ASSESSING THE EVAPOTRANSPIRATION OVER DIFFERENT STATES OF NORTH-EAST INDIA USING SATELLITE-BASED DATA

Abstract

Evapotranspiration (ET) plays a crucial role in the hydrological cycle and shifts in its pattern can
directly influence the availability and distribution of water resources within the concerned region. The contribution
of ET varies from place to place, reflecting land cover heterogeneity. As such, the present study analyses climate
change and its effects on the hydrological cycle through investigating the variation of water budget-derived ET
in different states of North-East India (NEI). The MODIS satellite retrieved ET dynamics exhibits an increasing
trend at a rate of 3.28 mm/year over NEI during 2000-2021. The highest ET (>1000 mm/year) is observed in the
states with more forest cover: Manipur, Mizoram, Nagaland and Tripura while, Arunachal Pradesh exhibits the
lowest ET (698 - 812 mm/year) because some of its mountains are covered with snow and owing to its latitudinal
positions. Trend analysis exhibits a significant rise in annual ET across Assam (4.26 mm/year), Manipur (3.58
mm/year), Meghalaya (3.71 mm/year), Mizoram (5.36 mm/year), Nagaland (3.58 mm/year) while in Arunachal
(1.37 mm/year) and Tripura (5.06 mm/year) the observed trends are insignificant, which are evaluated by Mann-
Kendall Test. The analysis reveals that the highest ET occurs in monsoon season in all the states and lowest in
the winter season. Most of deciduous plants reached its maximal growth during high ET season that coincided
with highest amount of rainfall and sufficient soil moisture. This study highlights the importance of considering
vegetation and geographical position in analyzing ET.