Association of vegetation indices with atmospheric & biological factors using MODIS time series products

Abstract

Natural vegetation is a critical component of ecosystem change models and conservation efforts. Over nineteen years, this study explores the spatiotemporal dynamics of normalized difference vegetation index (NDVI) and enhanced vegetation index (EVI) with atmospheric, biological, and soil indicators, and to determine whether a significant correlation exists between these indices in Bangladesh. We used the Google earth engine (GEE) for geospatial analysis using moderate resolution imaging spectroradiometer (MODIS) datasets to perform the study. Vegetation indices are positively correlated with land surface temperature (LST), Humidity, and Evapotranspiration. From 2000 to 2019, the average increase in vegetation cover (NDVI) was 0.1 to 0.3. LST changes from −6°C to +5°C in numerous places over the previous 19 years (increased in urban areas and mostly decreased in the north-eastern part). Due to increased human activity, LST in the northern part of the country has dropped and increased during the last nineteen years in the center and eastern parts. In the future, new studies on vegetation cover and its relationship to other factors, protection of nature, and resource allocation may benefit from the findings of this study.