There is a delay because it takes time for the water to find its way to the river. This is called lag time. The normal base flow of the river starts to rise when run-off, ground and soil water reaches the river. The underlying geology varies within drainage basins and can be permeable allowing water through or impermeable not allowing water through.
Impermeable rocks encourage greater amounts of surface runoff and a more rapid increase in discharge than permeable rocks. Company Reg no: VAT reg no Main menu. Subjects Shop Courses Live Jobs board. View shopping cart. View mytutor2u. Below is a storm hydrograph for the fictional River Shui:. First is the lag time.
The lag time is the time difference between the peak precipitation and and the peak discharge. Conversely, a short lag time indicates that the precipitation is entering the river fairly quickly. The rising limb is the steep part of the discharge line that has a positive gradient, indicating that the discharge is increasing. The falling limb is the opposite showing that the discharge is falling. The shape of a hydrograph is altered by a few different things.
One factor is the shape of the drainage basin. Drainage basins come in a wide assortment of shapes. The characteristics of a river channel change along its long profile.
Changes occur in the cross profile, wetted…. Save Save. River Discharge River discharge is the volume of water flowing through a river channel. Storm Hydrographs Hydrographs can be used to illustrate discharge. Figure 1. A storm hydrograph. Figure 2. Hydrograph before urbanisation. Figure 3. Hydrograph following urbanisation.
Search for:. Coastal Landforms of Deposition. Sub-Aerial Processes. Drainage Basin Hydrological System. Marine Processes. Landforms of Erosion. Coastal System. Many thanks, Anthony. Drainage basin hydrological cycle Find out about the characteristics of the drainage basing hydrological cycle.
Storm Hydrograph Hydrographs can be used to illustrate discharge.
0コメント