Seasonal Flow Variability and Stage Dynamics of the Teesta River: Insights from 29 Years of Multi-Station Data

Abstract

This study examines the long-term seasonal flow variability and water level of the Teesta River between 1995 and 2023 across four main stations (Kaunia, Dalia, Doani, and Haripur), supporting a population of 11.5 million and approximately 14% of the agricultural land in Bangladesh. The results indicate that the maximum discharge has significantly decreased from 8577 m3/s in 2004 to 1629 m3/s in 2013 at Kaunia station. Additionally, the annual minimum discharge dropped to 1.47 m3/s in 2012. Conversely, the water levels showed a rising pattern with the highest point at 30.23 mMSL at Kaunia and 52.91 mMSL at Dalia. The mean maximum and minimum discharges at Kaunia were 3171.75 m3/s and 28.35 m3/s respectively, indicating high intra-annual variability. The findings also indicate a decoupling of discharge and water level trends, indicating a decrease in channel conveyance capacity as a result of sedimentation and channel aggradation. These results reveal critical changes in the river dynamics and the need for combined transboundary water management and adaptive sediment control actions to secure long-term water security in the Teesta basin.

The Dhaka University Journal of Earth and Environmental Sciences, Vol. 15(1), 2026, P 47-62