A composite system of drought monitoring under Integrated Agromet Advisory Service

摘要

Agricultural drought impacts vary greatly since they depend not only on the magnitude, timing, duration and frequency of rainfall deficits but also on the differing responses of various soils, plants and animals to water stress. IMD monitors agricultural drought on a real-time basis during the main crop seasons (kharif and rabi) of India. For this, an aridity anomaly index (AI) developed on the lines of Thornthwaite's concept is used to monitor the incidence, spread, intensification and recession ofdrought. Bi-weekly aridity anomaly reports are prepared for the country during the monsoon season. There is a need for improved drought monitoring, as it is the most costly disaster. A composite system of drought monitoring is envisaged by combining a number of indices like SPI, Dryness Index, WRSI and % departure of rainfall at national level. Using the proposed system, a case study has been taken for North Interior Karnataka (NIK). The study indicates that severe drought conditions occurred in Bijapurand Gadag during 24-29 standard weeks compared to other districts of NIK.