Factors affecting the drainage basin and storm hydrographs

Factors affecting the drainage basin and storm hydrographs

1. Deforestion

   • Less trees means less of the water is intercepted or absorbed by trees for evapotranspiration
   • Deforestation can also lead to less rainfall

2. Agricultural Practises

   • Poor practises such as compacted soil from livestock can lead to more/quicker runoff

3. Soil depth, type and condition

   • Thin impermeable soil means less infiltration. If the soil is already damp from antecedent rainfall there will be even less infiltration

4. Urbanisation

   • More urbanisation means more impermeable surfaces in towns and possibly drains that will move water faster into the river

5. Lithology

   • Impermeable rocks means there is less percolation

6. Vegetation type

   • Deciduous woodland will suffer more moisture loss than moorland vegetation

7. Season

   • In the summer months there is more evapotranspiration, meaning more water will be absorbed by plant life

8. Amount/intensity of rainfall

   • More rainfall means more water in the drainage basin

9. Presence of stores (Lakes, swamps)

10. Climate

    • A damper climate means more rain, it can also allow more evapotranspiration

11. Drainage Basin Density

    • The more streams in the drainage basin, the more water that reaches the river

12. Snow Melt

    • Fast snow melt can increase the amount of water reaching the river