Studies Regarding Aridity Phenomenon in Timis County Romania

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Studies regarding aridity phenomenon in Timi County,Romania

Rare Hlbac-Cotoar1

Abstract: Drought and the two associated phenomenas

(aridity and desertification) represent problems which

were very studied in the last period. In the last 55 years,

temperature around Timisoara increase with 0.7C and

the precipitation were reduced. Taking in consideration

and other factors as human impact and soils

characteristics, it can be observe especially in the north-

western part of Timi County the appearance of aridity

phenomenon.

This paper presents an assessment regarding the aridity in

western part of Romania, Timi County, taking in

consideration two indicators based on precipitation and

temperature: De Martonne and Lang. Using these two

indexes, were created and will be presented two maps.

Keywords: aridity, indicators, De Martonne, Lang, maps

1. INTRODUCTION AND GENERALASPECTS

The last century presents us that the humaninfluence about environment had materialized not onlythrough pollution, but especially by provoking climaticchanges at global level, changes which affect us more or

less. An important problem of our days, generated bythese climatic changes, is represented by drought andthe associated phenomenas aridity and desertification.

On 17 June 1994, at Paris, was adopted theConvention to Combat Desertification (CCD),

convention which became operatively in December1994. The basis of this convention is the Resolution47/188 of United Nations General Assembly from 1992,result of the United Nations Conference onEnvironmental and Development from Rio de Janeiro(1991). [1]

Romania adheres to CCD in 1997 by adoptingthe Law 629/1997. Also, at national level, was adoptedThe Government Decision 474 from 01.04.2004regarding the foundation, organization and function of

National Committee for Drought, Land Degradation andDesertification Control.

In Romania, the problem of drought wasconfirmed from many years. More than 2.8 millionhectares of agricultural fields presents a tendency ofdesertification. At the same time, drought affects almostthe entire Romanian agricultural fund. Timi County,situated in the western part of Romania, know atransition period, from humidity excess to humiditydeficit because of a long period with intensive drainage.The lack of humidity in soils is more evident in the

north-western part of this county. [1]A continuous decreasing of precipitations and,

in the same time, the temperature increasing can beobserved in the next figures.

Figure 1 Precipitations in western part of Romania [2]

1 PhD Stud. Eng., Politehnica University of Timiora, Hydrotechnical Engineering Faculty, [email protected]


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Figure 2 A comparison between temperatures from 2003 and 2004 and the normal for the respective period [2]

2. TIMI COUNTY CLIMATETimi County is situated in the western part ofRomania, with a total surface of about 8.700 Km2. Theterritory is represented by a moderated continental

temperate climate with Mediterranean influences. Ascan be seen from the following image, all the forms ofrelief are represented in this county.

Figure 3 Timi County geographical map [8]In Timi County were identified regional climates foreach type of relief forms. The areas which presents

periods with humidity deficit can be identified with 4from the mentioned regional climates situated on low

plains and high plains. The climate from SnnicolaulMare area can be characterized through a reducedquantity of precipitations, specific to steppe. Because of40 years with intensive drainage, on a large surface,water table level decrease dramatically. Biled-Banlocclimate presents humidity deficit (drought periods)

during summer and autumn. Timioara area appears onmany maps as a region with severe periods of drought.The quantity of precipitations in this region overruns600 mm. Gh. Iano and co. identify only one periodwith humidity deficit in the autumn. [5, 6] Orioara isthe most important region from the humidity deficit

point of view. It is the pole of drought for this county.The area can be characterized as an aridity one, all thehydrothermal indicators presenting low values. [5]


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3. ARIDITY ASSESSMENT. DE MARTONNEAND LANG INDICATORS.For aridity assessment can be used two

indicators, De Martonne and Lang, but with the mentionthat both of them presents some advantages anddisadvantages. These indicators use two natural climaticfactors: precipitation and temperature as you will see intheir formulas.

Formula for De Martonne indicator:

10+

=

T

PIM

(1)

Where P represents annual average precipitations and T represents the annual averagetemperature.

Aridity assessment using De Martonne indicatorValues Assessment0 .. 5 Arid climate5 .. 20 Half-arid climate

20 .. 30 Half-wet climate30 .. 55 Wet climate

The advantages of using this indicator are:allow the delimitation of arid and half-wet climates;

monthly indicator makes a good differentiation for theareas affected by drought. There are and somedisadvantages as: this indicator is not adequate for coldmountain forestry areas and presupposes valuesmeasured in standard meteorological stations. [3]

Formula for Lang indicator:

T

PIL= (2)

Where P and T had the same significances as inDe Martonne formula

Aridity assessment using Lang indicatorValues Assessment0 .. 20 Arid climate20 .. 40 Mediterranean climate40 .. 70 Half-arid climate70 .. 1000 Wet climate

Regarding this indicator, the advantage of using it is that

Lang indicator allows the delimitation of climates inplain (agricultural) areas. It cant be used in mountainforestry areas and cannot be applied using monthlyvalues [3].

4. STUDIES REGARDING ARIDITY FOR TIMI COUNTY AND THE RESULTS INTERPRETATIONTable 3 Values of De Martonne and Lang indicators for some areas from Timi County and their assessment [4, 5]No. Meteorological

stationAverage*

precipitationAverage*

TemperatureDe Martonne1

coefficientLang2

coefficientAssessment

1Assessment

21 Beba Veche 521 10,9 24,92 47,79 1 12 Teremia Mare 552,3 10,8 26,55 51,13 1 2

3 Snnicolau Mare 541,4 10,8 26,02 50,12 1 24 Jimbolia 560,1 10,7 27,05 52,34 1 25 Periam 530,3 10,7 25,61 49,56 1 16 Crpini 610,2 10,7 29,47 57,02 2 27 Cenei 540,5 10,7 26,11 50,51 1 28 Grniceri 619,7 10,7 29,93 57,91 2 29 Timioara 601 10,6 29,17 56,69 2 2

10 Ghiroda 631 10,9 30,19 57,88 3 211 Banloc 600,6 10,7 29,01 56,13 2 212 Liebling 586,6 10,6 28,47 55,33 2 213 Reca 615,4 10,6 29,87 58,05 2 2

14 Orioara 544 10,5 26,53 51,8 1 215 Giarmata 590,8 10,8 28,4 54,7 2 216 Maloc 617,3 10,7 29,82 57,69 2 217 Buzia 639,9 10,7 30,91 59,8 3 218 Lugoj 690,7 10,6 33,52 65,16 3 319 Cliciova 641,9 9,7 32,58 66,17 3 320 Bunea Mare 629,6 9,6 32,12 65,58 3 321 Coteiu de Sus 771,8 8,4 41,94 82,1 4 422 Huzeti 864,9 9,1 45,28 95,04 4 423 Visag 647,4 10,4 31,73 62,25 3 3


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24 Izvin 582 10,4 28,53 55,96 2 225 Dudetii Noi 577 10,6 28,01 54,43 2 226 Dinia 550,1 10,8 26,45 50,94 1 227 Hitia 640 10,7 30,92 59,81 3 228 Tormac 620 10,8 29,8 57,4 2 229 Deta 602 10,7 29 56,26 2 230 Denta 602 10,7 29 56,26 2 2

31 Para 620 10,7 29,95 57,94 2 232 Gvojdia 676,2 10,5 32,99 64,4 3 333 Ndrag 1040 8,8 55,32 118,18 4 434 Fget 836 9,8 42,31 85,34 4 435 Peciu Nou 628 10,8 30,19 58,14 3 2

* Values from these columns are forbidden to be used without the permission of Meteorological CentreBanat-Criana Timioara**Values, from positions 1 to 23, are annual average temperatures and precipitations for period 1950-1999 while thevalues from 24 to 35 are representative for the interval 1896-1973.

Table 4 Personal aridity assessment for Timi County climate using De Martonne indicatorPersonal aridity assessment using De Martonne indicator

Values Assessment24 .. 28 Half-wet climate with increased risk at aridization28 .. 30 Half-wet climate with low risk at aridization30 .. 40 Half-wet climate with tendency to wet climate

> 40 Wet climate

Table 5 Personal aridity assessment for Timi County climate using Lang indicatorPersonal aridity assessment using Lang indicator

Values Assessment40 .. 50 Half-arid climate50 .. 60 Half-arid climate with periods of half-wet climate60 .. 70 Half-wet climate without risk of aridization

> 70 Wet climate

The maps representing aridity degree for Timi County,using De Martonne indicator, were realized taking inconsideration table 3, table 6 and figure 4. Areas with ahigh vulnerability at aridization are situated in north-western part of Timi County and in northern part,Orioara area, at the border with Arad County. Onthese territories, the precipitation level is low,temperatures increased and the soils had a small easilywater capacity. I consider that the mentioned areas must

be integrated in first class of vulnerability with a half-wet climate, having an increased risk at aridization. Thesecond class of vulnerability at aridization isrepresented by the areas situated in central part and

southern part of Timi County. A few parts from thisterritory present an increased risk to drought because ofsoil characteristics. Lands from first and second classhad a plain relief, so they present a tendency of climatefrom half-wet to half-arid and even arid if the actualtrend of climatic changes will continue. Territories witharidity values between 30 and 40 are generally situatedon high plains or hills and do not present risk ataridization, we can say that the most of them had a

climate more closely to wet climate. Finally, areas withan aridity value bigger than 40 are situated on hills andmountains and their climate is wet.Taking in consideration Lang indicator, there are onlytwo zones with half-arid climate: Beba Veche andPeriam. This indicator presents large areas with half-arid climate but a big part of them had periods withhalf-wet climate and even wet climate. Unfortunately, inthe last 10 years, the climate in Timi County becamesometimes unpredictable, given us numerous surprises,generally not pleasant. Eastern part from this county,situated on high forms of relief, can be integrated inhalf-wet and wet climate accordingly to Lang indicator.

A general assessment, taking in consideration bothindicators, even there are some differenced betweenthem, presents high and medium aridity risk in north-western part of our county, the vulnerability to this

phenomenon decreasing during the approaching to highforms of relief, situated in eastern part of Timi County.The impact of aridity upon lands is influenced and bysoils characteristics as it is easily water capacity.


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Figure 4 Soils map of Timi County [7]

Next table will present the class of vulnerability forsome soils, according to National Strategy and ActionProgram Concerning Desertification, Land Degradationand Drought Prevent and Control, elaborated using theresults obtained by Forest Research and ManagementInstitute (FRMI), Research Institute for Soil Science andAgrochemistry (RISSA), National Company NationalInstitute of Meteorology, Hydrology and WaterManagement (NC-NIMHWM), Studies and Designing

Institute for Land Improvement (SDILI), NationalInstitute of Research Development for EnvironmentProtection (NIRDEP), Research and TechnologicalEngineering Institute for Irrigations and Drainage,Bneasa-Giurgiu (RTEID), Research Institute of LifeQuality, Research Institute for Grains and TechnicalCrops Fundulea (RIGTC) and Research and ProductionInstitute for Grass Cultivation, Mgurele Braov(RPIGC). [1]

Table 6 Soils vulnerability to drought [1]

Soil type Class of vulnerabilitySoils with good easily available water capacity (on flat lands, moderately vulnerable to drought)KASTANOZEMSCHERNOZEMSCLAY-ILLUVIAL AND CAMBIC CHERNOZEMSMOLLIC CLAY-ILLUVIAL BROWN SOILSREDDISH BROWN SOILS

IIIIIIIIIII

On sloping lands (more vulnerable to drought)KASTANOZEMSCHERNOZEMSCLAY-ILLUVIAL AND CAMBICE CHERNOZEMS

II

I IISoils with smaller easily available water capacity (more vulnerable to drought)LITHIC KASTANOZEMSMOLLIC EU-MEZOBAZIC BROWN SOILSSOLONETZ

VERTISOLSLITHOSOLSPSAMOSOLSLAMELAR PSAMOSOLSCOARSE TEXTURED ALLUVIAL SOILS

III

I IIIIIII

Soils with shallow ground water (less vulnerable to drought)CHERNOZEMS, FREATIC PHASEGLEY SOILSHUMIC-GLEY SOILSMEDIUM TEXTURED ALLUVIAL SOILSFINE TEXTURED ALLUVIAL SOILS

IIIII IIIII III

IIIII III


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Figure 5 Aridity map for Timi County using De Martonne indicator (Hlbac, 2006)


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Figure 6 Aridity map using De Martonne indicator. Vulnerable areas to drought (Hlbac, 2006)


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Studies Regarding Aridity Phenomenon in Timis County Romania