Climate-driven projections of crop water requirements in agro-ecological region II of Gujarat

There is a very sensitive relationship between agriculture and the climate change scenario. This makes the assessment of crop water requirement an essential component under prevailing climate change scenario. This study evaluates the ETc of different crops cultivated across the Agro-Ecological Region II (Western Plain, Kutch, and part of the Kathiawar Peninsula) of Gujarat using the observed climate data (1990-2020) and the downscaled CMIP6 projection for 2021-2050. The bias correction was carried out using the quantile mapping, and the district-wise ETc was estimated using the CROPWAT 8.0. The projected ETc was grouped into three decades and was compared with respect to the baseline data. The percentage change was calculated and analyzed. The result indicates spatial variability within the districts of the AER II region. The results show a location specific variation in ETc of different crops across the different districts of the study area. Most of the kharif crops shows and increase in water requirement indicating and increase in irrigation requirement in the coming decades during the kharif season. Rabi crops exhibit relatively small decline in water requirement suggesting a reduced evaporative demand in the coming decades. Summer crops have a mixed response showing both increase and decrease depending on location. Overall, the findings indicate a location specific effect of climate change on different crops. This emphasizes a need for formulation of location specific adaptation strategies. The study provides a basis for targeted water management planning that contributes to a climate resilient agriculture in the study area.