Impact of Forest Dynamics on Slope, Chlorophyll Indices, and Other Biophysical Parameters over Lower Ganga Plain

Forests store half of the world’s terrestrial carbon, which regulates the biosphere and climate. However, industrialisation and mining have disrupted forest productivity. This study examines changes in high-density vegetation (HDV) over five years (2019-2023) in the IndoGangetic plain (Sahibganj, Jharkhand) using NDVI indices. The study focuses on the relationship between chlorophyll and vegetation indices in forests with slopes $\geq$ and ${\lt}15^{\circ}$. Results show a significant decline in HDV from $140.97 \mathrm{~km}^{2}$ to 133.86 $\mathrm{km}^{2}$. The correlation between MCARI and NDVI, and $\mathrm{CI}_{\mathrm{RE}}$ and NDVI, was highest on steeper slopes, with the ordinary least squares (OLS) regression model performing best for slopes $\geq 15^{\circ}$ (R of 0.81 and 0.80 for $\mathrm{CI}_{\mathrm{RE}}$ and MCARI, respectively). These findings highlight the potential of $\mathrm{CI}_{\mathrm{RE}}$ and MCARI for estimating chlorophyll content in higher terrain.