Prof. Sudip Basack
Department of Civil Engineering, Graphic Era Deemed to be University, Clement City, Dehradun, Uttarakhand, India
Title: Integrated Rainfall Trend Analysis and Hydrodynamic Flood Assessment: A Case Study in Eastern India
Abstract:
Rainfall variability
and flood hydraulics are critical concerns for riverine regions influenced by
both hydroclimatic change and local hydraulic controls. This study integrates
long-term rainfall trend analysis with one-dimensional hydrodynamic modelling
to assess hydroclimatic variability and flood susceptibility along the Ganga
River near Farakka Barrage, West Bengal, India. Daily gridded rainfall data for
1991–2025 were analysed using the Mann–Kendall test, Sen’s slope estimator,
Bias-Corrected Pre-Whitening, Trend-Free Pre-Whitening, modified Mann–Kendall
approaches, Pettitt’s test, and sequential Mann–Kendall analysis. The rainfall
analysis indicated an overall decreasing tendency, although statistical
significance varied among the applied tests and was mainly supported by
modified Mann–Kendall results after accounting for serial correlation.
Pettitt’s test suggested statistically weak change points around 2020–2021,
while sequential Mann–Kendall analysis indicated a possible recent shift around
2023. Hydrodynamic simulations were performed using HEC-RAS 6.3 for 25-, 50-,
and 100-year design-flood scenarios to evaluate water surface elevation,
velocity, discharge, and inundation behaviour. The results showed increasing
hydraulic severity with longer return periods, with higher water levels,
velocities, discharge magnitudes, and flood depths. The Farakka–Nimtita reach,
particularly near Dhuliyan, Arjunpur, and Nimtita, emerged as a vulnerable
corridor due to channel irregularity, high flow concentration, floodplain
exposure, and potential bank erosion. The integrated approach provides a
practical basis for flood-risk assessment, embankment inspection, floodplain
zoning, and early-warning planning in the selected Ganga River reach.
Keywords: Rainfall Trend
Analysis, Hydrodynamic Modelling, HEC-RAS, Risk Assessment
Biography:
Prof. Sudip Basack, Ph.D., FIE, C.Eng.,
M.ASCE, is a civil engineering professional with extensive academic and
research experience in India and abroad. He has published more than 150
technical papers in reputed journals and conferences and has received several
national and international research awards. He actively reviews for leading
international journals and has supervised postgraduate and doctoral
researchers. His academic contributions include sponsored research projects,
invited lectures, and academic visits to countries including the USA, UK, Germany,
Australia, New Zealand, Singapore, and China.
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Coauthor and Co-presenter:
Ghritartha Goswami, Ph.D., M.Tech.,
B.E., C.Eng., AMIE, Aff.M.ASCE, LM.IWRS, is a Hydro Informatics Engineer with
the Water Resources Department, Government of Assam. He holds degrees in civil
engineering and water resources engineering. His work focuses on hydraulic
modelling, water availability, climate change impacts on river basins, and
saline water intrusion. He has also served in various academic roles and has
contributed through publications, conference participation, professional
memberships, awards, and leadership activities.