FLOOD IMPACT ON HYDROLOGY, ENVIRONMENT, LIFE AND POLICY (HELP) IN BIHAR

Abstract

Water is needed for various human activities, and therefore, most of the civilisations have developed on the banks of rivers. However, as the density of people increases, the flood plains are encroached for various anthropogenic activities. Presently, India is one of the highly flood prone country in the world. Bihar is one of the important states of India which falls under Ganga river basin and is subject to frequent flooding. The entire North Bihar is crisscrossed by some of the major rivers like Gandak, Kosi, Bagmati, Mahananda etc. meeting the river Ganga on its left bank. All these rivers originate in Nepal and Tibet which meet the river Ganges in the lower reach. In this reach, the velocity of flow reduces, whereas, the spread of water increases causing flooding in large plains of Bihar. Additionally, as the velocity of flow reduces, it causes the problem of siltation. Siltation in various rivers the bed of rivers, thereby, reducing the carrying capacity which in turn has again increased the spread of flood waters covering a larger area under flood. As a result, flooding in such rivers has affected the overall development in flood plains to a great extent. It has affected all spheres of sustainable development like hydrology, environment, life and policy in such areas and has caused adverse impacts over it. Sustainable development means that development which meets the needs of the present without compromising the ability of future generations to meet their own needs. The flooding in rivers has not only affected the needs of the present generation but also affected the ability of the future generation to meet their needs. Sustainability index is a useful tool to reflect the current status of overall development of the region. To ensure sustainability, a comprehensive knowledge of the present conditions of its different indicators and their attributes is necessary. Recurrent flood events affect almost every attribute and hence the different indicators of sustainability index get ~ iii ~ affected. By observing the trend of variation of any indicator and attribute, while planning special attention may be given on identified issues. In the dissertation an attempt has been made to study the impacts of flood on each individual attribute of four indicators of sustainable development in North Bihar. Also, every district and catchment has their own characteristics and hence impacts may be different in different districts. So, work has been extended to analyse the attributes and indicators at district level and at catchment level. Further these indicators have been integrated to determine the sustainability index of region to observe the overall impact of flood during a year within the region. The study also focuses on flood management practices being carried out in the state. Presently more stress has been given on structural measures like embankment construction and maintenance. But to achieve better result in flood management the need of adopting non-structural measures like land-use planning, flood plain zoning, redevelopment of flood-prone areas, flood Insurance, flood forecasting and warning, silt and land management are discussed. Further Water Resources Department, Government of Bihar is the primary agency engaged in flood management. So, its institutional capacity with possible improvements towards its strengthening in order to better flood management is included in the report.