Abstract:
The understanding of land phase of the hydrologic cycle plays an important role in design of field drainage system. Physical features(topography, geology; soil characteristics) meteorological (temperature; rainfall, its incidence and
variation in time and space and evaporation)and hydrological conditions of an area determine the varying needs and nature of drainage operations. The salient topographic characteristics which influence watershed process are area, shape, relief and drainage density. Relief as a drainage basin characteristic exercises an influence over runoff and sediment production in a basin. The drainage density is the most important factor characterising the conditions of flood flow formation. The method used for land drainage may be classified in two broad categories-surface drainage and subsurface drainage-depending on the way water is removed. The topographical, climatic and hydrogeological factors which are required for surface and subsurface drainage have been focussed in the present review report.
