ABSTRACT
In First World countries, the geometric design team may include a hydrologist. This person would be responsible for determining the size of the catchment area for a drainage structure. From this and considerations of return period, time of concentration and intensity of precipitation, the magnitude of the flood to be accommodated could be determined and hence the drainage structure appropriately sized. In other countries where technical expertise is often in short supply, it is frequently necessary for the geometric designer to undertake the design of the storm water system without the benefit of this expert input. An ability to quantify the characteristics of the catchment area of a drainage structure, followed by determination of the quantity of storm water that needs to be accommodated by the structure, is thus necessary. This chapter serves as a brief introduction to hydrology.
