river basins, etc.) or change over time and place (river basin saturation with previous precipitation, frozen soil, the manner and intensity of land use, etc.). According to the outcomes, we were able to determine those regions where water is suitable to be retained or diverted safely. The current conditions of the ecosystems were crucial to be preserved in the regions of high hydric potential. The efforts of decision-making authorities should lead to extensive management. Within the agricultural landscape, these efforts should focus on the transformation of arable soils to permanent grasslands, the exclusion of land fertilization and the protection of the most significant territories by legislative regulations. Generally it is suggested that crop rotations be re-evaluated, crops be planted that are able to enrich the soil with organic matter (Charman and Murphy, 1998) and soil-protective techniques be used (Montgomery, 2007). The principles of multifunctional agriculture should be on the front burner (Guyomard and Le Bris, 2004). Within the forested landscape, it is convenient to reclassify the forest management categories, currently based on a production function, into the forest stands with a primary water management function. As for steep slopes, the classification could also include anti-avalanche or antierosive functions (Lepesˇka, 2010a). There is a need to give a special emphasis to increasing the heterogeneity of forest stands. Wind throws (bark beetle calamities, etc.) represent natural processes of forest ecosystem disturbance (Holling, 1992). This results in far greater age, composition and species diversity and differentiation than that which contributes to ecological stability in forested ecosystems (Franklin et al., 1997). Secondarily and also positive is the presence of dead wood what has positive effects on runoff retardation and infiltration (Bilby and Bisson, 1998), water storage (Harmon et al., 2004) and soil protection (Brown et al., 2007). Within the less important regions, the increase in the landscape’s capability to infiltrate and retain precipitation also is required. The areas endangered by landslides are an exception. In such areas, it would be convenient to extend the forest stands by planting with woods (mainly shrubs) of high root absorption potential. In the areas endangered
by landslides, it is necessary not to extend the forest road network, but to eliminate any interference with the slope integrity, to prefer the natural regeneration of site-suitable trees, to exclude conventional forest management practices and to reclassify them as forests with primary soilprotective functions. Less valuable parcels situated in the inundation zones can be included into the programmes of anti-flood protection with the possibility of decreasing flood flows. The focus of watercourse management measures will probably be concerned with the areas of the third to fifth LHP categories in river basins leading to an increase in the landscape capability to infiltrate and retain precipitation. These measures should primarily lead to an increase in the landscape’s hydric potential. This can be accomplished by the optimal structuring of the landscape, appropriate management of its natural resources, rational management of current and planned socio-economic activities within river basins, and revitalization and renaturalization of the landscape. In areas where landscape hydric functions are insufficient or unavailable, these functions should be increased to an adequate extent by the abovementioned measures. Water retention must be realized by decreasing outflows from concentrated waters in the river basins. This can be achieved by retention in the watercourses and river beds, in water meadow ecosystems (Zhao and He, 2001), in water reservoirs and in a system of ponds (Sˇa´lek et al., 2002). Mitsch and Gosselink (2000) indicated that 0.4 ha of wetland can retain more than 6000 m3 of water. Outflow retention within natural terrain depressions, water reservoirs and systems of ponds, etc., seems to be crucial, mainly during the periods of heavy precipitation and runoff in winter and spring when the soils are frozen and unable to infiltrate and retain the water to the full extent necessary, as well as during extreme precipitation events when the amounts of rainfall cannot be infiltrated into the soil. There are several options to reduce surface run-off in urban ecosystems which are known for their low or no potential to infiltrate and retain precipitation. Permeable vegetation stretches, water meadows or the system of artificial reservoirs can help to retain water (Hvitved-Jacobsen et al., 2010), yet the decrease in the size of non-permeable municipal areas seems to be the most important (Schueller, 1987). 4. Conclusions The LHP is strongly related to precipitation, hydrogeological, pedological, topographical and land cover characteristics of a river basin. Using the relevant characteristics as exploratory variables it was possible to regionalize the LHP for a large heterogeneous river basin. The corrective measures leading to LHP enhancement must recognize the character of the complex interferences as well as the mutually interconnected and coordinated procedures leading to a hydric potential increase in all its significant components. They must be based on scientific and research outcomes and be supported by local authorities, land owners or land fund managers. To fully understand the river basin influence on the watercourse infiltration and retention, further research aimed at the
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quantitative modelling of those landscape attributes influencing the LHP is essential. Conflict of interest statement Author declares there is no conflict of interest. Financial disclosure statement This research was supported by the following projects: APVV-0591-07, APVV-0625-11, VEGA no. 1/1190/12 and UGA I-11-005-09. References Bear, J., 1988. Dynamics of Fluids in Porous Media. Dover Publications. Bilby, R.E., Bisson, P.A., 1998. Function and distribution of large woody debris. River Ecology and Management 13, 324–346. Brown, R.B., 2003. Soil Texture. U.S. Department of Agriculture, Institute of Food and Agricultural Sciences, University of Florida, USA. Brown, R.N., Ek, A.R., Kilgore, M.A., 2007. An Assessment of Dead Wood Standards and Practices in Minnesota. Department of Forest Resources, University of Minnesota, USA. Chang, M., 2003. Forest Hydrology – An Introduction to Water and Forests. CRC Press, Boca Raton, FL, USA. Charman, P.E.V., Murphy, B.W., 1998. Soils: Their Properties and Management. Oxford University Press, USA. ˇ urlı´k, J., Sˇa´ly, R., 2002. Zrnitost’ poˆdy [Soil texture]. In: Miklo´s, L., C Hrncˇiarova´, T. (Eds.), Atlas krajiny SR. MZˇP SR, Bratislava, SAZˇP, Banska´ Bystrica, pp. 110–111. Dale, V.H., 1996. The relationship between land-use change and climate change. Ecological Applications 7, 753–769. Directive 2000/60/EC of the European Parliament of the Council, 2000. Falkenmark, M., Rockstro¨m, J., 2006. The new blue and green water paradigm: breaking new ground for water resources planning and management. Journal of Water Resources Planning and Management 132 (3) 129–132. Franklin, J.F., Berg, D.R., Thornburgh, D.A., Tappeiner, J.C., 1997. Alternative silvicultural approaches to timber harvesting: variable retention harvest systems. In: Kohm, K.A., Franklin, J.F. (Eds.), Proceedings of the Creating a Forestry for the 21st Century. The Science of Ecosystem Management, Washington, DC, pp. 111–139. GeoModel, 1999. Digita´lny model relie´fu DMR50-SK [Digital Elevation Model]. GeoModel, Bratislava, CD. Gordon, L.J., Peterson, G.D., Bennet, E.M., 2008. Agricultural modifications of hydrological flows create ecological surprises. Trends in Ecology and Evolution 23 (4) 211–219. Guyomard, H., Le Bris, K., 2004. Multilateral Agricultural Negotiations and Multifunctionality: Some Research Issues. ENARPRI Thematic Network on Trade Agreements and European Agriculture, Policy Brief, Brussels (4). Haberlandt, U., Klo¨cking, B., Krysanova, V., Becker, A., 2001. Regionalisation of the base flow index from dynamically simulated flow components – a case study in the Elbe River basin. Journal of Hydrology 248, 35–53. Hanzel, V., 2003. Hydrogeolo´gia regio´nu Kysu´c [Hydrogeology of the Kysuce Region]. Podzemna´ voda 9 (2) 46–65 (English abstract). Harmon, M.E., Franklin, J.F., Swanson, F.J., Sollins, P., Gregory, S.V., Lattin, J.D., Anderson, N.H., Cline, S.P., Aumen, N.G., Sedell, J.R., Lienkaemper, G.W., Cromack, K., Cummins, K.W., 2004. Ecology of coarse woody debris in temperate ecosystems. Advances in Ecological Research 34, 59–234. Holko, L., 2010. Voda v krajine a povodne [Water in landscape and floods]. Urbanita 22 (4) 20–24. Holling, C.S., 1992. Cross-scale morphology, geometry, and dynamics of ecosystems. Ecological Monographs 62 (4) 447–502. Hvitved-Jacobsen, T., Vollersten, J., Nielsen, A.H., 2010. Urban and Highway Stormwater Pollution. Taylor Francis Group, Boca Raton, USA.
209
Kra´sny´, J., 1993. Classification of transmissivity magnitude and variation. Ground Water 31 (2) 230–236. Leeper, G.W., Uren, N.C., 1993. Soil Science: An Introduction, 5th ed. University Press, Melbourne, Australia. Lepesˇka, T., 2010a. Integrovany´ manazˇment povodı´ v horsky´ch a podhorsky´ch oblastiach [Integrated River Basin Managent in Mountain and Submontane Regions]. Technical University in Zvolen, Slovakia. Lepesˇka, T., 2010b. Hydric potential of landscape and integrated river basin management in mountain and submontane regions. Ecohydrology & Hydrobiology 10 (1) 13–24. Liniger, H., Weingartner, R., 1998. Mountains and freshwater supply. Unasylva 49, 39–46. Malı´k, P., Sˇvasta, J., Jetel, J., Hanzel, V., Gedeon, M., Scherer, S., Fendek, M., 2002. Hydrogeologicke´ pomery [Hydrogeology]. In: Miklo´s, L., Hrncˇiarova´, T. (Eds.), Atlas krajiny SR. MZˇP SR, Bratislava, SAZˇP, Banska´ Bystrica, p. 102. Marsalek, J., Jimenez-Cisneros, B.E., Malmquist, P.A., Karamouz, M., Goldenfum, J., Chocat, B., 2006. Urban Water Cycle Processes and Interactions. International Hydrological Programme – V, Technical Documents in Hydrology, vol. 78. UNESCO, Paris. Maser, C., Trappe, J.M., 1984. The Seen and Unseen World of the Fallen Tree. Department of Agriculture, Forest Service, Portland, USA. Midriak, R., 2008. Present-day retreat of slopes above the upper timberline in the Slovak part of the Western Carpathians. Geographia Polonica 9, 93–100. Miklo´s, L., Hrncˇiarova´, T. (Eds.), 2002. Atlas krajiny Slovenskej republiky [Landscape Atlas of the Slovak Republic]. MZˇP SR Bratislava, SAZˇP, Banska´ Bystrica, Slovakia. Mitsch, W.J., Gosselink, J.G., 2000. Wetlands, 3rd ed. John Wiley & Sons Inc., New York, USA. Montgomery, D.R., 2007. Soil erosion and agricultural sustainability. Proceedings of the National Academy of Sciences 104 (33) 13268– 13272. Ne´methy, P., 2003. Hydrogeologicke´ pomery okolia projektovanej voda´renskej na´drzˇe Tichy´ potok [Hydrogeological settings of surroundings of projected drinking water reservoir Tichy´ Potok]. Podzemna´ voda 9 (1) 52–59 (English abstract). Peck, A.J., Wiliamson, D.R., 1987. Effects of forest clearing on groundwater. Journal of Hydrology 94, 47–65. Schueller, T.R., 1987. Controlling Urban Runoff: A Practical Manual for Planning and Designing Urban BMPs. Publication No. 87703. Metropolitan Washington Council of Governments, USA. Slovak Environmental Agency, 2004. GIS CORINE Landcover 2000 Shapefile. SAZˇP, Banska´ Bystrica. ˇ ovy´ch sita´ciı´ na Slovensku v Solı´n, L’., 2008. Analy´za vy´skytu povodn obdobı´ rokov 1996–2006 [Analysis of floods occurrence in Slovakia]. Journal of Hydrology and Hydromechanics 56 (2) 95–115. ˇ ovej hrozby maly´ch povodı´ Solı´n, L’., 2011. Regiona´lna variabilita povodn na Slovensku [Regional variability of flood threat in small basins of Slovakia]. Geographical Journal 63, 29–52. Sˇa´lek, J., Mala´, E., Sˇtencel, M., 2002. Netradicˇnı´ zpu˚soby rˇesˇenı´ vodnı´ho hospoda´rˇstvı´ krajiny [Unconventional solutions of landscape’s water management]. In: Kozova´, M., Pavlicˇkova´, K., Barka, I. (Eds.), Nove´ trendy v krajinnej ekolo´gii [New trends in Landscape Ecology]. Comenius University, Bratislava, (English abstract), pp. 363–372. ´ PU ´ Sˇa´ly, R., Midriak, R., 1995. Water erosion in Slovakia. Vedecke´ pra´ce VU 19 (1) 169–175. Zachar, D., 1982. Soil Erosion. Developments in Soil Science, Vol. 10. Elsevier. Zalewski, M., 2000. Ecohydrology – the scientific background to use ecosystem properties as management tools toward sustainability of water resources. Ecological Engineering 16, 1–8. Zalewski, M., Wagner, I., 2005. Ecohydrology – the use of water and ecosystem processes for healthy urban environments. Ecohydrology & Hydrobiology 5 (4) 263–268. Zalewski, M., Janauer, G., Jola´nkai, G. (Eds.), 1997. Ecohydrology. A New Paradigm for the Sustainable Use of Aquatic Resources. UNESCO, Paris. Zhao, K., He, C., 2001. Wetland types, functions and conservation in China. Chinese Geographical Science 11 (4), 300–305.
Contents lists available at ScienceDirect
Ecohydrology & Hydrobiology journal homepage: www.elsevier.com/locate/ecohyd
Original research article
Hydric potential of selected river basins in Slovakia Toma´sˇ Lepesˇka a,b,* a
Department of Applied Ecology, Faculty of Ecology and Environmental Sciences, Technical University in Zvolen, T. G. Masaryka 2117/24, 960 53 Zvolen, Slovakia b Institute of Landscape and Regions Research, Department of Science and Research, Matej Bel University in Banska´ Bystrica, Cesta na amfitea´ter 1, 947 01 Banska´ Bystrica, Slovakia
A R T I C L E I N F O
A B S T R A C T
Article history: Received 6 March 2013 Accepted 22 August 2013 Available online 5 September 2013
Landscape attributes affect the quantity, quality, distribution and accessibility of water resources. Except for fixed and hardly impacted environmental characteristics affecting the hydric potential of the landscape, it is possible by optimal land use planning and management to modify its ability to infiltrate and detain precipitation. The use of landscape characteristics as an efficient tool in river basin management can improve disturbed conditions in catchments. In this paper, we have focused on the evaluation of the hydric potential of six river basins in Slovakia. Assessing the most relevant landscape attributes in relation to the protection of water resources, we have identified areas with various landscape hydric potentials (LHPs), which should be taken into consideration when developing a river basin management plan. The spatial distribution of LHP categories undermines the customary view that the landscape’s ability to infiltrate and retain water is affected by only some of the physical–geographic attributes (frequently presented as hydrogeological bedrock and soil characteristics). The LHP distribution in model catchments is explained through specific combinations of factors having the greatest influence. ß 2013 European Regional Centre for Ecohydrology of Polish Academy of Sciences. Published by Elsevier Urban & Partner Sp. z o.o. All rights reserved.
Keywords: Hydric potential Landscape Integrated river basin management Water resources Slovakia
1. Introduction Water as an integrating element interconnects other elements and components of the environment. The number of water resources, their quality, accessibility and distribution, as well as their ecosystem processes, is bound to climatic, abiotic and biotic factors that predetermine their management based on a holistic approach. The holistic approach presenting the idea that ‘‘the whole is more than its individual parts’’ establishes integrated river basin management as the basis of contemporary perceptions of water sources and the landscape. It points to the fact that water resources cannot be managed individually or through individual landscape attributes,
* Tel.: +421 907 126 842. E-mail address: [email protected].
such as vegetation, soil, etc., but refers to the necessity of a water basin management perspective that considers all the crucial elements of the water – landscape system as a whole. From the perspective of the socio-economic field, it also implies the idea of managing and adopting an equitable approach to water and other natural resources as well as all the other ecosystems within the river basin. 1.1. Ecohydrology principles in landscape’s hydric potential Interactions between precipitation (water) and landscape attributes are variable. Variability is imposed by local conditions within a catchment which can be constant (e.g. slope inclination, soil texture, etc.) or changing (present hydrometeorological conditions, catchment saturation state, land use, soil ice, etc.). For evaluating the landscape or ecosystem effect on the quality, quantity, distribution and accessibility of water resources there is a
1642-3593/$ – see front matter ß 2013 European Regional Centre for Ecohydrology of Polish Academy of Sciences. Published by Elsevier Urban & Partner Sp. z o.o. All rights reserved. http://dx.doi.org/10.1016/j.ecohyd.2013.08.004
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need to determine the physical and geographical attributes that are crucial within the water-landscape complex. Since infiltration, retention and runoff are determined by a complex of factors which can also act contrarily, the effect of a particular landscape attribute can be very specific. The determining physico-geographical factors are bedrock transmissivity (Bear, 1988); an average annual precipitation amount; an average annual amount of evapotranspiration; geomorphologic conditions (Zachar, 1982); soil textures and types (Leeper and Uren, 1993); the composition, structure, stability, originality and health condition of forest stands – that results in their ecological stability (Maser and Trappe, 1984; Chang, 2003); and the characteristics, structure and intensity of land use (Peck and Wiliamson, 1987; Dale, 1996; Gordon et al., 2008). Their mutual interactions, synergistic or antagonistic, determine the resultant effects of the landscape (ecosystems) on water resources. The fact, that ecosystem management can influence hydrologic processes or vice versa – that biological processes can be managed by the hydrological parameters, led to the formulation of the paradigm of landscape management called ecohydrology (Zalewski, 2000). Ecohydrological hypotheses are particularly focused on managing both the quality and the number of water resources by means of increasing the resistance, resilience and inhibiting ability of river ecosystem biota to change, as well as to other biological characteristics of river corridors (Zalewski et al., 1997; Zalewski, 2000). To a certain extent, it lacks the emphasis on integration by considering key elements of the river basin, such as soil, relief characteristics, hydrogeological conditions and the use of the forested and non-forested landscape as well as climatic conditions. On the basis of the ecohydrological hypotheses and through river basin attribute assessment, we can define a landscape’s hydric potential (Lepesˇka, 2010a, 2010b). The landscape’s hydric potential (LHP) refers to the ability of the landscape to decelerate and detain precipitation and the capability of the water to infiltrate into ground. Temporary detention of water on/in vegetation, in the humus layer, soil, and bedrock, and in micro-depressions also can be understood under this term. It is the influence of various elements and components of the landscape on the amount, quality, distribution and accessibility of water resources. Based on the LHP, we can objectively consider the regions where it is possible to keep the current way of using the landscape and those in which it is necessary to design a new approach. It is obvious that good water resources can be achieved by managing ecosystems and human activities in an appropriate way, which is one of the main requirements arising from the Water Framework Directive (Directive 2000/60/EC, 2000). The effort of decision-making authorities should primarily lead to the increase of the landscape’s hydric potential. That can be accomplished by the optimal structuring of the landscape, appropriate management of its natural resources and economical management of current and planned socio-economic activities within river basins. The use of landscape (ecosystem) characteristics as an efficient tool in river basin management can lead to water
retention within landscape (Zalewski and Wagner, 2005), transformation of unwanted surface run-off into subsurface storage (Sˇa´ly and Midriak, 1995), an increase in the quality of water resources (by reduction of nutrient input, denitrification and filtration) (Falkenmark and Rockstro¨m, 2006), protection of water, soil and the food chain from hazardous element contamination and increase the water amount in watercourses. The advantages of optimal water basin management can be far wider. It can increase underground water storage, reduce stream flooding and, in the broadest consequence, raise the quality of life and increase aesthetic values and the health of the population in urban ecosystems (Zalewski and Wagner, 2005). Marsalek et al. (2006) have recently shown that the implementation of an ecohydrology approach can eliminate flood hazards in the urban landscape. The LHP is a result of the interaction of all relevant river basin attributes. Some authors give a special emphasis to particular physical and geographical components like bedrock transmissivity, soil texture (Holko, 2010; Solı´n, 2011) or forest cover (Liniger and Weingartner, 1998) when evaluating infiltration. The aim of this paper is to identify the LHP of six selected river basins and to determine the different ecosystem attributes that influence the infiltration, deceleration and detention of precipitation. Our purpose is to describe how the LHP changes in heterogeneous river basins when evaluated using the same attributes. By comparing the LHPs, the optimal management strategy for a specific partial river basin can be suggested and its function within the system of the main watercourse or coastal drainage area can be defined. We focused on basins situated in heterogenic natural conditions which consisted of mountain and submontane regions to a large extent. The quality, amount, accessibility and distribution of water resources in the lower elevation regions depend on the usage intensity in the upper parts of the river basins. This interconnection of needs between users of natural resources in both the upper and lower river basins, along with their often contradictory demands on environmental and natural resources, shows the importance of negotiations among all the parties engaged in the hydrological cycle. 2. Materials and methods 2.1. Description of the model river basins The experimental areas were chosen as follows: (1) the upper Va´h River basin (the Va´h River basin down to its confluence with the Orava River at Kral’ovany), (2) the Kysuca River basin, (3) the upper part of the Laborec River basin (the area of the Laborec River basin down to its confluence with the Cirocha River near Humenne´), (4) part of the Topl’a River basin (the Topl’a River basin down to its confluence with the Radomka River near Giraltovce), (5) the upper part of the Torysa River basin (down to Presˇov) and (6) the upper part of the Hron River basin (down to the mouth of the Hutna´ River above the village of Lucˇatı´n). The location of experimental river basins within Slovakia is
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shown in Fig. 1. The river basins were chosen to represent various physical geographic characteristics of mountain and submontane river basins in Slovakia. These river basins are left-hand tributaries of the Danube River. Their areas varied from 732 to 2272 km2 and the catchments are situated within an elevation range of 150–2494 m a.s.l. with an average annual precipitation of 700 mm in the lowest parts and 2000 mm in the upper parts. Predominating bedrock is flysch together with Mesozoic and Palaeozoic rocks on which has developed mostly loamy soils and sandy loams or loamy sands. Forest stands are the prevailing type of land cover varying from 41 to 66% of areal coverage. In describing these areas, we focused on their environmental features which influence the overall landscape’s hydric potential to a significant extent. These features included: transmissivity of bedrock; average annual precipitation levels; average annual potential evapotranspiration levels; slope inclination conditions of the areas; soil types and textures; the composition, structure, condition, stability and originality of the forest stands; and the characteristics, structure and usage intensity of non-forested landscapes. The aggregated physical catchment descriptors for all subbasins are listed in Table 1, which shows a strong heterogeneity including a wide range in the geological, pedological, topographical, land use and climate conditions. 2.2. Methods To identify the landscape’s hydric potential of the chosen river basin areas, we used the methodology according to Lepesˇka (2010b). It is based on the assessment of the average amount of precipitation in a particular river basin and on landscape attributes influencing runoff infiltration, deceleration and retention. Each landscape attribute was assessed according to its quality, or more precisely its exceptionality. The methodology results in LHP grades for each of the modelled river basins.
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Subsequently, the grades were classified into five categories (Table 2) and will be used as the basis for formulating optimal river basin management strategies. The reference materials used to identify the hydric potential of the modelled river basins were as follows: land cover data (CORINE Land Cover) provided by Slovak Environmental Agency (SEA, 2004), data from forest management plans (on the ecological stability level of the forest stands) provided by National Forest Centre in Zvolen, map and cartographic data taken from Landscape Atlas of the Slovak Republic (Miklo´s and Hrncˇiarova´, 2002), data on Slovak digital relief in raster format with 50 m resolution (GeoModel, 1999) and base maps of the Slovak Republic at the scale of 1:10,000. When necessary, the data were refined and updated using field investigations. The analysis, processing, and synthesis of the reference materials, and the evaluation and creation of the maps of hydric potential model river basins were realized using the GIS software of ArcView 3.2 and ArcGis 9.3. 3. Results and discussion 3.1. Landscape’s hydric potential The outcome of landscape’s hydric potential evaluation of the modelled river basins was the establishment of LHP grades and their subsequent categorization into five categories according to their potential to infiltrate and retain precipitation. The areas classified into the first and second categories of LHP were ranked as the most significant. Depending on their size, compactness and distribution within the river basin, the overall significance of the studied areas for water resources management was developed. The percentage of LHP categories in the modelled river basins in the Slovak Republic is shown in Table 3, with their spatial distribution shown in Figs. 2 and 3. The best landscape’s hydric potentials (the localities classified in the first two categories) were in the upper Va´h,
Fig. 1. Distribution of model river basins in Slovakia.
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Table 1 Physical and geographical attributes of the model river basins affecting the spatial variability LHP. Srb (km2)
Bedrock composition
Ss
St
Si (8)
ESL of forest ecosystems
Land cover
P (mm)
E (mm)
T
Va´h (430–2494)
2272.5
Mesozoic era (45%); flysch (28%); igneous rocks (15%)
Loamy soils (45%); Sandy loams (35%); Loamy sands (11%)
RA (30%) CM (30%) PZ (20%)
0–7 (22%) 7.1–18 (27%) 18 (50%)
Very great (10%); Great (46%); Lowered (44%)
Forest stands (60%); Agricultural landscape (30%); Urban and industrial areas (4%) Forest stands (57%); Agricultural landscape (40%); Urban and industrial areas (3%) Forest stands (66%); Agricultural landscape (31%); Urban and industrial areas (3%) Forest stands (46%); Agricultural landscape (47%); Urban and industrial areas (7%)
Min. 700 Max. 2130
Min. 300 Max. 600
High (23%) Moderate (46%) Low (31%)
Min. 800 Max. 1600
Min. 350 Max. 500
High (25%) Moderate (55%) Low (20%)
Min. 700 Max. 1200
Min. 400 Max. 600
High (22%) Moderate (72%) Low (6%)
Min. 550 Max. 1000
Min. 400 Max. 650
High (4%) Moderate (87%) Low (9%)
Forest stands (41%); Agricultural landscape (55%); Urban and industrial areas (4%) Forest stands (61%); Agricultural landscape (21%); Urban and industrial areas (3%)
Min. 700 Max. 1000
Min. 450 Max. 550
High (14%) Moderate (68%) Low (18%)
Min. 800 Max. 1600–2000
Min. 300 Max. 600
High (10%) Moderate (24%) Low (66%)
Kysuca (375–1236)
988.9
Paleogene of the outer Carpathians (92%)
Loamy soils (65%); Sandy loams (25%); Clay loams (8%)
RA (94%) CM (3%) PZ (2%)
0–7 (18%) 7.1–18 (59%)
Very great (3%); Great (30%); Lowered (65%)
Laborec (150–910)
731.8
Creataceous and Paleogene of the outer Carpathians (99%)
Loamy soils (62%); Sandy loams (23%); Clay loams (15%)
CM (93%) FL (5%)
0–7 (30%) 7.1–18 (58%) 18.1–30 (12%)
Very great (57%); Great (40%); Lowered (3%)
Torysa (230–1289)
1031.9
Loamy soils (45%); Sandy loams (32%); Clay loams (16%)
CM (70%) PG (10%) FL (6%)
0–7 (37%) 7.1–18 (45%) 18.1–30 (15%)
Very great (39%); Great (46%); Lowered (14%)
Topl’a (175–1157)
824.6
Upper Cretaceous and Paleogene of the outer Carpathians (55%); Cretaceous, Paleogene of the outer Carpathians (22%) Creataceous and Paleogene of the outer Carpathians (100%)
Loamy soils (33%); Sandy loams (56%); Loamy sands (9%)
CM (94%) PG (3%) FL (3%)
0–7 (37%) 7.1–18 (50%)
Very great (49%); Great (47%); Lowered
Hron (390–2043)
1408.5
Paleozoic era of veporicum, tatricum (39%); Mesozoic era of the inner Carpathians (25%); igneous rocks (22%)
Loamy sands (43%); Sandy loams (36%); Loams (20%)
RA (11%) CM (57%) PZ (25%)
0–7 (19%) 7.1–18 (39%) >18 (35%)
Very great (10%); Great (28%); Lowered (50%)
Srb, river basin surface; Ss, soil texture (structure); St, soil type; Si, slope inclination; ESL, ecological stability level; P, average annual precipitation level; E, average annual potential evapotranspiration level; T, bedrock transmissivity. Soil types abbreviations: RA, Rendzic Leptosols; CM, Cambisols; PZ, Podzols; FL, Fluvisols; PG, Planosols and Stagnosols.
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River basin (m a.s.l.)
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Table 2 Categories of landscape’s hydric potential. Category
LHP
LHP grade
Characteristics
1
Exceptional
20.0 and more
2
High/very good
10.0–19.9
3
Good/average
0.1–9.9
4 5
Limited Considerably limited
The most significant areas of an exceptional potential of infiltration and precipitation retention The areas of an excellent/very good potential of infiltration and precipitation retention The areas of average potential of infiltration and precipitation retention The areas of limited potential infiltration and precipitation retention The areas of least importance in relation to infiltration and precipitation retention
10.0–0.0 10.1 and less
Kysuca and upper Hron river basins (Fig. 2). Their relatively large area was partially the result of forests with high ecological stability levels. The high LHP values also were influenced by the fact that, in comparison to a larger part of non-forested areas, forested areas showed a higher amount of precipitation and were situated on soils with higher skeletal levels (higher capability of infiltration – Brown, 2003). On the other side, the most significant areas of LHP in agricultural areas were situated on permanent grasslands (PGL) which were hydrologically more suitable than any other non-forested type of land cover (Zachar, 1982; Gordon et al., 2008). In the PGLs of these three catchments, hydrologically adequate soil conditions (mostly the soil type) were prevalent and had more convenient slope inclination conditions (lower relief energy – Midriak, 2008) than forested landscapes. Compared to the forest landscape, the most significant ‘‘disadvantage’’ of most PGLs (except for the natural meadows situated above the upper forest line, or more precisely the PGLs in montane regions) was a lower amount of precipitation (Dale, 1996). The areas categorized into the first two LHP categories, within the river basin of upper Va´h, were closely correlated with declared protected water management areas (PWMA) – the PWMA of the Low Tatras (the eastern and western parts) and the PWMA of the Great Fatra (Fig. 2). The largest areas with favourable conditions for precipitation infiltration and retention were localized in the Western Tatras, their foothills and in the eastern part of the Chocˇ Hills, which correspond with the proposed, identically named PWMA. The high LHP weight of the Kysuca River basin (Table 3), and the significance of its natural conditions in relation to the natural accumulation of water, highlights the fact that the whole river basin makes up a part of the Beskydy and Javornı´ky PWMA. The most important areas were equally
distributed along the Kysuca River, except for its lower watercourse near Kysucke´ Nove´ Mesto and the surroundˇ adca. The proportionally largest areas of the first ings of C LHP category were situated above the Nova´ Bystrica drinking water reservoir and within the catchment of the Klubinsky´ water supply stream. Along with the fluvial sediments of the larger watercourses, these areas were the most significant from the standpoint of precipitation infiltration within the whole Kysuca River basin (Hanzel, 2003). The common denominators in those areas were ecologically stable forests, high annual precipitation amounts (1200 mm) together with lower potential evapotranspiration amounts (350 mm) and tectonically disturbed flysch bedrock (Hanzel, 2003). Another modelled river basin, declared for a broader regional protection of water resources, was the upper Hron River basin. The PWMA of the Low Tatras (the eastern part and the western part to a lesser extent) and the PWMA of the Mura´nska Plateau partially extended into this territory. Their most important LHP sites were situated at higher elevations. From the standpoint of natural infiltration and precipitation retention, valuable areas included the water ˇ ierny Hron, C ˇ ierny potok, supply stream basins of the C Kamenisty´ potok, Osrblianka, Kra´l’ovohol’ske´ Tatry and Fabova hol’a regions. The last of more significant modelled locations was the Topl’a River basin. The whole area of the Topl’a River basin forms a waterworks flow basin. However, the first two categories of the landscape’s hydric potential covered less than 50% of the modelled river basin area. Their larger and connected wholes (Fig. 3) were situated in the upper river basin parts of the Topl’a water supply stream and the watercourses of the Slatvinec, Kamenec, Bardejovsky´ potok and Zbojnı´cky potok, which were also important in the terms of water management. Other significant
Table 3 The percentage of LHP categories and forest coverage of modelled river basins of the Slovak republic. River basin
The upper Va´h Kysuca Laborec Torysa Topl’a The upper Hron
Srb (km2)
2272.5 988.9 731.8 1031.9 824.6 1408.5
LHP category (%)
fc (%)
1
2
3
4
5
5.25 1.45 0.09 0.42 0.3 0.87
55.36 72.29 28.63 27.99 46.2 58.63
35.62 23.92 67.14 62.1 51.2 36.79
3.77 2.34 4.11 9.49 2.3 3.68
0.003 <0.01 0.03 0.01 0.02 0.03
Srb, river basin area; fc, forest coverage of the river basin.
60 57 66 46 41 61
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Fig. 2. Hydric potential of the Va´h, the Kysuca, the Hron river basins and the illustration of selected categories of legislative protection of water resources.
Fig. 3. Hydric potential of Topl’a, Laborec, Torysa river basins and illustration of selected categories of legislative protection of water resources.
T. Lepesˇka / Ecohydrology & Hydrobiology 13 (2013) 201–209
locations were distributed within the larger surroundings of the Bardejov Spa and were protected as regions of natural healing resources. Among the regions classified into the first and second LHP categories, the modelled river basins of the Laborec and the Torysa were the ones with the smallest land area. In both river basins, they represented approximately 28% of the area, mostly associated with the regions situated in ˇ ergov, the Levocˇa Hills and the Laborec the mountains of C Highlands. Within the Torysa modelled river basin, more significant locations were situated in the region of the ˇ mountain range and the springs of the Torysa Bachuren River, the favourable conditions of which have brought about the idea of building the Tichy´ potok drinking water reservoir (Ne´methy, 2003). The smaller occurrence of land areas in the first and second LHP categories within the river basins of the Laborec, the Topl’a and the Torysa was partially caused by the fact that they are not so rich in precipitation and the amounts of potential evapotranspiration were higher. Compared to the modelled river basins of the Va´h, Hron and Kysuca, they mostly had lower percentages of forest coverage (except the Laborec River basin). The lower LHP was also caused by the fact that the river basins are situated on the flysch bedrock, which, compared to the Kysuca River basin, was not so intensely disrupted by tectonic processes (Malı´k et al., 2002; Hanzel, 2003). The soils with the higher amounts of small-grained ˇ urlı´k fractions were created on this geologic substrate (C and Sˇa´ly, 2002), which, despite slower infiltration, were more suitable from the precipitation retention point of view (Zachar, 1982). The graphical representation of LHP spatial variability (Figs. 2 and 3) shows the problem when authenticating the
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definite dependency of their occurrence on a particular landscape attribute. The approach applied in the process of LHP identification was based on the combination of individual physical geographic landscape components and resulted in homogenous areas of hydric potential. The spatial LHP distribution was the sum of the amounts of precipitation and evapotranspiration, slope inclination, soil characteristics, hydrogeological conditions and land cover features which influenced the landscape potential to infiltrate and retain precipitation in a decisive way. The influence of the landscape on infiltration and retention of water must be perceived as a complex outcome of all the relevant river basin characteristics. The work of Solı´n (2008) analyzing the flood situation (third flood activity degree alert) in Slovakia between 1996 and 2006 (Fig. 4) indirectly indicated this fact as well. He interpreted the increase in flood situations within the river basin areas of the Kysuca, Dunajec, Poprad, Torysa, Topl’a and Horna´d rivers by the presence of less permeable Paleogene flysch where soils of low permeability developed predominantly. Still, it did not clarify the low frequency of flood situations in other flysch river basins where neighbouring river basins demonstrated varying incidences of flooding. From the hydrogeologic point of view, compared to the Kysuca, the river basins of the Biele Karpaty mountain watercourses and the Orava River were typical for their less appropriate geologic substrates (Kra´sny´, 1993; Malı´k et al., 2002). However, fewer floods were recorded in the time span between 1996 and 2006 within these areas. Similar phenomena occurred in the neighbouring river basins of the Topl’a, Ondava, Laborec and Cirocha, where, despite considerably better hydrogeologic conditions (Bear, 1988; Kra´sny´, 1993) and soil
Fig. 4. Spatial distribution of municipalities with occurrence of floods from 1996 to 2006 within the modelled river basins (modified according to Solı´n, 2008).
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ˇ urlı´k and Sˇa´ly, 2002), more flood textures (Zachar, 1982; C situations were reported than in the first two cases. Identically to the case of flood occurrence on the flysch substrates, we observed a great deal of variability for this geological substrate in the size and in the spatial organization of localities in the first and second LHP categories (in the modelled river basins of the Kysuca, Topl’a, Torysa and Laborec). Analyzing the physical catchment attributes, Haberlandt et al. (2001) stated that the average base flow index (BFI) was strongly related to topographical, pedological, hydrogeological and precipitation characteristics. On the mesoscale subbasin level the BFI was less influenced by land cover characteristics. The role of land cover characteristics (particularly forests) was presumably higher in the upstream parts of the river basin (Liniger and Weingartner, 1998). The different levels of LHP influence the nature of river basin management. This variation always depends on the local conditions in the river basins, which can be constant (slope inclination, soil texture, the shape of river basins, etc.) or change over time and place (river basin saturation with previous precipitation, frozen soil, the manner and intensity of land use, etc.). According to the outcomes, we were able to determine those regions where water is suitable to be retained or diverted safely. The current conditions of the ecosystems were crucial to be preserved in the regions of high hydric potential. The efforts of decision-making authorities should lead to extensive management. Within the agricultural landscape, these efforts should focus on the transformation of arable soils to permanent grasslands, the exclusion of land fertilization and the protection of the most significant territories by legislative regulations. Generally it is suggested that crop rotations be re-evaluated, crops be planted that are able to enrich the soil with organic matter (Charman and Murphy, 1998) and soil-protective techniques be used (Montgomery, 2007). The principles of multifunctional agriculture should be on the front burner (Guyomard and Le Bris, 2004). Within the forested landscape, it is convenient to reclassify the forest management categories, currently based on a production function, into the forest stands with a primary water management function. As for steep slopes, the classification could also include anti-avalanche or antierosive functions (Lepesˇka, 2010a). There is a need to give a special emphasis to increasing the heterogeneity of forest stands. Wind throws (bark beetle calamities, etc.) represent natural processes of forest ecosystem disturbance (Holling, 1992). This results in far greater age, composition and species diversity and differentiation than that which contributes to ecological stability in forested ecosystems (Franklin et al., 1997). Secondarily and also positive is the presence of dead wood what has positive effects on runoff retardation and infiltration (Bilby and Bisson, 1998), water storage (Harmon et al., 2004) and soil protection (Brown et al., 2007). Within the less important regions, the increase in the landscape’s capability to infiltrate and retain precipitation also is required. The areas endangered by landslides are an exception. In such areas, it would be convenient to extend the forest stands by planting with woods (mainly shrubs) of high root absorption potential. In the areas endangered
by landslides, it is necessary not to extend the forest road network, but to eliminate any interference with the slope integrity, to prefer the natural regeneration of site-suitable trees, to exclude conventional forest management practices and to reclassify them as forests with primary soilprotective functions. Less valuable parcels situated in the inundation zones can be included into the programmes of anti-flood protection with the possibility of decreasing flood flows. The focus of watercourse management measures will probably be concerned with the areas of the third to fifth LHP categories in river basins leading to an increase in the landscape capability to infiltrate and retain precipitation. These measures should primarily lead to an increase in the landscape’s hydric potential. This can be accomplished by the optimal structuring of the landscape, appropriate management of its natural resources, rational management of current and planned socio-economic activities within river basins, and revitalization and renaturalization of the landscape. In areas where landscape hydric functions are insufficient or unavailable, these functions should be increased to an adequate extent by the abovementioned measures. Water retention must be realized by decreasing outflows from concentrated waters in the river basins. This can be achieved by retention in the watercourses and river beds, in water meadow ecosystems (Zhao and He, 2001), in water reservoirs and in a system of ponds (Sˇa´lek et al., 2002). Mitsch and Gosselink (2000) indicated that 0.4 ha of wetland can retain more than 6000 m3 of water. Outflow retention within natural terrain depressions, water reservoirs and systems of ponds, etc., seems to be crucial, mainly during the periods of heavy precipitation and runoff in winter and spring when the soils are frozen and unable to infiltrate and retain the water to the full extent necessary, as well as during extreme precipitation events when the amounts of rainfall cannot be infiltrated into the soil. There are several options to reduce surface run-off in urban ecosystems which are known for their low or no potential to infiltrate and retain precipitation. Permeable vegetation stretches, water meadows or the system of artificial reservoirs can help to retain water (Hvitved-Jacobsen et al., 2010), yet the decrease in the size of non-permeable municipal areas seems to be the most important (Schueller, 1987). 4. Conclusions The LHP is strongly related to precipitation, hydrogeological, pedological, topographical and land cover characteristics of a river basin. Using the relevant characteristics as exploratory variables it was possible to regionalize the LHP for a large heterogeneous river basin. The corrective measures leading to LHP enhancement must recognize the character of the complex interferences as well as the mutually interconnected and coordinated procedures leading to a hydric potential increase in all its significant components. They must be based on scientific and research outcomes and be supported by local authorities, land owners or land fund managers. To fully understand the river basin influence on the watercourse infiltration and retention, further research aimed at the
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quantitative modelling of those landscape attributes influencing the LHP is essential. Conflict of interest statement Author declares there is no conflict of interest. Financial disclosure statement This research was supported by the following projects: APVV-0591-07, APVV-0625-11, VEGA no. 1/1190/12 and UGA I-11-005-09. References Bear, J., 1988. Dynamics of Fluids in Porous Media. Dover Publications. Bilby, R.E., Bisson, P.A., 1998. Function and distribution of large woody debris. River Ecology and Management 13, 324–346. Brown, R.B., 2003. Soil Texture. U.S. Department of Agriculture, Institute of Food and Agricultural Sciences, University of Florida, USA. Brown, R.N., Ek, A.R., Kilgore, M.A., 2007. An Assessment of Dead Wood Standards and Practices in Minnesota. Department of Forest Resources, University of Minnesota, USA. Chang, M., 2003. Forest Hydrology – An Introduction to Water and Forests. CRC Press, Boca Raton, FL, USA. Charman, P.E.V., Murphy, B.W., 1998. Soils: Their Properties and Management. Oxford University Press, USA. ˇ urlı´k, J., Sˇa´ly, R., 2002. Zrnitost’ poˆdy [Soil texture]. In: Miklo´s, L., C Hrncˇiarova´, T. (Eds.), Atlas krajiny SR. MZˇP SR, Bratislava, SAZˇP, Banska´ Bystrica, pp. 110–111. Dale, V.H., 1996. The relationship between land-use change and climate change. Ecological Applications 7, 753–769. Directive 2000/60/EC of the European Parliament of the Council, 2000. Falkenmark, M., Rockstro¨m, J., 2006. The new blue and green water paradigm: breaking new ground for water resources planning and management. Journal of Water Resources Planning and Management 132 (3) 129–132. Franklin, J.F., Berg, D.R., Thornburgh, D.A., Tappeiner, J.C., 1997. Alternative silvicultural approaches to timber harvesting: variable retention harvest systems. In: Kohm, K.A., Franklin, J.F. (Eds.), Proceedings of the Creating a Forestry for the 21st Century. The Science of Ecosystem Management, Washington, DC, pp. 111–139. GeoModel, 1999. Digita´lny model relie´fu DMR50-SK [Digital Elevation Model]. GeoModel, Bratislava, CD. Gordon, L.J., Peterson, G.D., Bennet, E.M., 2008. Agricultural modifications of hydrological flows create ecological surprises. Trends in Ecology and Evolution 23 (4) 211–219. Guyomard, H., Le Bris, K., 2004. Multilateral Agricultural Negotiations and Multifunctionality: Some Research Issues. ENARPRI Thematic Network on Trade Agreements and European Agriculture, Policy Brief, Brussels (4). Haberlandt, U., Klo¨cking, B., Krysanova, V., Becker, A., 2001. Regionalisation of the base flow index from dynamically simulated flow components – a case study in the Elbe River basin. Journal of Hydrology 248, 35–53. Hanzel, V., 2003. Hydrogeolo´gia regio´nu Kysu´c [Hydrogeology of the Kysuce Region]. Podzemna´ voda 9 (2) 46–65 (English abstract). Harmon, M.E., Franklin, J.F., Swanson, F.J., Sollins, P., Gregory, S.V., Lattin, J.D., Anderson, N.H., Cline, S.P., Aumen, N.G., Sedell, J.R., Lienkaemper, G.W., Cromack, K., Cummins, K.W., 2004. Ecology of coarse woody debris in temperate ecosystems. Advances in Ecological Research 34, 59–234. Holko, L., 2010. Voda v krajine a povodne [Water in landscape and floods]. Urbanita 22 (4) 20–24. Holling, C.S., 1992. Cross-scale morphology, geometry, and dynamics of ecosystems. Ecological Monographs 62 (4) 447–502. Hvitved-Jacobsen, T., Vollersten, J., Nielsen, A.H., 2010. Urban and Highway Stormwater Pollution. Taylor Francis Group, Boca Raton, USA.
209
Kra´sny´, J., 1993. Classification of transmissivity magnitude and variation. Ground Water 31 (2) 230–236. Leeper, G.W., Uren, N.C., 1993. Soil Science: An Introduction, 5th ed. University Press, Melbourne, Australia. Lepesˇka, T., 2010a. Integrovany´ manazˇment povodı´ v horsky´ch a podhorsky´ch oblastiach [Integrated River Basin Managent in Mountain and Submontane Regions]. Technical University in Zvolen, Slovakia. Lepesˇka, T., 2010b. Hydric potential of landscape and integrated river basin management in mountain and submontane regions. Ecohydrology & Hydrobiology 10 (1) 13–24. Liniger, H., Weingartner, R., 1998. Mountains and freshwater supply. Unasylva 49, 39–46. Malı´k, P., Sˇvasta, J., Jetel, J., Hanzel, V., Gedeon, M., Scherer, S., Fendek, M., 2002. Hydrogeologicke´ pomery [Hydrogeology]. In: Miklo´s, L., Hrncˇiarova´, T. (Eds.), Atlas krajiny SR. MZˇP SR, Bratislava, SAZˇP, Banska´ Bystrica, p. 102. Marsalek, J., Jimenez-Cisneros, B.E., Malmquist, P.A., Karamouz, M., Goldenfum, J., Chocat, B., 2006. Urban Water Cycle Processes and Interactions. International Hydrological Programme – V, Technical Documents in Hydrology, vol. 78. UNESCO, Paris. Maser, C., Trappe, J.M., 1984. The Seen and Unseen World of the Fallen Tree. Department of Agriculture, Forest Service, Portland, USA. Midriak, R., 2008. Present-day retreat of slopes above the upper timberline in the Slovak part of the Western Carpathians. Geographia Polonica 9, 93–100. Miklo´s, L., Hrncˇiarova´, T. (Eds.), 2002. Atlas krajiny Slovenskej republiky [Landscape Atlas of the Slovak Republic]. MZˇP SR Bratislava, SAZˇP, Banska´ Bystrica, Slovakia. Mitsch, W.J., Gosselink, J.G., 2000. Wetlands, 3rd ed. John Wiley & Sons Inc., New York, USA. Montgomery, D.R., 2007. Soil erosion and agricultural sustainability. Proceedings of the National Academy of Sciences 104 (33) 13268– 13272. Ne´methy, P., 2003. Hydrogeologicke´ pomery okolia projektovanej voda´renskej na´drzˇe Tichy´ potok [Hydrogeological settings of surroundings of projected drinking water reservoir Tichy´ Potok]. Podzemna´ voda 9 (1) 52–59 (English abstract). Peck, A.J., Wiliamson, D.R., 1987. Effects of forest clearing on groundwater. Journal of Hydrology 94, 47–65. Schueller, T.R., 1987. Controlling Urban Runoff: A Practical Manual for Planning and Designing Urban BMPs. Publication No. 87703. Metropolitan Washington Council of Governments, USA. Slovak Environmental Agency, 2004. GIS CORINE Landcover 2000 Shapefile. SAZˇP, Banska´ Bystrica. ˇ ovy´ch sita´ciı´ na Slovensku v Solı´n, L’., 2008. Analy´za vy´skytu povodn obdobı´ rokov 1996–2006 [Analysis of floods occurrence in Slovakia]. Journal of Hydrology and Hydromechanics 56 (2) 95–115. ˇ ovej hrozby maly´ch povodı´ Solı´n, L’., 2011. Regiona´lna variabilita povodn na Slovensku [Regional variability of flood threat in small basins of Slovakia]. Geographical Journal 63, 29–52. Sˇa´lek, J., Mala´, E., Sˇtencel, M., 2002. Netradicˇnı´ zpu˚soby rˇesˇenı´ vodnı´ho hospoda´rˇstvı´ krajiny [Unconventional solutions of landscape’s water management]. In: Kozova´, M., Pavlicˇkova´, K., Barka, I. (Eds.), Nove´ trendy v krajinnej ekolo´gii [New trends in Landscape Ecology]. Comenius University, Bratislava, (English abstract), pp. 363–372. ´ PU ´ Sˇa´ly, R., Midriak, R., 1995. Water erosion in Slovakia. Vedecke´ pra´ce VU 19 (1) 169–175. Zachar, D., 1982. Soil Erosion. Developments in Soil Science, Vol. 10. Elsevier. Zalewski, M., 2000. Ecohydrology – the scientific background to use ecosystem properties as management tools toward sustainability of water resources. Ecological Engineering 16, 1–8. Zalewski, M., Wagner, I., 2005. Ecohydrology – the use of water and ecosystem processes for healthy urban environments. Ecohydrology & Hydrobiology 5 (4) 263–268. Zalewski, M., Janauer, G., Jola´nkai, G. (Eds.), 1997. Ecohydrology. A New Paradigm for the Sustainable Use of Aquatic Resources. UNESCO, Paris. Zhao, K., He, C., 2001. Wetland types, functions and conservation in China. Chinese Geographical Science 11 (4), 300–305.