Large parts of Maharashtra are reeling under drought, aspects of which are being reported in the ‘Dry Wave’ series of this newspaper. While the word ‘drought’ usually brings to mind a period of unusually dry weather, crop damage and water supply shortages, there are guidelines in place for a state government for declaring a drought in a state or area. A manual published by the Ministry of Agriculture in 2016 suggests a three-step approach.
The first step is to look at two mandatory indicators — rainfall deviation and dry spell. Depending on the extent of deviation, and whether or not there is a dry spell, the manual specifies various situations that may or may not be considered a drought trigger.
The next step is to look at four impact indicators — agriculture, vegetation indices based on remote sensing, soil moisture, and hydrology. Each impact can be assessed on the basis of various indices. “The States may consider any three of the four types of the Impact Indicators (one from each) for assessment of drought, the intensity of the calamity and make a judgement,” the manual states. If all three chosen indicators are in the ‘severe’ category, it amounts to severe drought; and if two of the three chosen impact indicators are in the ‘moderate’ or ‘severe’ class, it amounts to moderate drought.
The third step comes in after both previous triggers have been set off. In that event, “States will conduct sample survey for ground truthing… in order to make a final determination of drought. The finding of field verification exercise will be the final basis for judging the intensity of drought as ‘severe’ or ‘moderate’.”
Once a drought is determined, the state government needs to issue a notification specifying the geographical extent. The notification is valid for six months, unless de-notified earlier.