Assessment of the responses of spatiotemporal vegetation changes to climatic variability in Bangladesh

Understanding the effects of vegetative land cover in Bangladesh on climatic variability and dynamics is still a critical issue for environmental sustainability as well as global and regional climate policy formulation. This study aimed to gain a better understanding of the responses of vegetation changes and built-up area changes to climatic variability in Bangladesh during 1990-2020. Based on the Normalized Difference Vegetation Index (NDVI) dataset, we analyzed the spatiotemporal characteristics of vegetation dynamics and the proportion of urban land changes across all the urban and rural areas of Bangladesh and investigated the relationships between the variability of temperature, precipitation, and humidity through Pearson's correlation (PC) and geographically weighted regression (GWR) models. This study found complex variations in growingseason NDVI and climatic factors across the country. The results indicate a declination of vegetation areas and precipitation, with an increase in built-up areas (12.60% in urban and 11.68% in rural areas), temperature, and humidity. The correlation between growing-season NDVI and climatic factors demonstrates a strong inverse influence of temperature up to - 0.78; and positive influences of rainfall up to + 0.51 and humidity up to + 0.06, but in the case of built-up area changes, temperature change is positively correlated, while rainfall and humidity are negatively correlated to built-up expansion. Findings suggest that climatic factors are more responsive to built-up land expansion than vegetation dynamics in the urban and rural areas of Bangladesh. The unplanned development activities would persist and continue to affect the environment and sustainability. This study provides policymakers and the Bangladesh government with critical information on environmental development and sustainability improvements that will lead to the long-term sustainability of natural resources and environmental health.

Automated summary

This study aimed to understand the responses of vegetation and built-up area changes to climatic variability in Bangladesh. The study found a decline in vegetation area and precipitation, and an increase in built-up areas, temperature, and humidity. Climatic factors are more responsive to built-up land expansion than vegetation dynamics.