Use of NDVI to Assess Variability in Length of Crop Growing Period inducing Agricultural Vulnerability: a study of Telangana Region in Peninsular India

Abstract

The satellite data-based Normalized Difference Vegetation Index (NDVI) was used to assess the state of agriculture and crop vigour on a temporal basis to study agricultural vulnerability to climate change on a regional scale in a semi-arid red and black mixed soil region in Telangana, in the southern part of the Indian peninsula often referred to as the Deccan Plateau extend across 11.48 million hectares (mha) with 6.98 mha under rainfed agriculture. It provides a source of livelihood for 3.3 million farmers with small land holdings and 4.3 million farm labour and their dependants. The annual rainfall ranges from 600-1100 mm, of which 71% is received during the southwest monsoon period. Rainfed agriculture is the major land-use activity and increased climatic variability in recent decades has resulted in frequent losses, forcing governments to find suitable solutions. In order to understand factors that contribute to increasing agricultural variability in Telangana, and to understand trends in climatic variability and extreme weather events and their impact on agricultural production, time-series AVHRR NDVI data products were analysed and corroborated with the Standard Precipitation Index (SPI). The length of crop-growing period (LGP) was estimated from NDVI and studied as a Sensitivity Indicator for agricultural vulnerability, as it indicates crop health and vigour, which determine agricultural yield.