Vegetation dynamics and its driving factors in agro-climatic zones of Upper Bhima Sub-basin, Western India

Abstract

Climate change is a key threat to biodiversity and ecosystems. The impacts of climate change on vegetation must be evaluated to control the sustainability of the ecosystem. Precipitation and temperature are the most important climatic parameters affecting vegetation growth. It is important to analyze the spatial and temporal variations of vegetation under changing climatic parameters to envisage the response to the regional ecosystem. In this study, variation of the Normalized Difference Vegetation Index over five different agro-climatic zones in the Upper Bhima Sub-basin from 2003 to 2013 was analyzed to find the effect of climatic and hydrological variables on vegetation dynamics. The correlation analysis has been performed by using the Pearson correlation method and Geographical Detector Model. Taylor diagrams are generated to highlight the variation in the correlation values of NDVI with other variables. Results show that precipitation and temperature are key parameters for the growth of the vegetation, but Western Ghat Zone shows contradictory results. To identify the reasons behind contradictory results in the Western Ghat Zone, hydrological parameters such as soil moisture, terrestrial water storage and groundwater levels are analyzed. NDVI shows a positive correlation with precipitation in Water Scarcity Zone, and Assured Rainfall Zone with correlation values 0.37, and 0.462 respectively, but, in the Western Ghat Zone, NDVI has a negative correlation (− 0.38) though more than average precipitation occurs in that region. The result of the Geographical Detector Model reveals that the terrestrial water storage and precipitation are dominant factors affecting vegetation in WGZ and WSZ, respectively.