The hydrograph is a graph that shows the variation over time of some hydrological information such as: water level, flow rate, sediment load, among others. for a river, stream, ravine or canal, although it typically represents the flow versus time; this is equivalent to saying that it is the graph of the discharge (L / T) of a flow as a function of time. These can be storm hydrographs and annual hydrographs, which in turn are divided into perennials and intermittent. Storm hydrograph due to rain received in the basin.
Allows you to observe:
One mm of precipitation means that one liter of rainwater (1L / m²) has fallen on a surface of one m².
Hydrograms are useful, among other things, to compare the discharge times and peak flows of several streams or watersheds, in order to know the differences between their capacity to respond to floods.
Unitary Hydrogram: Basic response curve to a precipitation unit that describes the way in which a basin returns a rainfall income distributed over time. It is based on the principle that said input-output relationship is linear, that is, they can be added linearly. It is built based on an "S-Hydrogram" which in turn is constructed by breaking down several storms and their actual hydrographs produced.
Synthetic Hydrogram: Unitary Hydrogram estimated according to formulas that include physical parameters of the basin under study as area, length of the main channel, average slope and others. They are the best known synthetic hydrographs: the Triangular of the USDA, the Schneider, the Clark. Determination of the discharge hydrograph of a basin
In some cases it is necessary to determine the total volume of surface runoff generated by a rain in a given time. However, the case in which it is required to know the maximum instantaneous flow of a given avenue is more frequent. Other times a complete knowledge of the hydrograph is required, that is to say the variation in the time of the flow in a certain section in which it is intended to build a hydraulic work or protect an existing good.
The methods used for these calculations are:
wiki
