Assessment of meteorological drought in western central table land agro-climatic zone of Odisha, India

Abstract

In this paper, assessment of meteorological drought has been carried out by standardized precipitation index (SPI) for Western Central Table Land Agro-climatic Zone covering six districts of Odisha, India. Monthly rainfall data of 115 years (1901-2015) for all the six districts of this agro-climatic zone of Odisha were analyzed using SPI on different time scales of 1, 3, 6, 9, and 12-month. Results indicate that mild drought events have the highest frequencies of occurrence followed by moderate drought events for all timescales under analysis in all the districts. The average total frequency of drought of all intensities are observed to be 54.10% out of which mild, moderate, severe and extreme drought will occur with frequencies of 35.5, 9.5, 6.25 and 2.85%, respectively. 49.25% areas of this agro-climatic zone in the state are affected by drought of various intensities out of which the share of mild, moderate, severe and extreme drought is 28.40, 13.28, 5.05 and 2.52%, respectively. Keywords: Agro-climatic zone, meteorological drought, standardized precipitation index, western central table land zone Introduction Drought is a natural hazard which is caused due to low precipitation than the normal. Its extent over a longer period of time affects human activities and the environment. Its occurrence is uncertain and it cannot be visualized. Difficulty in accurate prediction of its onset and uncertainty about its spread and severity render this phenomenon more harmful. Therefore, the study of drought and preparation of contingency plan based on its characteristics is very important for mankind in general and for government in particular (Dash et al. 2013; Panigrahi and Panda 2001) [7, 17]. Identification and classification of drought severity are some of the most difficult aspects of drought management. Drought indices are used to monitor and assess severity of drought for effective crop and water resources planning. They are helpful to study the impact of climate change and its variability and various anomalies study related to climate change (Wilhite et al. 2000; Tsakiris et al. 2007) [23, 20]. Moreover, drought indices are helpful to identify and locate places suffering from deficit of available water resources which may affect the effective use of crop production and productivity (Tsakiris et al. 2007) [20]. A number of researchers have studied on identification and quantification of drought indices. Most of these drought indices are based either on meteorological or hydrological variables. As reported by Buttafuoco et al. (2015) [3] some important indices include the Surface Water Supply Index (SWSI; Shafer and Dezman 1982) [19] , the National Rainfall Index (RI; Gommes and Petrassi 1994) [10] and the Standardized Precipitation Index (SPI; McKee et al. 1993) [14]. Vicente-Serrano et al. (2010) [22] proposed the Standardized Precipitation Evapotranspiration Index (SPEI) which is based on precipitation and temperature data Gocic and Trajkovic (2014) [9] analysed monthly precipitation data from 29 synoptic stations using a number of different multivariate statistical analysis methods to investigate the spatial variability and temporal patterns of precipitation across Serbia. They identified three distinct sub-regions by applying the agglomerative hierarchical cluster analysis to the two component scores.