Abstract

Abstract
The main problems faced during the monsoon in the country are flooding, drainage, congestion and bank erosion. A relatively high flow or stage in a river, marked by higher than the usual, causing inundation of low land or a body of water, rising, swelling and overflowing land not usually covered is termed as flood. The flood plains are the playground of the river and should be left as such without any human interference. Wise as it may seem, this philosophy can not be practical basis for flood management in the developing countries like south Asia, South East Asian countries and China, firstly, the limits of these play grounds are difficult to define. For alluvial rivers, when the land topography has often been created by river itself, the rivers are the meandering or braided form. The alluvial rivers that cut and decide their own shapes normally have a water way related to their nominal discharge. Very roughly, the width of these “playground” would be for to six times such a waterway width for the meandering rivers and even larger for the braided rivers. As a result a very large part of the Gangetic alluvial would have to be left alone without human settlements. This is clearly not practicable and pragmatic approach of a management. This pushes the need for flood hazard mapping and joining flood hazard mapping and joining techniques one their origin and development to the pioneering works of several individuals and organizations including Ellies 1969, Sheoffer, 1964, U.S. Army Crop of Engineers, 1973, Sheoffer Ellies and Speecker 1970, Weolman 1971 and Dingonar 1975. In their classic studied, head shown a new horizon for flood plain mapping in urban areas. Several environmentalists like Hack and Goodlett 1960, Sigafors 1964 and Rechardson 1968 have also devised alternative processors for flood hazard mapping.

India being the second largest flood prone country in the world, the need for flood inundation as well as socio-economic zones in flood prone areas in most essential for the country’s economic development and environmental management. After the unprecedented flood of 1954, the government of India took several initiatives and constituted a number of committees to study the problem of land in the floods. The some important initiatives are policy statement 1954, high level committee on floods 1957, policy statement of 1958 Ministerial Committee on flood control 1964, Ministers Committee on floods and flood relief 1972, Working groups on flood control for five years plan, Rashtriya Barh Ayog 1980, National Water policy 1987, National commission for integrated water resources development plan 1996. Historical flood damage data 1953-2000 brings out the fact that during this period the area effected by floods remained more or less constant, whereas the population effected and crop damage are showing an increasing trend.

There is a general perception that in spite of spending large amount of money for various flood management works in the country the flood damage is increasing. Further, the shape of research in this area of vital human concern is rather slow in the country. In this regard mention may be made of the work of Kayastha and Yadava 1977 Chakraborty 1979, 1991, Goswami 1991 and Rango and Enderson 1994. The use of remote sensing techniques particularly those that are satellite based has significantly improved the quality and coverage of flood mapping in the country in recent years. Large scale investment in flood protection, huge recurring damages, gradual and steady increase of population pressure on land forces demand for objective flood plain zoning considering the constraints and aspiration of land users on one hand and flood disaster on the other hand. In this study an attempt has been made to develop an analytical object oriented model in GIS for flood plain zoning. Inputs to the model were extracted from synergistic use of remote sensing data and conventional data. It is expected that model may be used for utilization of flood plains in such a manner so as to reduce the flood damage and disaster.