# Storm Hydrograph Essay

2443 Words10 Pages
Explain how the shape of storm hydrograph is influenced by different factors A storm hydrograph is used to illustrate the discharge over a period of time at a given point of a river responding to a particular storm event. It represent the time between the peak rainfall and the peak discharge (known as lag time) that varies due to different weather conditions, environmental factors and human activity which is also shown in the shape of a storm hydrograph. Figure 1: Storm Hydrograph A &amp; Storm Hydrograph B Storm Hydrograph A Storm Hydrograph B 2) 2) 4) 5) 3) 1) 1) 1) Peak rainfall 2) Peak discharge 3) Lag Time 4) Rising limb 5) Falling limb Hydrograph A represents an event with short lag time, steep rising limb and high discharge whereas hydrograph B shows a long lag time, gentle rising limp and low discharge. The discharge of a river is calculated by volume of a river times velocity of a river. All these elements are highly influenced by the below stated conditions. The main structure of a drainage basin, one of the bullets factors, which can affect the shape of storm hydrograph. It is separated in three different factors, size, shape and relief. The size of a drainage basin determines the distance the water has to cover from the precipitation falling point and the hydrograph flow station. Naturally, the lager the drainage basin the longer the way the water needs to cover the longer the taken time to reach the measuring location. This also means the lager the drainage basin the longer the lag time which can be referred to hydrograph B. Hydrograph A represents more likely a small drainage basin where the water only has to travel a short distance. The shape of a