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Cluj Dej Huedin Turda Vladeasa Baisoaramm

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precipitation period 5-9 days period >=10 days

Analysis of Dryness and Drought Periods in Cluj County, in the 1971-2000 Period

Irina BLAGA, Cornel BLAGA"Babeş-Bolyai" University, Faculty of Geography, Cluj-Napoca, Romania (blaga_irina@yahoo.com)“National Meteorological Administration, Romania”, Centre for Weather Forecasting, Cluj-Napoca

Cluj County is located in the northwestern part of Romania,

being crossed at the center by the 46˚50' north parallel and 23˚30'

longitude east.

DATA AND METHODS

The study of dryness and drought was based on daily, monthly, semester and annual precipitation from six weather stations in Cluj County; four in the hillside: Cluj-Napoca, Dej, Turda, Huedin, and two mountain stations: Baisoara and Vladeasa. The lack of rainfall was associated with maximum temperature distribution in the same period to highlight the dryness and drought phenomena.

The period 1971-1981 was characterized by excess precipitation, followed by a period of deficient rainfall, 1982-1994, when more drought years were reported (1982, 1983, 1986, 1990, 1992 and 1994). The years 1997-1999 were rainy, and 2000 was the driest year, when drought was widespread throughout the country, with different intensities.

REFERENCES:1.Bogdan, Octavia, Niculescu, Elena, (1995), Phenomena of dryness and drought in Romania

2.Croitoru, Adina-Eliza, Moldovan F., (2005), Vulnerability of Romania territory to climatic hazard

3.Dragota, Carmen-Sofia, Grigorescu, Ines, (2010), Climatic hazards in Bucharest metropolitan area

Due to global warming

trends, the number of warm

periods is increasing, as well

as the number of monthly

absolute maximum

temperatures.

ACKNOLEDGEMENTS:This work was possible with the financial support of the Sectoral Operational Programme for Human Resources Development 2007-2013, co-financed by the European Social Fund, under the project number POSDRU/107/1.5/S/76841 with the title „Modern Doctoral Studies: Internationalization and Interdisciplinarity”.

The western part of Cluj county is occupied by the Vladeasa, Gilau and High Mountain and the north eastern part of Trascau Mountains, the north-eastern district overlaps the Somes Plateau, and the southern and south-eastern part overlap the Transylvania Plain (Somes Plain and northwestern part of the Mures Plain)

Mean of rainfall during warm semester (April - September) and periods of dryness and drought

Mean of rainfall during cold semester (October - March) and periods of dryness and drought

In the case of the drought periods, the seasonal distribution for the hilly area stations reveals that their number is higher in the summer season than in the cold season, 14% at Turda, 28% at Cluj-Napoca, 50% at Huedin and 60% at Dej, due to the large number of days with high maximum temperatures which facilitate the reduction of atmospheric moisture. In the mountain region the trend is reversed with dry periods in winter having a higher number with 12.5% at Baisoara and 50% at Vladeasa, due to fewer days with convective precipitation.

CONCLUSIONS:

•The deficit of rainfall caused decreased river flow and reduced soil moisture thus affecting crops and increasing the demand for providing larger quantities of suitable irrigation water.

•The years with the lowest amounts of rainfall recorded were, in descending order, 2000, 1990, 1986, 1983.

•Long term severe drought in Cluj County territory was not evidenced.

Legend There is no tendency of increase/decrease in the number of periods of drought, but an alternation.

SPI Dej Cluj Turda Huedin Baisoara Vladeasa1971 -1.3 -0.3 -0.3 -0.9 0.8 -0.21972 0.0 0.7 0.7 -0.1 1.2 0.11973 -0.6 -0.7 -0.2 -0.2 0.6 0.61974 1.8 1.1 1.3 1.5 1.1 2.91975 0.0 -0.7 0.6 0.0 1.8 1.31976 -0.4 -0.4 -0.1 -0.5 0.1 1.31977 0.2 -0.8 0.0 0.8 0.8 1.21978 2.2 0.9 0.7 2.1 0.9 1.11979 0.4 -0.3 -0.4 0.2 -0.1 0.31980 1.7 2.0 2.1 2.1 0.3 1.51981 1.5 0.3 0.2 0.4 0.3 0.21982 -1.0 -0.4 -1.2 0.2 -1.6 -0.31983 -0.9 -2.1 -0.4 -1.0 -2.0 -0.61984 0.1 0.7 1.4 0.7 -0.1 0.11985 0.0 0.1 0.5 -0.3 0.5 -0.61986 -1.1 -1.4 -1.6 -2.0 -1.4 -0.81987 0.0 0.1 0.4 -0.5 -0.2 -0.71988 -0.1 -0.5 -0.1 0.1 -0.4 -0.71989 0.0 0.8 0.3 0.4 0.3 -0.41990 -1.6 -1.7 -1.3 -1.3 -1.4 -1.11991 -0.7 0.8 0.0 0.2 0.9 -0.31992 -0.9 -0.5 -1.2 -0.5 -0.6 -0.61993 -0.2 0.0 -0.2 0.0 -1.0 -0.71994 -0.4 -0.4 0.0 -1.4 -1.4 -1.11995 0.0 -0.1 -1.0 0.4 -0.1 0.01996 -0.6 0.3 0.2 0.5 0.5 -1.31997 1.4 1.6 0.1 -0.1 0.2 -0.21998 1.4 1.2 1.0 0.8 0.8 1.01999 0.5 1.4 1.5 0.6 0.8 -0.42000 -1.3 -1.6 -2.7 -2.1 -1.8 -1.8 The increase in the number of days with

tropical temperatures (T > 30° C) in the last decade of the period emphasized

the negative effects of drought.

< -2.5 exceptionally dry[-2.5, -2.1] excessively dry[-2.0, -1.6] very dry[-1.5, -1.1] dry

[-1, 1] normal[1.1, 1.5] rainy[1.6, 2.0] very rainy[2.1, 2.5] excessively rainy

> 2.5 exceptionally rainy