TN-92 : Effect of urbanization on runoff

Abstract

Urbanization which may be broadly defined as the process* of expanding urban influence, has been taking place for more than 6000 years, its pace has increased markedly since the beginning of the nineteenth century. With this the demand for water also increased. The role of water as a nuisance became more immediate concern to individual, which are, flooding drainage, erosion and sedimentation. This paved the way for study of urban hydrology as a separate consideration within general field of hydrology.

The important highlight of 1981 census in India is the unprecedented rapid growth of urban population. It is estimated that by the end of this century the urban population in the country will be more than 300 million. At this pace, the urban runoff will also increase tremendously. As we know that at present in India the practice of urban storm runoff measurement is with the help of empirical formula which is not adequate for design of a complex drainage system. Instead more emphasis should be given to implement the findings of recent researches and models developed by various countries of the world.

In this technical report an attempt is made to review the existing urban drainage models and the researches carried out by the scientists of the country and abroad on the effect of urbanization on runoff.