AN ANALYSIS OF WATER SCARCITY PHENOMENONS AND WATER DEMANDS FOR AGRICULTURAL AREAS FROM WESTERN PART OF ROMANIA USING DIFFERENT PROGRAMS

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1 Proceedings of the 13 th International Conference on Environmental Science and Technology Athens, Greece, 5-7 September 2013 AN ANALYSIS OF WATER SCARCITY PHENOMENONS AND WATER DEMANDS FOR AGRICULTURAL AREAS FROM WESTERN PART OF ROMANIA USING DIFFERENT PROGRAMS STANA O. 1 and HALBAC-COTOARA-ZAMFIR R. 1 Hydrotechnical Engineering Department, Politehnica University of Timisoara, Romania raresh_81@yahoo.com EXTENDED ABSTRACT The last century presents us that the human influence about environment had materialized not only through pollution, but especially by provoking climatic changes at global level, changes which affect us more or less. An important problem of our days, generated by these climatic changes, is represented by drought and the associated phenomena s aridity and desertification. The changes in Earth s global climate show a trend of increasing average air temperature and causing drastic changes in hydrologic cycle. As a result, the vegetation period is expected to become shorter and an even more irregular distribution of precipitation will occur, both from year to year. Essentially, the periods of semi-drought or even drought conditions are going to become more frequent. In Romania, the problem of drought was confirmed from many years. More than 2.8 million hectares of agricultural fields presents a tendency of desertification. At the same time, drought affects almost the entire Romanian agricultural fund. Timiş County, situated in the western part of Romania, know a transition period, from humidity excess to humidity deficit because of a long period with intensive drainage but also due to the effects of climatic changes. The lack of humidity in soils is more evident in the northwestern part of this county. This paper presents an analysis of water scarcity and water demands for agricultural areas from western part of Romania using two programs: CropWat 8.0 and Hidroesta. The first program, CROPWAT 8.0, allow the users to calculate crop water requirements and irrigation requirements based on soil, climate and crop data. We can also use this program to develop irrigation schedules for different management conditions. This program can also be used for the calculation of scheme water supply for varying crop patterns and to evaluate farmers irrigation practices and to estimate crop performance under both rainfed and irrigated conditions. HidroEsta is a tool that facilitates and simplifies the laborious calculations, in this case being mainly used for determining the evapotranspiration calculations (through different methods as Thorthwaite, Blaney-Criddle, Penman, Hargreaves) and water balance calculations. This paper will focus especially on extreme western part of Timis County, the area around Sannicolaul Mare City and which covers the Aranca plain and will try to present an analysis of water scarcity phenomenons (by analyzing evapotranspiration, water balance variation, different other indicators) and water demands for agricultural areas. Keywords: climatic changes, water-table levels, Hidroesta, Timis, Arad, dry periods, climograms, land reclamation and improvement 1. INTRODUCTION 1.1 A general overview on some concepts Water scarcity is defined in many cases as the situation where water availability in a region presents values below 1000m 3 /person/year. United Nations, Department for

2 Economic and Social Affairs define water scarcity as the point at which the aggregate impact of all users impinges on the supply or quality of water under prevailing institutional arrangements to the extent that the demand by all sectors, including the environment, cannot be satisfied fully [8]. Even there are significant opinions in drawing a typology of water scarcity, scientists agreed of defining water scarcity as a relative concept generated both by nature and humanity. Another concept which is more often present in the last decades is water stress. Water stress presents an imbalance on medium term, when the water quantities per person and per year are less than 1700 m 3 [8]. Water stress is influenced by nature (reduced volume of precipitations) but also by humans through an improper management of water resources or due to careless policies on water (e.g. water courses pollution). Water shortage is defined by FAO as an absolute shortage where levels of available water do not meet certain defined minimum requirements without making any other references to the time factor [3]. Meanwhile, water shortage is defined only in terms of comparison (between minimum requirements and existing resources) without having attached a reference value. Using these terms (generally and mainly having a man-made character) in comparison with natural phenomenon (dryness, drought, aridity), we can define some links, from temporal point of view, between dryness and water shortage (short-time defined elements), between drought and water stress (medium term) and between aridity and water crisis as long time defined concepts. All these terms are presented in this paper from a hydrologist point of view (a technical point of view). If we will pass in the social and economic sectors, water crisis may appear anywhere on scale time because in many areas, today, water crisis is not an issue of scarcity, but of access to fresh water. In this paper the authors studied some climatic indicators directed related to natural features of water scarcity. We study the phenomenon of dryness, periods of drought and the climatic tendency to aridity. 1.2 Brief description of analyzed area This paper will focus on studying the water scarcity phenomenon and agricultural areas water demands from extreme western part of Romania, area which includes the actual location of Sinnicolau Mare City and its surroundings. Figure 1 Sinnicolau Mare area (hydrographic and geographic) [10, 11] From geographic point of view, the analyzed area covers the Aranca River s hydrographic basin, a plain area. Aranca Plain is low subsidence plain of meadow and of divagation with a cone shape. Dominant elevation of the plain is m, some ridges rising to 90 m but at the border decrease to 77m. The slope is about 0.30, meaning that the plain is almost horizontal. Because of this type appears microform beds and abandoned meanders, surface drainage channels, fluvial and anthropogenic mounds [5, 7].

3 Climate falls under temperate continental climate with prevailing air masses of maritime and continental eastern origin plus hot air masses crossing the Mediterranean and cold polar air masses. Tropical circulation causes mild winters and significant amounts of rainfall and the summer one unstable weather with showers and thunderstorms. The hydrography of the analyzed area is the result of the combined action of climatic factors, morphology and geology. Land morphology influences the depth and groundwater drainage, climate and hydrography affect supply, drainage and groundwater level variations and geological factor determining the existence of phreatic layer and deep aquifers. Of these factors, only climatic factor is considered uniform throughout the area, other factors being different from one area to another [5, 7]. The region Aranca groundwater contributes to excess soil water, but only up to a depth of 2 m; starting from a 2.3 m depth, the groundwater has no influence on soil, but contributes to his water supply during drought. The channel water supply is from precipitation, groundwater springs and fountains of waters [5, 7]. Soils are related to rock, climate and vegetation and are very different. Soils in the Aranca area are presenting several common features. All soils have the same mother rock at the base, alluvium, and with small exceptions loess on higher sites. A main characteristic of the soil cover is the dynamics differentiated in time and space that results from natural conditions of formation and evolution. As a result of pedo-genetic processes there appeared a cover of mosaic-like soil, which is also seen in the main soil types identified in the area under study. We can find in this area large surface with Chernozem, Fluvisols, Vertisols and Pelosols [5, 7]. Figure 2 Groundwater depths in Aranca hydrographic basins (comparisons)

4 Figure 3 Precipitations quantities variations per seasons in Sinnicolau Mare area (Aranca hydrographic basin). Comparisons 2. WATER SCARCITY PHENOMENONS Following the definition from Encyclopedia of World Climatology we will observe that aridity is referring to the dryness of the atmosphere and can be defined as a function of a continuum of environmental factors as temperature, precipitation, evaporation, low vegetative cover etc. In order to quantify aridity for a specific area we must take into account at least three main factors: precipitation, temperature and evaporation. Nowadays aridity is quantified by using more than 50 indexes. We must have in mind that aridity indexes are generally considered from the standpoint of their eventual use [6]. Living in a society based on economical and social premises, recent researches were focused on aridity indexed for defining agricultural boundaries between arid and semiarid climates, boundaries on which UNESCO, FAO and WMO agreed that should be drawn where the lack of water makes dryland farming impossible. Currently, two of the most used indicators in describing the aridity are the aridity index (defined as the ratio P/ETP) which has been proposed by the UNCCD and the De Martonne indicator. The authors proposed an indicator for natural water scarcity analysis (based on the aridity index proposed by UNCCD and De Martonne indicator) which uses precipitation, temperature, potential evapotranspiration and the index of dry days based on the definition proposed by M. Nedealcov and modified by the authors. A dry day it was defined by M. Nedealcov as being a day when relative humidity is below 30% and temperature is higher than 25 0 C [4]. This index is proposed to be used for the period between April and September and was tested for Sinnicolau Mare area with good results. P WSCI ETP( T 10) 2 I DD For I DD we propose the following values according to the number of dry days in a month:

5 Table 1 Values proposed for I DD No. of dry days in a month I DD days days days 0.75 Less than 15 days 1 Using WSCI we can analyze a month from dryness point of view: Table 2 Months analysis using WSCI indicator WSCI values Type of month <0.25 Very dry month (VD) Dry month (D) Normal (N) > 2.5 Humid (H) We used this indicator for two years (2000 and 2010) to determine the month s dryness for the period between April and September. Table 3 Analysis of months from 2000 and 2010, Sinnicolaul Mare area, using WSCI index Year April May June July August September , , , , , , D VD D VD VD D , , , , , , N H N VD H N The values presented above are comparable with the results obtained with consecrated methods. Nevertheless, this indicator still needs further calibrations for more accurately climate analysis. 3. WATER DEMANDS FOR AGRICULTURE Cropwat and HidroEsta were both used to determine the water demands in agriculture. HidroEsta is a tool that facilitates and simplifies the laborious calculations, and the process of analyzing the wealth of information that must be performed in hydrological studies allowing determining the evapotranspiration calculations (through different methods as Thorthwaite, Blaney-Criddle, Penman, Hargreaves) and water balance calculations [1]. CROPWAT 8.0 for Windows is a computer program for the calculation of crop water requirements and irrigation requirements based on soil, climate and crop data. In addition, the program allows the development of irrigation schedules for different management conditions and the calculation of scheme water supply for varying crop patterns. CROPWAT 8.0 can also be used to evaluate farmers irrigation practices and to estimate crop performance under both rainfed and irrigated conditions [2]. We will take in study two years, 2000 and 2010, from which the first was considered to be very poor in precipitations and very hot while the second one was a humid one and with relative normal temperatures. In calculations we also considered the average values for a period of 30 years ( ). The selected crop, necessary to run the calculations with CropWat 8.0, is peas. The selected soil is a chernozem. CROPWAT 8.0 is more suitable for persons which intend to determine water demands in agriculture while HidroEsta will provide only a general image on water balance using as input data temperatures (there must be integer values higher than 0 o C) and precipitations

6 (only integer values). CROPWAT 8.0 allows negative values for temperatures and doesn t work only with integer values for both temperatures and precipitations. The results on water demands in agriculture obtained with CROPWAT 8.0 and HidroEsta are presented in the next tables and figures. Table 4 Crop Water Requirements table for peas, 2000, Sinnicolaul Mare area Month Decade Stage Kc ETc mm/day ETc Eff rain Irr Req May 2 INIT May 3 DEV June 1 DEV June 2 DEV June 3 MID July 1 MID July 2 MID July 3 LATE August 1 LATE August 2 LATE TOTAL Table 5 Irrigation schedule for peas, 2000, Sinnicolaul Mare area Date Day Stage Depl (%) Net Irr (mm) Gr Irr (mm) Flow (l/s/ha) INIT INIT INIT INIT DEV DEV DEV DEV DEV DEV DEV DEV DEV DEV MID MID MID MID MID MID MID MID MID MID MID MID MID MID MID

7 MID MID MID MID END END END END END END 18 Table 6 Crop Water Requirements table for peas, 2010, Sinnicolaul Mare area Month Decade Stage Kc ETc mm/day ETc Eff rain Irr Req May 2 INIT May 3 DEV June 1 DEV June 2 DEV June 3 MID July 1 MID July 2 MID July 3 LATE August 1 LATE August 2 LATE TOTAL Table 7 Irrigation schedule for peas, 2010, Sinnicolaul Mare area Date Day Stage Depl (%) Net Irr (mm) Gr Irr (mm) Flow (l/s/ha) INIT DEV DEV DEV DEV MID MID MID MID MID MID MID MID END END END END END END 24

8 Figure 4 A comparison between the irrigation requirements (2000 and 2010) for Sinnicolau Mare area (peas, chernozem) Figure 5 Water balance in Sinnicolaul Mare area (2000 and 2010). Values obtained with HidroEsta The results generated by these programs are correlated with other climatic researches which proven that 2000 was one of the driest years while 2010 was a normal one from climatic point of view, even a little more humid. While HidroEsta presents only a general view on water balance in agriculture, CROPWAT 8.0 is a better tool given being the outputs generated by this application. The water necessary in 2000 was three times higher than the amounts necessary for irrigation in 2010 for the same crop and on the same soil. 4. CONCLUSIONS For Sinnicolaul Mare, an analysis of the last 12 years, presents a tendency of climate from dryness to normal with some humid intervals. This area is covered by large surface drainage arrangements which were very necessary few decades ago when the groundwater presented high levels with negative impacts on agriculture. After a dry period, with low values of precipitations and when were created very good conditions for crop development, the actual tendency of precipitations volumes variation can lead again to the necessity of applying surface drainage and drainage works. Programs as CROPWAT 8.0 and Hidroesta are very useful in determining the variations of water balance and the crops water requirement. Providing very goods results in terms of evapotranspiration, irrigation requirements and their schedule, these applications prove to be useful tools for any person involved in agriculture domain. Considering that the global demand for water in agriculture will continue to increase over time and having in view the existent water scarcity in many agricultural areas, a sustainable management of water resources in agriculture must be implemented

9 everywhere even for the moment, in some areas, there is an appearance of water sufficiency. ACKNOWLEDGEMENT This work was partially supported by the strategic grant POSDRU 107/1.5/S/77265 (2010) of the Ministry of Labor, Family and Social Protection, Romania, co-financed by the European Social Fund Investing in people. REFERENCES 1. Bejar V.M. (2006) HidroEsta, Editorial Tecnologica de Costa Rica. 2. FAO (2006) CROPWAT 8.0, Natural Resources and Environment Department, URL: (accessed 02/03/2013). 3. FAO (1997) Proceedings Of The Second Expert Consultation On National Water Policy Reform In The Near East, Food And Agriculture Organization Of The United Nations, Regional Office For The Near East, Cairo. 4. Nedealcov M. (2010) Theoretical aspects in climate aridity evaluation in Republic of Moldova territory, URL: (accessed 15/02/2013) 5. Nedelcu R. (2008) The impact of hydroameliorative works and other sources on transborder waters quality from Banat hydrographical space, PhD Thesis, Politehnica University of Timisoara, Timisoara. 6. Oliver J.E. (2005) Encyclopedia of World Climatology, Springer. 7. The Monograph of Sinnicolaul Mare City, URL: (accessed 04/03/2013). 8. United Nations Department of Economic and Social Affairs, URL: (aceessed 06/03/2013) 9. United Nations Framework Convention on Climate Change (1992) URL: (accessed 15/02/2013). 10. URL: (accessed 02/02/2013). 11. URL: (accessed 02/02/2013).