Climate change impacts on subsistence paddy farming in Indian East Coast: A Geospatial and Community Perception Assessment

Abstract

Impact of climate change on subsistence agriculture is a major concern in the developing world. The vulnerability of the coastal regions to climate change has been highlighted in particular. The present study assessed the impact of climate change on subsistence rice farming in Eastern Indian coast using an integrated approach of statistical trend analysis by Mann Kendall’s Test and Sen’s Slope Estimation of climate data, remote sense-based land cover analyses using Normalized Difference Vegetation Index (NDVI), Normalized Difference Water Index (NDWI) and Land Surface Temperature (LST) complemented by questionnaire-based perception survey among the farming community. There has been noticeable change in both ambient temperature and LST in the region. Delayed arrival of monsoon critically impacts the cropping calendar. The crop harvest season has shifted further into a time of the year that is prone to weather extremes. Analyses of NDVI and NDWI also indicate shift in cropping calendar. Over years, there was increasing degree of negative correlation between LST and NDVI in November which indicates increasing water stress for crops in that time juncture. This may further cause crop sterility and yield loss. The study also reveals large scale conversion of paddy growing agricultural land into prawn aquaculture ponds. Farmers attributed such landuse change to cultivation stress caused by delayed monsoon and consequent crop loss from weather extremes and changes in crop agronomic conditions. Farmers also report increased pest attack and attribute that to increasing temperature regime.