Terminology
The discharge is measured at a certain point in a river and is typically time variant.
- Rising limb: The rising limb of hydrograph, also known as concentration curve, reflects a prolonged increase in discharge from a catchment area, typically in response to a rainfall event
- Recession limb: The recession limb extends from the point of inflection at the end of the crest segment to the commencement of the natural groundwater flow (baseflow). It represents the withdrawal of water from the storage built up in the basin during the earlier phases of the hydrograph.
- Peak discharge: the highest point on the hydrograph when the rate of discharge is greatest
- Lag time: the time interval from the center of mass of rainfall excess to the peak of the resulting hydrograph
- Time to peak: time interval from the start of the resulting hydrograph
- Discharge: the rate of flow (volume per unit time) passing a specific location in a river or other channel
Types of hydrograph can include:
- Storm hydrographs
- Flood hydrographs
- Annual hydrographs aka 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)
Read more about this topic: Hydrograph