runoff and hydrograph in hydrology / direct runoff hydrograph / unit hydrograph S curve hydrograph

Описание: In this video we are discussed about what is mean by runoff and types of river based on the flow characteristics . what is mean by hydrograph ,direct runoff hydrograph ,unit hydrograph ,instantaneous unit hydrograph, synthetic unit hydrograph and how to draw the hydrograph and what are the procedures to convert the hydrograph to unit hydrograph are discussed.

A hydrograph is a graph showing the rate of flow (discharge) versus time past a specific point in a river, channel, or conduit carrying flow. The rate of flow is typically expressed in cubic meters or cubic feet per second (cms or cfs). It can also refer to a graph showing the volume of water reaching a particular outfall, or location in a sewerage network. Graphs are commonly used in the design of sewerage, more specifically, the design of surface water sewerage systems and combined sewers.

Discharge: the rate of flow (volume per unit time) passing a specific location in a river, or other channel. The discharge is measured at a specific point in a river and is typically time variant.
Rising limb: The rising limb of the hydrograph, also known as concentration curve, reflects a prolonged increase in discharge from a catchment area, typically in response to a rainfall event.
Peak discharge: the highest point on the hydrograph when the rate of discharge is greatest.
Recession (or falling) limb: The recession limb extends from the peak flow rate onward. The end of stormflow (a.k.a. quickflow or direct runoff) and the return to groundwater-derived flow (base flow) is often taken as the point of inflection of the recession limb. The recession limb represents the withdrawal of water from the storage built up in the basin during the earlier phases of the hydrograph.
Lag time: the time interval from the maximum rainfall to the peak discharge.
Time to peak: time interval from the start of rainfall to the peak discharge.

Types of hydrographs include:

Storm hydrographs
Flood hydrographs
Annual hydrographs a.k.a. regimes
Direct Runoff Hydrograph
Effective Runoff Hydrograph
Raster Hydrograph
Storage opportunities in the drainage network (e.g., lakes, reservoirs, wetlands, channel and bank storage capacity)