Determination of Surface Drainage Coefficients for Thane District

The drainage coefficient for any region varies with the geographical location, land use, size of area, rainfall intensity, frequency and duration and other climatic factors. Rainfall is the most important factor influencing the value of drainage coefficient and large number of rainfall data is required for its depth duration frequency analysis. Removal of free water promotes the soil bacterial action essential for manufacture of plant food by allowing air to enter the soil and consequently improving crop production Plant roots. The economic benefits of drainage are typically portrayed by an increased yield coupled with reduced production costs. Hence it is essential to design the drainage system properly. The excess water in the root zone is removed by the subsurface drainage system and that above the land surface is removed by surface drainage system. The present study is planned to evaluate drainage needs in the soils of Konkan region by determining surface drainage coefficient through rainfall analysis for Thane district.