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Water Supply on Croatian Islands – the impact on tourism. Ante Blaće, anblace@unizd.hr Branimir Vukosav, bvukosav@unizd.hr Robert Lončarić, rloncar@unizd.hr Department of Geography University of Zadar 14 th European seminar on geography of water Cagliari, 26 June – 7 July 2011.
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Water Supply on Croatian Islands – the impact on tourism Ante Blaće, anblace@unizd.hr Branimir Vukosav, bvukosav@unizd.hr Robert Lončarić, rloncar@unizd.hr Department of Geography University of Zadar 14th European seminar on geography of water Cagliari, 26 June – 7 July 2011
Croatia: • 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: • 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 Lakeon 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
Number of tourists on the large Kvarner Islands from 1999 to 2008
Main problem – water shortage during the high touristic season e. g. Krk Island Population: Winter: ~17-20,000 domestics Summer: 20,000 domestics 50,000 weekend visitors 50,000 tourists 120,000 total e. g. Novalja on Pag Island 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
Number of tourists on the small Kvarner Islands from 1999 to 2008
Threats: • Sea-level rise → • Consequences • 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 • 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