Symbolic representation of district wise climate change scenarios of West Bengal state, India, using Thornthwaite classification scheme

Abstract Now-a-days, multi-level stakeholders starting from grass-root level farming community to Government level policy makers need to have adequate climate change information before hand to implement appropriate adaptation and mitigation strategies towards combating climate change at local scale. However, availability of climate change data is not adequate at district and block level. The present study has attempted to reveal how the district level climate has changed in last 120 years over 23 districts of West Bengal in India using Thornthwaite classification scheme (TCS). The change of climate from moist to dry or vice-versa from mean climatological period of 1901–1930 to 1991–2020 has been assessed and represented through four different English letters based on the calculated values of TCS. The study of many indicators showed that symbolic representations remain same in some districts but in several districts these vary according to changes of time period. The B 1 A'a'w 2 symbol was used to express climatic type of PurbaBardhaman during the first three climatological eras, but it was altered to C 2 A'a'w 2 for the last period, showing a shift in moisture index (I m ) value. This reveals how the climatic type is continuously changing in North Bengal and South Bengal districts of West Bengal through the passage of time. Furthermore, it has been noted that while the majority of North Bengal districts have changed to drier conditions as their I m value has decreased recently, several South Bengal districts indicate moist conditions compared to the previous climatological periods with increases in moisture index (I m ) value.