Water for Life-Education for Water STUDYING SELECTED AREAS -VONARSKO LAKE 3rd Transnational Meeting 13th-17th June, 2009 Romania Klemen Prah Andreja Nekrep
1 GENERAL DATA - part of Panonian Slovenia - river Sotla means political border (SLO/CRO; EU/not EU) - in the year of 1980 was founded 6,5 kilometers long artificial Vonarsko lake (purpose: flood protection, drinking water); very polluted river Sotla and small water discharge in the year of 1988 was the lake emptied; today: flood protection and ideas about revitalization)
2 MAP
3 NATURAL VALUES - river Sotla natural value (hydrological, geomorphologic and ecosystem values) typical lowland river plenty of meanders and ox-bows deep river bed with steep banks - Vonarsko lake - presence of sediment with huge amount of organic nutritive substances - importance of swamp ecosystems (biodiversity, water retention, selfpurification) - swamp vegetation community types: types in (dried) ox-bows and small hollows vodna leča (Lemna minor) water fluctuating ecosystems (autumn and spring flood area) združba dresni in metlik (Polygonum sp.-chenopodium sp.) združba dresni in trodelnega krpača (Polygonum sp.- Bidens tripartite) rižolica (Leersia oryzoides) kostreba (Echinocloa cruss-gallii) pekinška vrba (Salix babylonica) ostri in lisičjerepi šaš (Carex acuta-c. vulpine) združba plazečega petoprstnika in kodrastolistne kislice (Potentillo reptans-rumex crispus) združba navadne krvenke in pisanega čužka (Lythrum salicaria-phalaris arundinacea) združba pisanega čužka ali pisane in rdeče vrbe (Phalaris arundinacea-salix purpurea) temporary wetlands influence of groundwater navadni trst (Phragmites australis) rogoz (Typha latifolia, T. angustifolia) aquatic weeds - wet meadows (immigrants from the age after the year 1500) zlata rozga (Solidago gigantea) (North America) deljenolistna rudbekija (Rudbeckia laciniata) (North America) oljna bučka (Echynocistis lobata) (North America) navadni ščir (Amaranthus retroflexus) (North America)
ambrozija ali žvrklja (Ambrosio artemisiifolio) (North America) Verlotov pelin (Artemisia verlotiorum) (southwest China) žlezasta nedotika (Impatiens glandulifera) (India, Himalaya) tree groves vrbe: rdeča (Salix purpurea), bela (S. alba), krhka (S. fragilis), mandljasta (S. triandra), beka (S. viminalis) - birds regularly nesting of endangered species: wet and flooded meadows: kosec (Crex crex) natural and flooded river bed: vodomec (Alcedo atthis), mokož (Rallus aquaticus), mali martinec (Actitis hypoleucos) overgrowing areas: rečni cvrčalec (Locustella fluviatilis), kobiličar (Locustella naevia), rjava penica (Sylvia communis), rjavi srakoper (Lanius collurio) presence of endangered species that nest in neighborhood: sršenar (Pernis apivorus), bela štorklja (Ciconia ciconia), črna štorklja (Ciconia nigra), pivka (Picus canus), smrdokavra (Upupa epops) presence of other species that nest in neighborhood and nourish on Vonarsko lake: siva čaplja (Ardea cinerea) migration corridor for many species kmečka lastovka (Hirundo rustica), črnoglavka (Sylvia atrcapilla), taščica (Erithacus rubecula), kos (Turdus merula), vijeglavka (Jynx torquilla), veliki detel (Dendrocopos major), plavček (Parus caeruleus) etc. - dragonflies (at least 21 species): modri bleščavec (Calopteryx virgo), prodni studenčar (Cordulegaster heros), Prodni modrač (Orthetrum cancellatum) etc. - amphibians and reptiles: gorski urh (Bombina variegata), zelena rega (Hyla arborea), navadna krastača (Bufo bufo), zelena žaba (Rana esculenta), martinček (Lacerta agilis), zelenec (Lacerta viridis), belouška (Natrix natrix) etc. - mammals: srnjad (Capreolus capreolus), lisica (Vulpes vulpes), poljski zajec (Lepus europaeus), polh (Glis glis), podlesek (Muscardinus
avellanaruis), pižmovka (Ondatra zibethica), mala podlasica (Mustela vulgaris), velika podlasica (Mustela erminea) etc. - geological values
4 CULTURAL VALUES - old country house - churches - intercultural relations (Slovenia-Croatia)
5 ECONOMIC AND SOCIAL IMPACTS - one of most polluted rivers in Slovenia - bad chemical condition and moderate biological condition (in Rogaška Slatina) - not good enough quality of water for new lake 5.1 POINT PRESSURES - influence of cities Rogaška Slatina (tourism, industry), Rogatec (industry) and Hum na Sutli (industry; Croatia) 5.2 DISPERSED PRESSURES - intensive agriculture (7% of catchment area of the lake; fields, gardens, vineyards, orchards) and urban areas (8,9% of catchment area of the lake) 5.3 HYDROLOGIC AND MORFOLOGIC PRESSURES - taking away of water from the river - morphologic modification of the river (dams building, river bed straightening, river bed canalizing, longitudinal and transversal profile modification) - disadvantages of the Vonarsko lake accumulation: the dam prevents water animals from moving oscillation of water discharge below the dam causes damages of many animal species artificial periodic lake bothers natural development of vegetation
6 STATISTICAL TABLES Table 1: Chemical condition of the river Sotla in Rogaška Slatina between years 2002-2006 (Source: Agencija RS za okolje). Measuring point Year 2002 Year 2003 Year 2003 Year 2005 Year 2006 Rogaška BAD BAD BAD BAD BAD Slatina CONDITION CONDITION CONDITION CONDITION CONDITION Table 2: Biological condition of the river Sotla in Rogaška Slatina between years 2001 and 2005 (Source: Agencija RS za okolje). Measuring Year Year Year Year Year point 2001 2002 2003 2004 2005 Rogaška 3 3 2-3 2-3 2 Slatina Legend: 1-the best condition, 4-the worst condition Table 3: Percentage (%) of built and intensive agricultural land on the drainage area of Vonarsko lake (Data source: Ministrstvo za kmetijstvo, gozdarstvo in prehrano). Type of dispersed impact Percentage of land (%) Built land 8,9 Intensive agricultural land 7,0 Total 15,9
7 LOCAL INHABITANTS OPINION 1. Sort from 1 to 4 the importance of Vonarsko lake (1-the most important, 4 the less important): richness of biodiversity (swamp habitat) tourism-recreational destination educational destination flood protection (other) 2. Which are the most negative impacts on the area of Vonarsko lake? 3. What kind of development of the Vonarsko lake area do you support? (encircle the letter before one answer): a) self-overgrowing in the meaning of renaturation b) self-overgrowing in the meaning of renaturation and development of educational and scientific tourism c) re-ponding and restoration of tourism infrastructure d) re-ponding and development of educational and scientific tourism e) (other) 4. What is your proposal for future development of Vonarsko lake area?
8 PHOTOS Slika 1: Vonarsko lake in 80-ies. Slika 2: Vonarsko lake at Vonarje dam in 80-ies.
Slika 3: Vonarsko lake today in winter.