Table 2 Various rainfall indices and their definition
Rainfall Index | Definition | Unit | Remarks |
|---|---|---|---|
For rainfall shortage effect: extracted using local rainfall | |||
Seasonal local rainfall (SLR) | Total amount of rainfall during monsoon season (May to October) | mm | |
Number of dry days (NDD) | Number of days with daily rainfall < 2.5 mm during monsoon season (May to October) | day | Vinnarasi and Dhanya (2016) |
Maximum consecutive dry days (CDD) | Maximum number of consecutive dry days during monsoon season (May to October). The dry day is defined as the day with rainfall < 2.5 mm | day | |
Maximum consecutive wet days (CWD) | Maximum number of consecutive wet days during monsoon season (May to October). The wet day is defined as the day with rainfall ≥ 2.5 mm | day | |
For flooding effect: extracted using basin average rainfall | |||
Seasonal Basin average rainfall (SBR) | Total amount of basin average rainfall during crop growing period (July to October) | mm | |
Number of heavy rainfall days (HRD) | Number of days with daily basin average rainfall ≥ 20 mm during crop growing period (July to October) | day | |
5-day maximum rainfall (5DR) | Maximum 5-day basin average rainfall (during July to October) | mm | |