Download
1 / 16
160 likes | 181 Views
Explore the influence of climate change on European lakes, with a special emphasis on the Balkan region. Discover how lakes integrate climate and catchment changes, affecting temperatures, ice regimes, water balances, and more. Understand the unique impacts on deep, temperate, shallow, boreal, Arctic, and mountain lakes, with a spotlight on Southeastern Europe's diverse climatic conditions. Gain insights into expected climate changes and impacts in various subregions, from Mediterranean to mountainous areas. Consider the significance of anthropogenic activities compared to climate effects on the lakes. Delve into the potential effects of climate change on karstic lakes and underground water bodies.
E N D
The influence of climate change to European lakes, with a special emphasis in the Balkan region Esko Kuusisto Finnish Environment Institute 25.5.2004
NUMBER OF LAKES IN EUROPE: • TOTAL NUMBER AROUND 1.4 MILLION • RUSSIA 700 000 • FENNOSCANDIA 600 000 • REST OF EUROPE 100 000 • SOUTHEASTERN EUROPE 10 000 • Larger than 100 km2: 150 • Russia 51 • Fennoskandia 76 • Rest of Europe 23 • Southeastern Europe 5
LAKES AND CLIMATE CHANGE: • Lakes are excellent integrators of changes in climate and catchment conditions • many complexities and interactions • Most essential changes: • temperature regime • ice regime • changes in water balance • changes in water use
DEEP, TEMPERATE LAKES: • Winter overturn may be suppressed • monomictic lakes may become oligomictic • increased risk of anoxic conditions and eutrophication • Warmer surface water • increased evaporation • Changes in catchment conditions may be important
SHALLOW, TEMPERATE LAKES: • Higher risk of eutrophication • Reduced fish catches • Decrease of inflows, higher evaporation • lower water levels • increased salinity
BOREAL LAKES: • Shortening of the ice-cover period • better oxygen conditions • Stronger summer stratification • Increased eutrophication in sensitive lakes
ARCTIC LAKES: • Simple and labile ecosystems • sensitive to changes • Melting of permafrost, increase of evaporation • some lakes may completely disappear
MOUNTAIN LAKES: • Many of them are hydrologically and biologically iso-lated • no escape routes; species have to adapt to new climate • Enhancement of UV-radiation • clear water maximizes the risk!
LAKES IN SOUTHEASTERN EUROPE: • Large variations in present climatic conditions: • Mean temperature in January –10…+10°C, in July +5…+25°C • Annual precipitation 700…1200 mm, local extremes 350…4600 mm
EXPECTED CHANGES IN EUROPE’S CLIMATE: • Considerable variation in scenarios • TEMPERATURE: • an increase of 0.1…0.4ºC per decade, greatest warming in S and NE Europe • PRECIPITATION: • in winter, most of the continent gets wetter, 1…4% per decade • in summer, southern Europe may get drier, up to 5% per decade
EXPECTED IMPACTS: 1. MEDITERRANEAN SUBREGION - Adriatic coast, Greece, SW lowlands of the Black Sea • Very high water temperature in summer • algal and water quality problems • Deacreased inflows, increased evaporation • shallow lakes may become intermittant • reservoirs suffer water losses
IMPACTS, continued: 2.NORTHERN LOW-LANDS - Hungary, E Croatia, C Serbia, S and E Romania, Moldova • Occurrance of ice-free winters may increase • Adverse water balance changes • intermittancy • increased salinity
IMPACTS, continued: 3. MOUNTAINEOUS REGIONS - Carpathians, Dinaric Alps, numerous smaller ridges and plateaus • Ice-cover season gets shorter • Increased erosion may cause sedimentation and water quality problems • The importance of mountain lakes in water supply may increase
FINAL REMARKS: • DIVISION INTO SUBREGIONS IS NECESSARILY A SIMPLIFICATION • e.g. the region of Lake Ohrid has Mediterranean, continental and mountaineous characteristics • DIRECT ANTROPOGENIC INFLUENCE INTO THE LAKES MAY GREATLY EXCEED THE CONSEQUENCES OF CLIMATE CHANGE
KARSTIC LAKES? • UNDERGROUND LAKES – ARE THEY IMMUNE TO CLIMATE CHANGE? • NO; THEIR WATER BALANCE AND ECOLOGY MAY ALSO BE AFFECTED!
