Get Hydrograph Worksheet

Use the article to draw your hydrograph axes on graph paper using a ruler and a pencil. ... Start with the precipitation data in the table below. ... Now, use the discharge data below to draw your line graph. ... You should now have a completed hydrograph.

Hydrographs illustrate river discharge and rainfall over time. Over the short term, a flood or storm hydrograph (figure 1.) can show short-term variations in discharge and rainfall. They cover a relatively short time period, usually hours or days rather than weeks or months.

Physical factors affecting flood hydrograph dynamics Shape. A circular shaped drainage basin leads to rapid drainage whereas a long drainage basin will take time for the water to reach the river. Topography & relief. ... Heavy Storms. ... Lengthy rainfall. ... Snowfall. ... Vegetation. ... Rock type.

The hydrograph of surface runoff resulting from a particular portion of storm rainfall is not affected by concurrent runoff resulting from other portions of the storm. In other words, the total hydrograph of surface runoff is the sum of the surface runoff produced by the individual portions of the excess rainfall.

There are three main components to the hydrograph—rising limb, peak, and falling limb. The falling limb is often referred to as the recession curve, which provides information on the configuration of the karst conduits within an aquifer system, as well as its transmissivity and volume.

These deterministic models have three common elements: the unit hydrograph itself which often has a simple triangular shape defined by time to peak; a losses model which defines the amount of storm rainfall which directly contributes to the flow in the river; and. baseflow (i.e. the flow in a river prior to the event).

Design Flood Estimation Using Unit Hydrograph Approach The following steps are involved in the estimation of design flood hydrograph: (i) Derive the design unit hydrograph. (ii) Derive the design storm. (iii) Compute excess design rainfall subtracting the design losses from the design rainfall.

Hydrographs Peak discharge. ... Peak rainfall – maximum amount of rainfall (millimetres). Lag time - the time taken between peak rainfall and peak discharge. Rising limb - shows the increase in discharge on a hydrograph. Falling limb - shows the return of discharge to normal/base flow on a hydrograph.