Impact of observed climate change on the classification of agroclimatic zones in India

The classification of agroclimatic zones in India was made in the 1990s for identifying priorities and developing strategies for location-specific and need-based research as well as overall agricultural development in the country. Long-term climatic parameters, particularly temperature and rainfall along with soil and crop information were used for the classification of agroclimatic zones. It has been documented with a fair degree of accuracy that overall climate is changing, particularly with respect to temperature over the Indian region. Thus it is anticipated that in the recent past, climate change may be reflected in the agroclimatic zones as well and ultimately affect the criteria of their classification based on climatic parameters. The objective of the present study is to examine the trends and spatial/temporal variability of temperature, rainfall, rainy days, and heavy rainfall in different agroclimatic zones of the country, which may help in better understanding of the further initiatives on reclassification of agroclimatic zones, if required. Using various long-term gridded data from 1985 and instrumental datasets starting from 1951 to 1980, studies have been made to observe changes in different components of the climatic variables, i.e. temperature and rainfall. It has been observed that there are significant changes in temperature and rainfall, both temporally and spatially, across India and there is a definite shift in temperature and rainfall patterns in the recent past compared to 1951-1980. It has also been inferred that there is a need to reconsider the classification of agroclimatic zones in India under the scenario of observed climate changes in the country.