Response of Rainfall and Vegetation to ENSO Events during 2001–2011 in Upper Wardha Watershed, Maharashtra, India

Abstract

Understanding the variability of rainfall with El Niño Southern Oscillation (ENSO) events at the watershed level is important for water resource managers to discern the pattern of water available for agricultural planning and water and soil conservation. This study was conducted to determine the responses of rainfall and vegetation to El Niño and La Niña events occurring between 2001 and 2011 in the Upper Wardha watershed in Maharashtra, India. Daily rainfall data pertaining to 14 stations in and around the study area were analyzed in conjunction with 16-day global 250-m Normalized Difference Vegetation Index (NDVI) data from the Moderate Resolution Imaging Spectroradiometer (MODIS) sensor abroad the Terra (EOS AM) and Aqua (EOS PM) satellites. Results indicate correlations between ENSO events, rainfall, and vegetation. Both rainfall and vegetation show a positive anomaly during La Niña events and a negative anomaly during El Niño events, but the effects of all events are not the same. A low volume of rainfall with the early onset of monsoon, multimodal rainfall distribution over time, and intermittent rains are the effects of El Niño on rainfall. The effect of La Niña was to produce wetter conditions in the study area. The impacts of moderate to severe ENSO events (in 2009 and 2010) can be predominantly observed on rainfall and vegetation.