Trend Analysis of Meteorological Drought Using Standardized Precipitation Index for Allahabad
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International Journal of Civil Engineering and Technology (IJCIET) Volume 9, Issue 8, August 2018, pp. 14581465, Article ID: IJCIET_09_08_147 Available online at http://iaeme.com/Home/issue/IJCIET?Volume=9&Issue=8 ISSN Print: 0976-6308 and ISSN Online: 0976-6316 © IAEME Publication Scopus Indexed TREND ANALYSIS OF METEOROLOGICAL DROUGHT USING STANDARDIZED PRECIPITATION INDEX FOR ALLAHABAD Mohammed Shahique Sheeraz M.Tech. Student, Department of Civil Engineering, Sam Higginbottom University of Agriculture, Technology and Sciences, Allahabad, India Chandra Shekhar Mishra Asst. Professor, Department of Civil Engineering, Sam Higginbottom University of Agriculture, Technology and Sciences, Allahabad, India R.K. Pandey Professor, Department of Civil Engineering, Sam Higginbottom University of Agriculture, Technology and Sciences, Allahabad, India ABSTRACT Climate variability is the phenomenon where different factors can cause temperature to fluctuate around the average without causing the long-term average itself to change. The present study is carried out in order to study the statistical trend analysis of precipitation along with study of abnormal wetness and dryness over Allahabad district, India. A detailed investigation comprising of Standard Precipitation Index (SPI) of Allahabad district is carried out using monthly precipitation data over the period of 1967-2017. For Allahabad district standard precipitation index (SPI) values range from + 0.21 to – 1.91 indicating variation in precipitation over the period of 1967-2017. Key words: Allahabad, Climate Change, Drought, RainfallTrend Analysis, Standardized Precipitation Index Cite this Article: Mohammed Shahique Sheeraz, Chandra Shekhar Mishra and R.K. Pandey, Trend Analysis of Meteorological Drought Using Standardized Precipitation Index for Allahabad. International Journal of Civil Engineering and Technology, 9(8), 2018, pp. 1458-1465. http://iaeme.com/Home/issue/IJCIET?Volume=9&Issue=8 1. INTRODUCTION The distribution of weather patterns over periods ranging from seasons to several years (below normal) is Climate variability, while any changes in the distribution of weather patterns over periods ranging from decades to millions of years is climate change. As India is http://iaeme.com/Home/journal/IJCIET 1458 [email protected] Trend Analysis of Meteorological Drought Using Standardized Precipitation Index for Allahabad cultivated area under rain fed agriculture hence the climate variability and climate change studies bear crucial important for Indian subcontinent regions [Handbook of Agriculture, 2006]. Therefore in this present study, main important climatic variable i.e. precipitation is focused to study about the relationship between climate variability and hydrology in the study area which could help in the development of sustainable water resources to agricultural sector. It is important to have a basic knowledge of precipitation distribution during individual months, seasons and year for the optimum development of water resources and for planning of agricultural operations over the given region [Wagesho et al., 2012].Any changes in the rainfall pattern may lead to natural calamities like drought and flood conditions. Drought can be categorized as insidious natural hazard that results from lower levels of precipitations than what is considered normal. Whenthis phenomenonextendsfor a longer period of time or over a season, then rainfall is insufficient in meeting the demands of human activities and the environment.A probability based index which is developedfor better representation of abnormal wetness and dryness is the Standardized precipitation index (SPI). SPI can be calculated easily and can be applied conveniently. The only input data required by it is precipitation and the problem of parameter calibration is escaped. But minimum data required for input is 30 years. Thus, it is particularly suitable for drought/flood monitoring. Even though the original purpose of SPI was for drought detection and monitoring, but it can also be applied to identify wetter than normal conditions. 2. STUDY AREA AND DATA USED Allahabad districtwhich is located at 25.45°N latitudeand 81.84°E longitude in the southern part of the Uttar Pradesh at an elevation of 98 meters, stands at the confluence of two, the Ganges and Yamuna.It lies in thesouthern part of Uttar Pradesh state. TheAllahabad district is surrounded in the east by Sant Ravi Das (Bhadohi) andMirzapur districts,Kaushambi district in the west, Jaunpur and Pratapgarhdistricts in the north and Banda district and the state of Madhya Pradesh in the south. Figure 1 Location of Allahabad District The Allahabad district receives an annual rainfall that ranges between 600mm to 1000mm. Precipitation data required for the study of trend analysis covers monthly rainfall data of 51 http://iaeme.com/Home/journal/IJCIET 1459 [email protected] Mohammed Shahique Sheeraz, Chandra Shekhar Mishra and R.K. Pandey years i.e. from 1967 to 2017 for Allahabad district. For present study, the values of Standardized Precipitation Index (SPI) of Allahabad district are estimated with time step of 12 months which are used in the study to show the annual fluctuation of precipitation from its mean as well as abnormal wetness and dryness over study area. The monthly precipitation data for Allahabad district forthe period of 51 years (1967- 2017) is collectedfrom Indian Meteorological Department website(www.imd.gov.in)and Indian Water Portal website (www.indianwaterportal.org). The data is then analyzed for fluctuation of precipitation pattern as well as for measuring severity of abnormal wetness and dryness of precipitation.The software used to calculate SPI is R(version- 3.5.0) 3. METHODOLOGY A probability based index which is developed for better representation of abnormal wetness and dryness is known as Standard precipitation index (SPI) (Mckee, 1993). The current study uses SPI for analysing fluctuation in precipitation pattern as well as for measuring severity of abnormal wetness and dryness of precipitation. In India, SPI is the best tool for monitoring meteorological drought (Jayantasarkar, 2010, Pai 2011). About 60 to 70 % of Indian economy is directly dependent upon agriculture and the agriculture is purely dependent on south west monsoon precipitation.Therefore by use of single parameter i.e. precipitation in order to monitor and analysis of drought, SPI gives better results in comparison to other indices such as percent of normal (PN), Palmer drought severity index (PDSI), Surface water supply index (SWSI) etc. In order to calculate SPI, the difference of the precipitation from the mean for a particular time step and then dividing it by the standard deviation is done. SPI = (1) Where- Xiis the actual precipitation, Xavg is the mean precipitation, is the standard deviation. Mckee(1993), described SPI values range both above and below zero. If the value of SPI exceeds > +2 &< -2 it will be described as being extremely wet and extremely dry respectively. Likewise, SPI values in between +1.99 to +1.50 & -1.99 to -1.50 being severe wet and severe dry respectively, +1.49 to +1.0 & -1.49 to -1.0 being moderately wet and moderately dry respectively and values -0.99 to + 0.99 are near normal. Table 1:SPI Values 2.0+ extremely wet 1.5 to 1.99 very wet 1.0 to 1.49 moderately wet -.99 to .99 near normal -1.0 to -1.49 moderately dry -1.5 to -1.99 severely dry -2 and less extremely dry http://iaeme.com/Home/journal/IJCIET 1460 [email protected] Trend Analysis of Meteorological Drought Using Standardized Precipitation Index for Allahabad 4. RESULT AND DISCUSSION The twelve month SPI analysis for Allahabad district along with annual precipitation (in mm) is shown in table 2. Table 2 Allahabad District SPI Values http://iaeme.com/Home/journal/IJCIET 1461 [email protected] Mohammed Shahique Sheeraz, Chandra Shekhar Mishra and R.K. Pandey For Allahabad, it is clearly found that before 2000, only thirteen severely dry years and one moderately dry year occurred with SPI values ranging from -1.22 to -1.91.However, from 1967 to 2017 there were total twenty-three severely dry years and one moderately dry year with SPI values ranging from -1.22 to -1.91. Overall, the SPI values for Allahabad range from 0.21 to -1.91 for the period 1967-2017 suggesting that there is near normal to severely dry years occurred in Allahabad.From year 2000 to 2017 there are only eight years with near normal precipitation, rest ten years come under severely dry. Scatter Charts for twelve-month SPI analysis of Allahabad district for different time periods(1967-1991, 1992-2017, 1967-1999, 2000-2017, 1967-2017) are given below from figure 2 to figure 6. 0.5 0 1965 1970 1975 1980 1985 1990 1995 -0.5 lues a -1 V I P S -1.5 -2 -2.5 Year 1967-1991 Figure 2 SPI Analysis(1967-1991) 0 1990 1995 2000 2005 2010 2015 2020 -0.5 -1 lues a V I -1.5 P S -2 -2.5 Year 1992-2017 Figure 3 SPI Analysis (1992-2017) 0.5 0 1960 1970 1980 1990 2000 2010 -0.5 lues a -1 V I P S -1.5 -2 -2.5 Year 1967-1999 Figure 4 SPI Analysis (1967-1999) http://iaeme.com/Home/journal/IJCIET 1462 [email protected] Trend Analysis of Meteorological Drought Using Standardized Precipitation Index for Allahabad 0 1995 2000 2005 2010 2015 2020 -0.5 -1 lues a V I -1.5 P S -2 -2.5 Year 2000-2017 Figure 5 SPI Analysis (2000-2017) 0.5 0 1960 1970 1980 1990 2000 2010 2020 -0.5 lues a -1 V I P S -1.5 -2 -2.5 Year 1967-2017 Figure 6 SPI Analysis (1967-2017) The minimum annual precipitation in Allahabad district in past fifty-one years is observed in the year 2009 which was 518.8 mm while the maximum annual precipitation is recorded in the year 1980 which was 1593.7 mm. Scatter chart for annual rainfall for Allahabad district is given in figure 7 (1967-1999) and figure 8 (2000-2017).