Assessment of vulnerability of Indian agriculture to climate change using NDVI variations as indicator – Use of NOAA-AVHRR (8km) & MODIS (250m) Time-Series NDVI Product,

Abstract

Advanced Very High Resolution Radiometer (AVHRR) (8 km) Normalized Differential Vegetation Index (NDVI) data and Moderate Resolution Imaging Spectroradiometer (MODIS) (16-day, 250m) NDVI data products were considered to analyze vulnerability of Indian agriculture to rainfall variability under climate change impact studies. Predicted higher temperature and altered rainfall patterns accompanied by extreme weather events would impact vegetation growth in natural forest, open scrub, agricultural land and plantations. NDVI derived from 2-band information (Red and Near-infra Red) of multi-spectral imagery of AVHRR (1982 to 2006) and from MODIS (2000- 2010) were analysed to understand spatial and temporal variability. Coefficient of Variation (CV) of maximum NDVI from 15-day composites for the total length of the study period was used to assess vulnerability of rain-fed agriculture and results were corroborated with the Standard Precipitation Index (SPI) rather than actual rainfall received during the study period. AVHRR time-series data helped to identify vulnerable areas at regional-scale, i.e., agro-ecological subregions (AESR) due to coarser ground resolution while MODIS data products with 250m pixel resolution helped identify vulnerability at the district level. It was estimated that over 241 Mha areas in the country may not be vulnerable to rainfall variability-induced climate change, whereas over 81.3 Mha in arid, semi-arid and dry sub-humid regions in the country may be vulnerable to extreme weather events. Study indicated that over 12.1 and 1.81 Mha of Kharif cropland would be mildly and severely vulnerable, whereas 6.86 and 0.5 Mha of Rabi cropland may be adversely affected in a similar manner. Of the remaining agricultural lands, 29.93 and 5.24 Mha would also be vulnerable to climate change in a similar manner. Studies also indicated a decrease in length of Kharif and Rabi seasons and a delay in the start of Kharif season based on preliminary findings