Assessment of Meteorological Drought Using Standardized Precipitation Evapotranspiration Index—Hyderabad Case Study

Abstract

AbstractDroughts are recognized as a natural disaster that is caused by the extreme and continuous shortage of precipitation. Drought indices assist in a number of tasks, including their early warning and monitoring by computing severity levels and proclaiming the start and end of droughts. Various drought indices were formulated for the forecasting and prediction of spatiotemporal drought characteristics using various hydrological variables, such as precipitation, evapotranspiration, runoff and soil moisture content. Due to anthropogenic global warming and the increase of temperature, evapotranspiration-based drought indices have become an interest in recent years in drought assessment. This paper attempts to provide more information on drought indices which incorporates Evapotranspiration. The study used Standardized Precipitation Evapotranspiration Index (SPEI), based on evapotranspiration to understand the drought variability at various time scales. This study adopted the Hargreaves model to calculate Potential Evapotranspiration. The SPEI index can also be used to study the wet and dry periods including Evapotranspiration along with precipitation. The study used SPEI to understand the dry and wet years over an urban semi-arid region, Hyderabad, capital and the biggest city of the southern Indian state of Telangana for the years 1965–2015. The years 1965, 1966, 1972, 1973, 1985, 1993 and 2012 were noted as dry years with SPEI values −1.35, −1.06, −1.43, −1.31, −1.05, −1.22 and −1.51 sequentially and year 2006 as the severe wet year with an SPEI value +1.65. The characterization of dry and wet years as demonstrated in the present study will enhance better urban water resources management.KeywordsDroughtSPEIEvapotranspirationHyderabad