Major heat waves are occurring over India during the hottest months of May and June. Since the temperature extremes have major impact on human health and agriculture, better understanding the dynamics behind its evolution and propagation will help us to develop effective mitigation strategies. Understanding the spatio-temporal distribution, evolution and dynamics associated with heat waves is lacking over this region, due to the lack of high-resolution weather information. Here, we developed a high-resolution (4 × 4 km) dynamically downscaled hourly climate data for April to June during period of 2001-2016. The downscaled daily surface temperature is in good agreement with station observations, which is also in agreement with the observed features of temperature distribution during this period. Based on the Indian meteorological department definition, intensity of the heat waves is identified and re-classified into minor and severe category. The spatio-temporal distribution of each heat wave shows variation in its spatial coverage and also in its intensity. The distributions of heat waves are mainly over central India, North-West India and states such as Odisha, Andhra Pradesh and Telangana during pre-monsoon season. Results show that the increase in meridional heat transport is higher than the zonal advection component, and intensification of heat waves is linked with heat accumulation over a particular region associated with weakening of heat transport. The further amplification associated with depletion of soil moisture will result in the reduction in evaporative cooling, and it will further amplify the surface air temperature.

Paddy is the important, food grain, cereal crop, and staple food crop of India. India ranks second in production of paddy after China. This establishes the pressing need for the study of vulnerability and trend of paddy cultivation and productivity in India. Andhra Pradesh being one of the largest producers of paddy, the compound growth rate and instability in area, productivity and production of paddy in Andhra Pradesh was assessed after the remainder of the state of undivided Andhra Pradesh after bifurcation in 2014 with the jurisdiction of four Rayalaseema and nine Coastal Andhra districts. In this study, we have analyzed the trend & carried out instability index analysis in paddy crop area, productivity and production across district of Andhra Pradesh to explicate the trend in extent paddy cultivation and paddy productivity, district wise Cuddy-Della Valle-Instability Index (%) for the paddy cultivating area from 1991-92 to 2018-19, using the data collected from Directorate of Economics and Statistics, Andhra Pradesh. We assessed district wise Cuddy-Della Valle-Instability Index (%) in paddy productivity from 1991-92 to 2018-19 and found that in Andhra Pradesh, the area of paddy cultivation, paddy productivity output has changed in the study area over the time. Between 1991-92 and 2018-19, the overall paddy growth rate of the area showed a decline of 0.5%. And growth rate of paddy productivity was 1.31% while the increase of production was 0.74%, which can be attributed to the negative impacts arising out of changing weather patterns.