River management - AQA - GCSE Geography Revision - BBC
A short lag time means water is reaching the river quickly, so there is a greater chance of a flood. Learn about and revise river management, and hard and soft engineering strategies...
Discharge & Hydrographs - Geography AS
Aug 2, 2014 · The lag time is the time difference between the peak precipitation and and the peak discharge. A long lag time indicates that it’s taking a long time for precipitation to enter the river. Conversely, a short lag time indicates that the precipitation is entering the river fairly quickly.
Flood Hydrographs - Internet Geography
Flashy hydrographs have a steep rising limb and a small lag time. This indicates that river discharge increases rapidly over a short period, indicating rainwater reaches the river very quickly. This means the river is more likely to flood.
River Discharge – Storm Hydrograph - A Level Geography
The lag time is the delay between the maximum rainfall amount and the peak discharge. The shape of a hydrograph varies in each river basin and each individual storm event. The hydrographs below show two contrasting environments.
How do lag time and peak discharge relate to flooding?
When there is a short lag time, it means that the rainwater is reaching the river quickly. This could be due to a variety of reasons such as the steepness of the river basin, the type of soil, and the level of urbanisation in the area.
Human management of rivers - Edexcel Hydrographs - BBC
Gentle slopes slow down water transfer making the lag time longer. Drainage basin shape - a high density basin has more streams and rivers which speed up water transfer and shorten lag time.
3C Storm Hydrographs - A-LEVEL GEOGRAPHY REVISION: EDEXCEL
Some hydrographs have very steep limbs, especially rising limbs, a high peak discharge and a short lag time. These are often referred to as 'flashy' hydrographs. In contrast, there are some hydrographs with gently inclined limbs, a low peak discharge and a long lag time.
Hydrographs and Recurrence Intervals - The British Geographer
Flash responses lead to a very abrupt rise in discharge over a short period of time. This can lead to more frequent flood events. The characteristics of the drainage basin will explain how a river responds to a rainfall event.
In this case, we define lag time as the time elapsed between installation or adoption of land treatment at a level projected to reduce nonpoint source pollution and the first measurable improvement in water quality in the target water body.
Hydrographs and River Discharge - Blogger
Nov 17, 2006 · The response of a river to a rainfall event can be measured in terms of the lag time - the time between peak rainfall and peak discharge. Rivers with a short lag time respond rapidly to rainfall events and are therefore more prone to …