Investigating spatial and temporal dynamics of the Teesta River behavior in the northern landscape of Rangpur, Bangladesh
摘要
The Teesta River is a major transboundary river in northern Bangladesh, yet its morphology and hydrological regime have undergone substantial changes due to climatic variability and human interventions. This study analyzes spatial and temporal dynamics of the Teesta River in Rangpur district from 1990 to 2023 using Landsat imagery, GIS-based channel migration analysis, and hydro-meteorological data. River migration averaged 0.77 km during 1993–2003, decreased to 0.45 km during 2003–2011, and slightly increased to 0.57 km during 2011–2023. Total river area declined markedly, particularly during late winter, from 35.93 km2 in the early 1990s to 11.04 km2 in 2023. Pre-winter erosion dominated river dynamics, whereas late-winter accretion increased from 7.79 km2 (1992–2001) to 15.67 km2 (2011–2023). Water levels at Kaunia station show a consistent decline, with minimum levels dropping from 27.65 m in 1990 to 25.68 m in 2023. Late-winter rainfall (March–April) decreased sharply from 150–180 mm in 1990 to below 20 mm in 2023, while groundwater depth increased from 2.26 m to 3.95 m over the same period over the same period. The results demonstrate a progressive degradation of river health during the dry season, driven by reduced rainfall, groundwater depletion, and upstream flow regulation, underscoring the need for integrated river and groundwater management.