Climate Change a trend of increasingly frequent droughts in Kakheti Region (East Georgia) Accepted Manuscript Climate Change a trend of increasingly frequent droughts in Kakheti Region (East Georgia)[.]
Accepted Manuscript Climate Change: a trend of increasingly frequent droughts in Kakheti Region (East Georgia) M Meladze, G Meladze PII: S1512-1887(17)30022-2 DOI: 10.1016/j.aasci.2017.02.011 Reference: AASCI 89 To appear in: Annals of Agrarian Sciences Received Date: 12 August 2016 Accepted Date: 17 November 2016 Please cite this article as: M Meladze, G Meladze, Climate Change: a trend of increasingly frequent droughts in Kakheti Region (East Georgia), Annals of Agrarian Sciences (2017), doi: 10.1016/ j.aasci.2017.02.011 This is a PDF file of an unedited manuscript that has been accepted for publication As a service to our customers we are providing this early version of the manuscript The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain ACCEPTED MANUSCRIPT Annals of Agrarian Science vol 15, no 1, 2017 Climate Change: a trend of increasingly frequent droughts in Kakheti Region (East Georgia) Corresponding Corresponding author: Maia Meladze meladzem@gmail.com RI PT M.Meladze, G.Meladze Georgian Technical University, Institute of Hydrometeorology 150a, David Agmashenebeli Ave., Tbilisi, 0112, Georgia Received: 12 August 2016; Accepted: 17 November 2016 EP TE D M AN U SC ABSTRACT Following the global warming, in Kakheti Region, in East Georgia (by municipalities), the trends of changes (increase or decrease) in agro-climatic characteristics for the development of agricultural crops were identified Such changes result in the prolonged vegetation period, increased sum of temperatures and mostly, decreased sum of precipitations Based on the latter indicators, a trend of a decreasing index of the hydrothermal coefficient is observed evidencing more frequent droughts with low or moderate intensity The data of the 60-year-long period of meteorological observations (1949-2008) were divided into two 30-year-long periods in order to compare them It was found that in the second period (1979-2008), the indices of a hydrothermal coefficient in all municipalities (except Kvareli) are decreased in the active vegetation period (VI-VIII) The dynamics of the course of a hydrothermal coefficient is shown with trends Based on the many-year meteorological observation data (1949-2008) in different municipalities, the sums of active annual temperatures (>10ºC) and atmospheric precipitations were calculated On the background of global warming, the repeated nature of droughts of different types was identified The nomograms of the frequency of the droughts of the type typical to the study object and moisture evaporation have been drafted Based on the sums of the annual active temperatures (>10ºC) and atmospheric precipitations, an equation to calculate the hydrothermal coefficient was given A correlation between the date of the temperature rising over 10ºC and the sum of temperatures was identified (r=0.80) and a regression equation to forecast different types of droughts was designed Against frequent droughts following the global warming, it is recommended to take relevant adaptation measures to avoid negative events AC C Keywords: Climate change, Active temperature, Atmospheric precipitation, Hydrothermal coefficients, Droughts, Earth climate -1 Introduction The Earth climate has been changing for the last half billion years with the alternating warm and cold periods The reason for such changes has been an abnormal action of volcanoes, the change of the rotation axis in relation to the Sun, change in the configuration of the continents and other phenomena The second part of the past century was characterized by the onset of the Global Warming, also confirmed by the studies of the World Meteorological Organization (WMO) at the beginning of the XXI century The global climate change means increase of average long-term air temperature on the Earth In modern times, the climate change is mainly the result of the anthropogenic impact [1], which is seen as wrong industrial activity of a human and intense use of natural resources causing so called ,,greenhouse effect” in the atmosphere It is hard to predict the future, but based on the experts opinion (in 1988, with this aim, the UNEP (the UN ACCEPTED MANUSCRIPT Study area TE D M AN U SC RI PT Environmental Program) and the world meteorological services formed an intergovernmental expert group, the IPCC (International Panel on Climate Change)) Unless the intensity of carbon dioxide drops in the future, then their concentration will reach a hazardous limit in the XXI century [2, 3] Following the view that the global warming in the near-surface air layer of the Earth is mainly resulted from the anthropogenic impact, it becomes necessary to take preventive measures under a joint agreement among the most world countries, including Georgia, in order to ensure the rational use of the natural resources: oil, coal, forests, etc., as when burnt, together with the great amount of warmth, they release carbon dioxide, as well The latter retains warmth in the atmosphere and supports the temperature increase in the near-surface air layer In addition, the industrial and transport emissions are to be reduced significantly [4, 5] Consequently, unless the emissions are limited, the amount of carbon dioxide in the air may double by 2020-2050 leading to the temperature increase by 2-3ºC [6] It does not matter whether we take strict measures to reduce the greenhouse gases or not, these gases will accumulate in the atmosphere However, the intensity of accumulation will be much less than in case of anthropogenic load The impact of global warming in the world is already evidenced by a temperature increase by 0.6ºC In the east part of Georgia, the air temperature is increased by 0.5ºC on average [7] what must be taken into account, as by 2030-2050, the further increase may constitute 1-2ºC creating unfavorable conditions for many branches of the country, including the agrarian sector Temperature growth in the vegetation period will significantly increase the sum of active temperatures of the agricultural crops development, make droughts more frequent, etc [8-11] Therefore, at present, development of the correct strategy of the climate change mitigation and adaptation measures is very topical The mitigation options for the climate change implies developing such alternative sources of power, as wind energy, solar energy and safe nuclear energy [12-14] Adaptation is the ability of a system to adapt to the climate change (changeable climate) to minimize the expected harm, employ the advantage of the existing prospects or fight its possible outcomes It covers the measures in different fields to minimize the undesirable impact caused by the global climate change For instance, the measures to adapt to the climate change in the agricultural sector imply the perfection of the methods of irrigation of the plots of field, selection of the crops more stable to the climate change, etc AC C EP Kakheti region covers mostly a plain and partially, a mountainous relief The region is located at 300-1900 m or higher above sea level From the north, the region is bordered by Caucasioni Ridge, from the north-west it is bordered by Mtskheta-Mtianeti region, from south-west it is bordered by Kvemo Kartli region and from the east and it is bordered by Azerbaijan Kakheti is a very important region if considering that it produces a range of agricultural products The favorable local soil and climatic conditions allow gaining rich harvest of cereals, as well as autumn and spring wheat, barley, maize, etc The people in Kakheti successfully grow different vine varieties popular in the world The existing agro-climatic conditions support successful growth of essence and technical oil cultures The environment also supports fruit-growing, vegetable-growing, melons and gourds, cattle-breeding, poultry-raising and development of other agricultural branches [15] It should be noted that most area of Kakheti region lacks moisture, but is well-provided with warmth Therefore, it is necessary for farmers to be aware of the agroclimatic characteristics on the territories of Kakheti districts to use them to choose the right kind of farming by considering the existing agricultural and climatic conditions Results and discussion A trend of changing (increasing or decreasing) agro-climatic indices (sums of active temperatures and atmospheric precipitations, hydrothermal coefficient and duration of the vegetation period) ACCEPTED MANUSCRIPT Table Agro-climatic indicators in 30-year-long periods period (years) Akhmeta Gurjaani Telavi Omalo (Akhmeta) Sagarejo EP Kvareli 7.IV 3.IV 2.IV 30.III 18.IV 17.IV 6.IV 2.IV 1.VI 31.V 14.IV 10.IV 3.IV 1.IV TE D Dedoplistskaro 1949-1978 1979-2008 ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, data of data of transition transition air temp air temp t>10°C t10°C (IV-X) M AN U Municipality (meteostation) SC RI PT caused by the global warming has been identified in the vegetation period These indicators mostly determine the degree of development of agricultural crops, their productivity, quality, etc For the municipalities of Kakheti region (Akhmeta, Gurjaani, Dedoplistskaro, Telavi, Omalo (Akhmeta), Sagarejo, Kvareli), the data of many-year meteorological observations (1949-2008) (sums of daily air average monthly temperatures and atmospheric precipitations) of the National Environmental Agency were used These data were used to calculate the sums of active annual temperatures (>10ºC) and atmospheric precipitations, and the latter values were used to calculate the hydrothermal indices The above-mentioned long-term 60-year-long period (1949-2008) covers the initial period of global warming, the 1970-80s, the moment of onset of the impact of global warming on the above-listed values In this connection, the data of the 60-year-long meteorological observations were divided into two 30-year-long periods in order to identify the changes in some or other values in the two periods The first period covers the time from 1949 through 1978, and another period covers the rime from 1979 through 2008 (Table 1) 31.X 3.XI 3.XI 4.XI 21.X 22.X 31.X 2.XI 16.IX 20.IX 25.X 27.X 3.XI 5.XI 3735 3930 3996 4073 3289 3430 3784 3897 1373 1515 3430 3550 3996 4118 active temp sum >10°C (VIVIII) 2010 2063 2102 2125 1921 1976 2022 2066 1190 1263 1935 1971 2093 2136 atmospheric precipitations sum (VIVIII) HTC index (VIVIII) 241 233 243 229 195 175 260 246 267 261 238 225 297 312 1.2 1.1 1.1 1.0 1.0 0.9 1.3 1.2 2.2 2.0 1.2 1.1 1.4 1.5 AC C It turned out that in the second period, the dates of the temperature rising over 10ºC start early at every location, while the temperature decrease below 10ºC starts late making the vegetation period longer, increasing the sums of active temperatures and slightly decreasing the atmospheric precipitations at every location except Kvareli municipality In the second period, the indices of a hydrothermal coefficient were decreased in the active vegetation period (VI-VIII) at all locations (except Kvareli) The dynamics of the course of the hydrothermal coefficient is shown with trends evidencing the rising trend of the sums of active temperatures in the region A trend of decreasing sums of atmospheric precipitations is observed at all locations (Kvareli and Dedoplistskaro are an exception) In addition, a hydrothermal coefficient in the plant active vegetation period (VI-VIII) is reduced at all locations (except Kvareli) Below we give the dynamics of the course of the hydrothermal coefficient for Kakheti municipality (Fig 1) ACCEPTED MANUSCRIPT M AN U SC RI PT a) Akhmeta TE D b) Gurjaani AC C EP c) Dedoplistskaro d) Telavi M AN U SC e) Omalo (Akhmeta) RI PT ACCEPTED MANUSCRIPT g) Kvareli AC C EP TE D f) Sagarejo Fig The dynamics of hydrothermal coefficients in Kakheti municipalities ACCEPTED MANUSCRIPT AC C EP TE D M AN U SC RI PT The territory of Kakheti is not well provided with the atmospheric precipitations in the vegetation period (Kvareli is an exception with 700 mm of atmospheric precipitations) The lack of precipitations is even severer in the plant active vegetation period (VI-VII-VIII), when the harvest is formed, the fruit buds are conceived, etc In this period, following the decreased amount of precipitations and increased sums of temperatures, the trend of the reducing index of the hydrothermal coefficients is observed what supports a more frequent nature of such a hazardous meteorological phenomenon, as drought Drought is characterized by high temperatures and little atmospheric precipitations, plus low soil productivity and little soil humidity, water moisture deficit in the air, frequent winds (with the velocity of 2-4 m/sec) The joint action of these factors in the plant active vegetation period may hamper the growth and development of agricultural crops In terms of their prolonged action, the plants may not only get damaged, but they may perish as well Drought is an ecological problem and is characterized by severity, frequency, duration and seasonality Depending on seasons, they distinguish autumn, spring and summer droughts The latter are particularly hazardous for the agrarian sector, as the process of the plant growth and development is active in this period and the demand for water is consequently increased A crop with a normal course of growth in the natural environment easily resists the variations in the daily water supply However, in order to resist quite a long droughty period, it must have certain properties (drought resistance) Therefore, it is essential to be aware of the peculiarities of the plant habitat and drought duration and intensity The same crop in different climatic conditions is affected by the drought in different ways Similarly, in terms of the same habitat, the crops with different ecological properties may respond differently to the drought Some cultures may not decrease transpiration during the droughts and continue it simultaneously with evaporation The negative outcomes of the drought may be as follows: fallen agricultural harvest, irrigation and industrial water deficit, food deficit, problems of dehydration, origination of erosive sites and dust storms in the desertificated and eroded areas Following the above-mentioned, on the example of Dedoplistskaro, as per the data of many-year meteorological observations (1949-2008) (daily air average monthly temperatures, atmospheric precipitations) of the National Environmental Agency, the sums of active temperatures (>10ºC) and atmospheric precipitations were calculated The indices of hydrothermal coefficients were also identified and the dynamics of their course depending on the trend was drafted by using these factors [16] The sum of temperature at the outset (1949) was 3208ºC and it was 3496ºC at the end of 2008 In the 60-year-long period, an increase per 10 years was 49ºC, and an increase of the atmospheric precipitations was up to 28 mm, making up to mm every ten years As for the hydrothermal coefficient, it is characterized by a decreasing trend (Figure 1), [17] In the vegetation period, for the optimal development of agricultural crops, the territory of Dedoplistskaro is not well-provided with the atmospheric precipitations (445 mm) The provision is even less (185 mm) in the plant active vegetation period (VI-VII-VIII) Following the global warming, our goal was to identify the cases of different types of droughts and create the basis to forecast them The conditions of the vegetation period (humid or arid) were assessed by means of a hydrothermal coefficient of G.Selianinov commonly used and approved in the fields of agrometeorology and agro-climatology, with water balance of the precipitations evaporated from the fallen atmospheric precipitations conventionally equals to 1.0 Under such terns, the plants are more or less provided with many-year moisture (for 10 to 12 days for annual crops and 18-20 days for perennial crops) The water balance of the hydrothermal coefficient less than 1.0 is the sign of the lack of humidity, i.e drought, while when this value exceeds 1.0, there is abundant humidity in the area [18] In this connection, the sums of active temperatures and atmospheric precipitations were used to identify the indexes of the hydrothermal coefficient and properties of different types of droughts (Table 2) ACCEPTED MANUSCRIPT Table Characteristics of different types of droughts and moisture evaporation balance according to the HTC, depending on the sums of temperatures (>10ºC) and atmospheric precipitations (in the VI-VIII period) in Kakheti average intensity 1.1-1.3 ΣT°C ΣP(mm) 2014 241 intense 1.7-1.9 RI PT less intense AC C EP TE D M AN U As the Table suggests, following the 60-year-long (1949-2008) observations, different types of droughts and moisture evaporation balance on the territory of Kakheti can be described The data in the Table also allow specifying their forecasts further In the given period, for example Dedeoplistskaro 33 cases of different types of droughts making 55% are fixed, including cases of less intense droughts (15%), 17 cases of droughts with average intensity (28%), cases of intense droughts (8%) and cases of very intense droughts (3%) For the last 30 years, the cases of less intense droughts have decreased by 3% and the cases of droughts with average intensity has decreased by 7%, but the cases of very intense droughts has increased by 7% Following the goal described above, the nomograms showing the frequency and moisture evaporation balance of the given types of droughts on the territory of Kakheti were drafted (Fig 2) Fig Reoccurrence of different types of droughts (HTC ( ) 1.0) As the Figure suggests, the reoccurrence of the droughts can be identified in every 10 or more years Such identification needs the average values of droughts and humidity balance As per the index of hydrothermal coefficient, it is 0.6 and 1.5 (for Dedoplistskaro and Shiraki, respectively) For example, if we want to fix the reoccurrence of droughts with average intensity on the territory of Dedoplistskaro, between the mean value of droughts (HTC - 0.6) and the droughts of average intensity (HTC - 0.7) in Figure 2, we draw the difference (making 0.1) Right of the abscissa in the Figure, a straight dotted line is erected from point 0.1 up to the crossing point with the curve, ACCEPTED MANUSCRIPT TE D M AN U SC RI PT with corresponding 70% in this point of the Figure meaning that it will reoccur by 70%, or times in every ten years Different types of droughts and reoccurrence of the moisture balance will be determined similarly Identification by means of the given rule allows the agrarian workers and farmers to receive the information about the reoccurrence of some or other type of drought in every ten or more years, and if necessary, take agro-technical measures against the drought to support the trouble-free growth and development of agricultural crops and maintain rich harvest The indices of a hydrothermal coefficient to determine the different types of droughts mostly depend on the sums of active temperatures and atmospheric precipitations The more the sum of active temperatures is, the more intense the evaporation from the fallen atmospheric precipitations is, and the index of a hydrothermal coefficient decreases As a result, quite shortly, a plant experiences the lack of moisture and drought is inevitable In this connection, indices of a hydrothermal coefficient were calculated by means of the sums of active temperatures (>10ºC) and atmospheric precipitations given with the relevant equation in Figure U=-0.00005T+0.0054P+0.0862 In the equation, U - is the index of a hydrothermal coefficient, T - is the sum of active temperatures 45 days from the date of the temperature rising above 10ºC (in the VI-VIII period), P - is the sum of atmospheric precipitations (mm) in the same period EP Fig Dependence of a hydrothermal coefficient on the sums of active temperatures (>10ºC) and atmospheric precipitations (mm) (in the VI-VIII period) AC C The Figure clearly shows their dependence on the given factors Therefore, it is advisable to develop the method to forecast the sum of temperatures in the way similar to that given in the work [19] to use for forecasts in the VI-VIII period Consequently, for the territory of Dedoplistskaro, after identifying the association between the date of the temperature rising >10ºC and the sum of temperatures by using the method of mathematical statistics accepted in agrometeorology, a correlation (r=0.80) given with a regression equation in Figure was identified: T=-18.57n+3359, where T - is the sum of active temperatures (45 days from the date of the temperature rising above 10ºC, in the VI-VII-VIII period), n - is the number of days from February to the date of the temperature rising above 10ºC RI PT ACCEPTED MANUSCRIPT SC Fig Connection between the dates (n) of the temperature rising above 10ºC and the sum of temperatures >10ºC one month and a half after these dates (the VI-VIII period) TE D M AN U Forecasting method: suppose, in 2016, on the territory of Dedoplistskaro, the expected sum of temperatures as per the forecast equation is 2050ºC The obtained forecasted temperature must be compared to the sum of temperatures characterizing the different types of droughts in Table The value it coincides with is, or gives a difference f 50-80ºC indicates the expected type of the drought in the current year If it is a drought of a less intense, a sum of forecasted temperature and sum of the atmospheric precipitations typical to the given type of drought is used to specify it By inserting them as predictors in the equation to calculate the index of the hydrothermal coefficient, index of 0.91 (rounded to 0.9) characterizing the expected drought of a less intense is obtained, indicating the given type of drought The forecast is done for the first five-day period of April or rarely, of May, with its balance of up to months The agro-meteorological forecast of the different types of droughts is important for agricultural workers and farmers, as such awareness of the future forecast will help them to get ready and overcome the droughts Conclusions and recommendations AC C EP Based on the study accomplished in Kakheti region, east of Georgia, a change (increase or decrease) of agro-climatic characteristics (sums of active temperatures and atmospheric precipitations, hydrothermal coefficient) in the vegetation period caused by global warming was identified As a result, increasing frequency of the different types of droughts was identified Following the biology of the agricultural crops, the temperature increase in Georgia will lead to significant changes; however, it is possible to avoid negative effects by selecting and realizing the scientifically proved efficient measures Disturbed water balance hampers the development of agricultural crops At locations with high reoccurrence of droughts, it is necessary to take different agro-technical measures to mitigate the negative effects In particular, alongside with the traditional agricultural crops, selection of drought-resistant crops is paid much attention in the world In such a case, a possible temperature increase (global warming) is particularly important to consider It is desirable to diminish the inter-row distance for some annual crops, grow windbreaking belts or make terraces over the slopes with the inclination of >10º Such arrangements reduce the water flow and total moisture use Such measures as irrigation, cultivation, mulching and the like must be employed to a maximum extent and with a maximum efficiency Using the modern irrigation technologies, including drop irrigation and the like is particularly important An integrated agriculture management system is expedient to introduce, as this will lead to the development and wide-scale introduction and application of new technologies Agrarian ACCEPTED MANUSCRIPT education of the society is noteworthy in respect of taking vulnerability, adaptation and mitigation measures because of the expected climate changes AC C EP TE D M AN U SC RI PT References [1] Paris Agreement under the United Nations framework Convention on Climate Change Conference, Paris (2015), p 33 [2] The Third National Communication Climate Change of Georgia, UNDP, (2015), p 287 (in Georgian) [3] The Second National Communication Climate Change of Georgia, UNDP (2009), p 230 (in Georgian) [4] Bruce J.P The Atmosphere of the Living Planet Earth Geneva: WMO, 705 (1990), p 42 [5] Hefling G.I Anxiety 2000 Ed ,,Think", M., (1990), p 271 (in Russian) [6] Budiko M.I The climate in the past and the future Publ ,,Gidrometeoizdat’’, L., (1980), p 351 (in Russian) [7] Tavartkiladze K Begalishvili N., Tsintsadze T., Kikava A Influence of Global Warming on the Near-Surface Air Temperature Field in Georgia Bulletin of The Georgian National Academy of Sciences, vol 6(3), (2012), pp 55-60 [8] Meladze M Principles of Agroecology Publ ,,UNIVERSUL’’, Tbilisi, Georgia (2015), p 240 (in Georgian) [9] Mavi H.S., Tupper G.J Agrometeorology: Principles and Applications of Climate Studies in Agriculture Binghamton, NY, USA (2004), p 364 [10] Adamenko T., Anaman K., Gomes R., Jonson G Agrometeorology Related to Extreme Events World Meteorological Organization, Geneva-Swizerland, No 943, (2002), p 152 [11] Impacts of Desertification and Drought and Other Extree Meteorological Events Prepared by Gathara S.T Geneva-Switzerlend (2006), p.88 [12] Workbook on Climate Change Impact Assessment in Agriculture Prepared by Roger E Rivero Vega Camaguey Meteorological Centre (2008), p.149 [13] Modern Challenges of Ecological Meteorology and Climatology Editor-in-Chief Menzhulin G Publ ,,NAUKA’’, Saint-Peterburg (2005), p 218 [14] Kenneth G.Hubbard Agricultural Climatology Journal of the American Association of State Climatologist, vol.1(2), (2007), pp 1-9 [15] Meladze G., Meladze M Agroclimatic Resources of Eastern Regions of Georgia Publishing House ,,UNIVERSAL’’, Tbilisi, Georgia (2010), pp 25-46 (in Georgian) [16] Meladze M., Meladze G Global Warming and Increasing Tendency of Development Agriculture Basic Indices and Drought in Kakheti Transactions of international conference of the Academy agricultural sciences of Georgia (2015), pp 232-236 (in Georgia) [17] Meladze G., Meladze M Influence of Global Warming on Agroclimatic Indices of agriculture and Intensity of Droughts in Kakheti Region, East Georgia Bulletin of The Georgian National Academy of Sciences, vol.10(1), (2016) pp.197-104 [18] Meladze G., Meladze M The Agroclimatic Indices Change Caused by Global Warming in Kvemo Kartli Region Proceedings of international conference TSU, Institute of Geography, Geographical society of Georgia (2015) pp 214-219 (in Georgia) [19] Davitaia F Prediction of provide with heat and some of the problems of seasonal development nature ,,Gidrometeoizdat’’, M., (1964), p 132 (in Russian) ...ACCEPTED MANUSCRIPT Annals of Agrarian Science vol 15, no 1, 2017 Climate Change: a trend of increasingly frequent droughts in Kakheti Region (East Georgia) Corresponding Corresponding author:... (in Georgia) [17] Meladze G., Meladze M Influence of Global Warming on Agroclimatic Indices of agriculture and Intensity of Droughts in Kakheti Region, East Georgia Bulletin of The Georgian National... great amount of warmth, they release carbon dioxide, as well The latter retains warmth in the atmosphere and supports the temperature increase in the near-surface air layer In addition, the industrial