booklet 5 - storm hydrograph

• What does a storm hydrograph show?

  Discharge of a river during a storm
• Why are storm hydrographs important?

  They help predict river responses to storms
• What is base flow in a river?

  Slow moving throughflow of soil water
• What does the rising limb of a hydrograph indicate?

  How quickly a river responds to a storm
• What is bankfull discharge?

  Discharge at which the stream channel overflows
• What characterizes a flashy hydrograph?

  Steep rising limb and high peak discharge
• What characterizes a subdued hydrograph?

  Gentle rising limb and long lag time
• What factors affect the shape of a hydrograph?

  • Small basin size → FLASHY
  • Steep reliefs → FLASHY
  • Low drainage density → SUBDUED
  • Permeable surface → SUBDUED
  • Round basin shape → FLASHY
  • Deforested area → FLASHY
  • Saturated ground → FLASHY
  • Presence of dam → SUBDUED
  • Bare soil → FLASHY
  • Urbanized area → FLASHY
• How does small basin size affect hydrograph shape?

  Leads to rapid water transfer and flashy response
• How does steep relief affect hydrograph shape?

  Causes water to flow quickly to the river
• What effect does low drainage density have on hydrograph shape?

  Results in a subdued hydrograph response
• How does a permeable surface influence hydrograph shape?

  Allows more infiltration and a subdued response
• How does basin shape affect hydrograph response?

  Round shape leads to a flashy hydrograph
• What is the impact of deforestation on hydrograph shape?

  Causes a flashy hydrograph due to runoff
• How does saturated ground affect hydrograph shape?

  Increases overland flow, leading to a flashy response
• What effect does the presence of a dam have on hydrograph shape?

  Controls water flow, resulting in a subdued hydrograph
• How does bare soil influence hydrograph shape?

  Leads to a flashy hydrograph due to runoff
• What is the impact of urbanized areas on hydrograph shape?

  Increases runoff, leading to a flashy hydrograph