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Water Logging in Bangladesh

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Water Logging in Bangladesh
STORM WATER DRAINAGE MODEL COUPLED WITH FLOOD DEPTH MAPPING: A NEW APPROACH TOWARDS SOLUTION OF URBAN DRAINAGE PROBLEMS
Mir Mostafa Kamal* and M Fazle Rabbi** * River Hydraulics Division, Surface Water Modelling Centre, Dhaka-1206, Bangladesh ** Water Resources Division, Surface Water Modelling Centre, Dhaka-1206, Bangladesh ABSTRACT
Storm water drainage and its management in many large cities in the world are becoming increasingly problematic. Unplanned or poorly planned urban development along with man made intervention in the natural drainage systems are compounding the fact. With the advent of very fast computing facilities, sophisticated mathematical modelling tools have come forward to solve urban drainage problems. A study was carried out for the Central part of Dhaka, the capital of Bangladesh, regarding the severe waterlogging problem recurring every time due to even a moderate rainstorm. An urban drainage modelling software, MOUSE of the Danish Hydraulic Institute (DHI) of Denmark was used in conjunction with Geographic Information System (GIS). Model based waterlogging maps (flooding depth and extent map) produced for September and October 1996 rain showed close matches to the real situation. Graphical two-dimensional animation of waterlogging and its improvement under several alleviation schemes were of practical help in visualising the real situation. The study results suggest that a meaningful solution for urban drainage problems can be obtained with better confidence of optimisation using the coupled use of an urban drainage model and flood depth mapping.

KEYWORDS Storm water; Dhaka City; Mathematical Model; Sustainable Management INTRODUCTION Background Storm water drainage and its management in many large cities in the world are becoming increasingly problematic. Unplanned or poorly planned urban development along with man made intervention in the natural drainage systems are compounding the fact. With the advent of very fast computing



References: Chow V. T, Maidment D. R. and Mays L. W. (1988). Applied Hydrology, International Edition, McGraw-Hill Book Company, New York. DHI (1995). Technical Reference Manual of MOUSE, Danish Hydraulic Institute, Hoersholm, DK-2970, Denmark. JICA (1987). Study on Storm Water Drainage System Improvement Project in Dhaka City. Japan International Cooperation Agency, Dhaka Water Supply and Sewerage Authority, Dhaka, Bangladesh. JICA (1990). Updating Study on Storm Water Drainage System Improvement Project in Dhaka City, Japan International Cooperation Agency, Dhaka Water Supply and Sewerage Authority, Dhaka, Bangladesh. Mot MacDonald (1993). Tertiary Drainage in the RAJUK Area, Dhaka Metropolitan Development Programme, Dhaka, Bangladesh. SWMC (1997). Storm Water Drainage Modelling for Dhaka City: A Pilot Study. Surface Water Modelling Centre, Dhaka-1206, Bangladesh.

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