Occurrence of Dry and Wet Periods in Altitudinal Vegetation Stages of West Carpathians in Slovakia: Time-Series Analysis 1951-2005 J. Hrvoľ,, J. J Škvarenina,, J. J Tomlain, J. Škvareninová,, P. Nejedlík
Vegetation stages /Zlatnik,, 1976/ 1st Oak 2nd Beech-Oak 3rd Oak-beech 4th Beech 5th Fir-beech 6th Spruce- fir-beech 7th Spruce 7th Spruce & 8th Mountain pine 5 % of terr. 15 24 21 21 9 2 1
Vegetation stages. Oak. Beech-oak. Oak-beech. Beech. Fir-beech. Spruce-beeh-fir. Spruce. Dwarf pine. Alluvial communities
Where are we? Area
50000km 2, mean altitude 450 m a.s.l., 41% of territora covered by forests
Stations
Drought Natural Climate Variability T I M E D u r a t i o n Precipitation deficiency High temp., high winds, (amount, intensity, low relative humidity, timing) greater sunshine, less cloud cover Reduced infiltration, runoff, deep percolation, and ground water Increased evaporation recharge and transpiration Soil water deficiency Plant water stress, reduced biomass and yield Reduced streamflow, inflow to reservoirs, lakes and ponds; reduced wetlands, wildlife habitat Meterological Drought Agricultural Drought Hydrological Drought Economic Impacts Social Impacts Environmental Impacts Socioeconomicenvironmental Drought
Methodology Evaluated parameters /annual and seasonal values/: -Precipitation, P [mm] -Potential evapotranspiration, E 0 [mm] -Actual evapotranspiration, E [mm] -Relative evapotranspiration, E/E 0 [%] -Drought index, E 0 /P [-]
Definitions E 0 maximal possible evapotranspiration under the given energy condition /no water shortage/ E the evapotranspirarion under the real energy and water supply conditions E = E o.w/w o W - water stored in the upper soil layer of 1 m depth W o - the critical value above which E equals E o
Average annual values of precipitation (P), potential (Eo( Eo), actual evapotranspiration (E), drought index (Eo( Eo/P) and relative evapotranspiration (E/Eo Eo) ) at chosen localities of Slovakia for in 1951-2005 Meteorological station H [m a.s.l.] P [mm] Eo [mm] E [mm] E/Eo [%] Eo/P [ - ] Vegetation stage Hurbanovo 115 537 748 432 58 1,44 1 st Oak Myjava 375 671 627 450 72 0,96 2 nd Beech-Oak Kamenica n. C. 178 722 644 501 78 0,92 3 rd Oak-beech Plaveč 488 693 522 451 87 0,78 4 th Beech Červený Kláštor 474 755 507 457 90 0,69 5 th Fir-beech Oravská Lesná 780 1114 456 432 95 0,42 6 th Spruce- fir-beech Tatranská Javorina 1020 1253 422 412 97 0,35 7 th Spruce Štrbské Pleso 1360 995 435 407 94 0,45 7 th Spruce & 8 th Mountain pine
Annual trend analysis (1950 2005) of E/Eo Eo and (Eo/P). Probability level *p* < 0.1, **p < 0.05, ***p < 0.01, ****p < 0.001, n.s.. not significant Meteorological station E/Eo = f (years) Trend Eo/P = f (years) Trend Hurbanovo ** aridity *** aridity Myjava ** aridity n.s. - Kamenica n. C. n.s. - n.s. - Plaveč **** humidity **** humidity Červený Kláštor * humidity ** humidity Oravská Lesná n.s. - n.s. - Tatranská Javorina n.s. - **** humidity Strbske Pleso n.s. - * humidity
The dependence of relative evapotranspiration annual values (E/Eo Eo) on altidude [m a.s.l.].] in Slovakia in 1951-2005. /logaritmic scale/ 100 90 E/Eo [%] 80 70 60 y = 13.507Ln(x) + 0.8658 R 2 = 0.8149 50 40 0 200 400 600 800 1000 1200 1400 altitude [m]
The dependence of drought index annual values (Eo( Eo/P) on altidude [m a.s.l.].] in Slovakia in 1951-2005 2005. /logarithmic logarithmic scale/. 1.6 1.4 1.2 Eo/P 1.0 0.8 0.6 0.4 0.2 0.0 y = -0.3957Ln(x) + 3.1773 R 2 = 0.8935 0 200 400 600 800 1000 1200 1400 altitude [m]
The course of annual values of (E/Eo Eo) in Hurbanovo in 1951-2005 - linear trend and polynomial of 3rd order 100 90 E/Eo [%] 80 70 60 y = 0.0002x 3-1.1098x 2 + 2177.1x - 1E+06 R 2 = 0.1234 50 40 y = -0.1555x + 365.87 R 2 = 0.0709 30 1950 1955 1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 year
The course of annual values of (Eo/P) in Hurbanovo in 1951-2005 - linear trend and polynomial trend of 3rd order Eo/P 2.8 2.6 2.4 2.2 2.0 1.8 1.6 1.4 1.2 1.0 0.8 0.6 0.4 0.2 y = 0.0062x - 10.821 R 2 = 0.0974 y = 3E-06x 3-0.0204x 2 + 40.639x - 27050 R 2 = 0.1174 1950 1955 1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 year
The course of annual values of (E/Eo Eo) in Plaveč in 1951-2005 - linear trend and polynomial of 3rd order 100 90 80 E/Eo [%] 70 60 50 40 30 y = 0.2293x - 366.67 R 2 = 0.2207 y = -0.0003x 3 + 1.7462x 2-3465.2x + 2E+06 R 2 = 0.2634 1950 1955 1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 year
The course of annual values of (Eo/P) in Plaveč in 1951-2005 - linear trend and polynomial trend of 3rd order Eo/P 2.8 2.6 2.4 2.2 2.0 1.8 1.6 1.4 1.2 1.0 0.8 0.6 0.4 0.2 y = -0.0047x + 10.107 R 2 = 0.1901 y = 5E-06x 3-0.0323x 2 + 64.027x - 42360 R 2 = 0.2242 1950 1955 1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 year
Conclusions - Relative evapotranspiration and drought index, were used to characterise the energetic and humidity conditions of Slovakia There are two different climatic zones /temperate and boreal/ The relative evapotranspiration shows values as from 97 % in the northern mountainous regions, to 58 % in the Danubian lowland. A significant increase in the severity of drought was identified only in the Danube Lowland (1st Oak vegetation stage) and in Zahorská Lowland (2nd Beech-Oak vegetation stage); a significant trend of increasing humidity in mountains and in the northern part of East Slovakia.