Download Ante Blaće, Branimir Vukosav, Robert Lončarić, University of Zadar

Ante Blaće, [email protected]
Branimir Vukosav, [email protected]
Robert Lončarić, [email protected]
Department of Geography
University of Zadar
14th European seminar on geography of water
Cagliari, 26 June – 7 July 2011
Croatia:
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Central European and Mediterranean country
Area: 56.538 sq km
Territorial Sea: 31.479 sq km
Population: 4.49 million (2009 estimated)
Capital: Zagreb (population 800.000)
Independent: since 1991
Croatian archipelago:
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1246 islands and islets
3,259 sq km (5.8% of Croatian territory)
Population: 121,606 (2001 census;
2.74% of the total Croatian population)
Only 79 islands > 1 sq km
47 inhabited islands
 Traditional islands’ economy: vine and olive growing,
fishery
 Rapidly increasing population in the late 19th and
early 20th century
 Onset of mass emigration due to the crisis of the
traditional economy → depopulation of the islands;
process still present
 Inadequate water supply systems – main obstacle
for islands’ economical development
Natural features
Geology
 Dinaric karst on Adriatic Carbonate Platform (AdCP)
 Karst procesess during numerous emersions
 Last emersion – LGM (-135 m)
 Mesosoic and Paleogene limestones and dolomites
 Eocene flysch and marl
 Quaternary sediments (Pleistocene loess)
 Importance of less permeable
sediments for surface hydrography
Climatic settings
 Mediterranean climatic influence
(Köppen’s classification)
 Csa climate
temperate humid Mediterranean
climate with hot summer
 Cfa climate
temperate humid climate
with hot and relatively humid summer
 Cfb climate
temperate humid climate
with warm and relatively humid
summer
 Csb climate
Mediterranean climate
with warm summer
Precipitation: 700-1500 mm/a
• karst relief – general lack of surface
water…
…but…
Vransko jezero Lake on the Cres Island
- the largest lake on Croatian islands
- the largest accumulation of potable water in Croatia
- formed in karst depression
- bottom of the lake about 61 m below the mean sea level
- maximum depth is 74.5 m
- surface of the lake is 5.75 km2
- contains roughly 220 million m3 of water
Lake near Njivice – Krk Island
- surface 0.6 km2
- bottom of the lake about 7 m below the
mean sea level
- catchment area 12 km2
- water level varies 1 - 2 m
- used for the water-supply from 1963
- max. pumping capacity 5 l/s
Ponikve – Krk Island
- karst depresion (2200 × 50-300 m)
- bottom of the valley –
Quaternary sediments 44 m thick
- surface 0.87 km2
- contains 2.65 mil. m3
- depth of the lake 6 m
- pumping capacity up to 84 l/s
Large islands:
 Few islands have adequate local water sources (e. g.
Islands of Krk, Cres, Lošinj, Vis)
 Others depend on water from the mainland
 Islands with substantial water resources developed
modern economy based on mass tourism
 Positive impact of tourism on demographic processes
700000
600000
Broj turista
500000
400000
Krk
Cres
Rab
Lošinj
300000
200000
100000
0
1999.
2000.
2001.
2002.
2003.
2004.
2005.
2006.
2007.
Godine
Number of tourists on the large Kvarner Islands from 1999 to 2008
2008.
25000
Broj stanovnika
20000
15000
Krk
Lošinj
Cres
Rab
10000
5000
0
1857.
1869.
1880.
1890.
1900.
1910.
1921.
1931.
Godine
1948. 1953. 1961.
1971.
1981.
Population of the large Kvarner Islands from 1857 to 2001
1991.
2001
Main problem – water shortage during the high touristic season
e. g. Novalja on Pag Island
e. g. Krk Island
Population:
Winter: ~17-20,000 domestics
Summer: 20,000 domestics
50,000 weekend visitors
50,000 tourists
120,000 total
ca. 3,500 permanent inhabitants
> 50,000 people during the summer
Water consumption during the year on Krk Island
Small inhabited islands:
 Water supply from local sources, questionable water quality, salt-water
intrusion during the summer
 Lack of link with the waterworks on the larger neighbouring islands or on the
mainland
 Many small islands depend on water-supplying ships
 Water shortage – the main obstacle for touristic development; negative impact
on demographic trends
 Possible alternative solutions:
desalination
wastewater treatment
rainwater usage
water from submarine springs (vrulje)
 Most solutions are not cost-effective
1600
1400
1200
Broj turista
1000
Unije
Susak
Ilovik
800
600
400
200
0
1999.
2000.
2001.
2002.
2003.
2004.
2005.
2006.
2007.
2008.
Godine
Number of tourists on the small Kvarner Islands from 1999 to 2008
1800
1600
1400
Broj stanovnika
1200
Ilovik
Unije
Susak
Vele Srakane
Male Srakane
1000
800
600
400
200
0
1857.
1869.
1880.
1890.
1900.
1910.
1921.
1931.
1948. 1953.1961.
1971.
1981.
1991.
Godine
Population of the small Kvarner Islands from 1857 to 2001
2001.
Threats:
Sea-level rise →
Consequences
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changes in surface water quality and groundwater characteristics
increased coastal erosion and coastal habitats
increased flood risk and potential loss of life and property
impacts on agriculture and aquaculture through decline in soil and water quality
loss of nonmonetary cultural resources and values
loss of tourism, recreation, and transportation functions
Demographic and economical pressure →
Consequences
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increased water consumption
water shortages during summer
decreased water quality
high risk of pollution
heavy impact on overall economical and social development
Conclusions:
 Relatively high precipitation (700 mm – 1500 mm)
 Karst relief – water rapidlly infiltrates underground
 Large islands
- significant water resources
- development of modern tourism-based economy
- positive demographic trends
- seasonality of water consumption
- possible water shortages during summer months
 Small islands
- inadequate local water resources
- low quality of water
- underdeveloped tourism
- negative demographic trends
 Potential threats: sea-level rise; demographic and
economical pressure
Thank you for your attention!
Zlatni Rat beach – Brač Island