Exploring the dynamic relationship between enhanced vegetation index and meteorological variables in Pakistan

Abstract

Vegetation is an important component of the earth’s ecosystem and contributes to regulating the climate, carbon sequestration, water cycle, energy transfer, wind movement, and soil development. This study examines the Enhanced Vegetation Index (EVI)and its association with other meteorological variables,  such as precipitation, Relative Humidity (RH), Wind Speed (WS), and Soil Moisture Content (SMC) on Pakistan over two decades  (2002 to 2023). Satellite data sets of MODIS-Aqua, MERRA-2, AIRS, and TRMM were utilized in order to do so. The correlation, seasonal, and averaged maps were prepared and analyzed to understand the relationship of all variables. The results indicate that the maximum EVI (0.398) was observed in the north, east, and along the Indus and its tributaries. However, the minimum EVI (-0.112) was detected in the mountainous north and western parts of Balochistan. The seasonal maps revealed a high distribution of precipitation (0.15 mm/month) in the north while the minimum precipitation (0.005 mm/month) was reported in the south during summer. RH (77.87%) in the north and east while minimum RH (11.19%) in the west. The maximum WS (9.11 m/s-¹) was found in the western and southern half. Additionally, the lowest WS (1.79 m/s-¹) was found in the mountainous north SMC (0.33kgm-2), from March to May in the north and northeast. The minimum SMC (0.03kgm-2) was detected in the western and southern parts of Pakistan. Furthermore, a positive correlation between EVI and all meteorological variables and SMC was found. As Pakistan encounters diverse challenges such as climate change and rapid population growth, EVI-based assessment will play a pivotal role in assessing land use changes, sustainable growth, and resilient ecosystems.