CONSTRUCTION OF SHELTER FRIENDLY EMBANKMENT TO SAVE FLOOD AFFECTED PEOPLE FOR LONG TIME FLOOD MANAGEMENT
Coastal and river flood embankments are used to protect people, property and the environment from high flood and storm water levels. They are the principal type of infrastructure (asset) used by local people and their effective performance during flood events is critical for the provision of sustainable flood risk management. The assessment of existing flood embankments, the design of improvements, and the specification of management action all needs to be done in a manner that takes account of good practice and utilizes appropriate specialist skills.It is a well-known fact that Bangladesh is a highly flood-prone country. As the result of annual floods, significant number of houses in the countryside as well as in urban areas is being destroyed annually. In recent floods during year 2007 we have seen a total or partial destruction to significant number of rural houses making about 5 million people homeless. To a large extent, the patterns and causes of destruction seem to result from poor technical knowledge and wrong perceptions. There is no adequate support for housing projects for low-income, flood-vulnerable communities through development projects undertaken by NGOs and the government, and dwelling houses in rural areas and urban slums are mostly owner-built without proper technical guidance. Construction of earthen embankments for flood control, irrigation and drainage have been the history of Bangladesh but these can't solve the flood problem, effectively and permanently because of their ease of vulnerability with rain splash and flow of flood water. Construction of earthen flood control embankments is an established practice in Bangladesh for protecting people's lives and homes, agriculture and infrastructures. The paper reports the options for multipurpose use of embankments in Bangladesh based on the field visits to embankments site, collected data and information on failure and on-service embankments during field visits, necessary data related to embankments construction practice obtained from available publications and news paper information reported in the year 2007. It studies the basic features and characteristics of floods and flood hazards, and reviews the design & construction practices followed. Several cases of successful and unsuccessful river and flood control embankments are investigated and analyzed. Based on the results of analyses and discussion, it shows that the present method of embankments in Bangladesh, although requires huge amount of money for its construction and repair every year, fails to solve the flood problem effectively and permanently rather it brings many other new problems. It not only increases the siltation on the floodplains and river beds but also creates a risky situation for the inhabitants inside the boundary of embankments. On the basis of overall present situation in Bangladesh, the paper also suggests a proper design and construction method of embankments to control and minimize the extent of flood hazards in the long run and also concluded that to achieve consistent standards of management of flood embankments, and also to raise these standards to optimize their performance, require (a) better understanding and application of good practice, and (b) a range of research actions.