Drainage Basin Flashcards
Watershed
The boundary of the drainage basin.
Inputs into the drainage basin
Precipitation
Storage in the drainage basin
Interception Vegetation stores Surface storage Groundwater storage Channel storage
Flows and processes in the drainage basin
Surface run off Through fall Stem flow Infiltration Percolation Groundwater flow Based low Inter flow Channel flow
Outputs from the drainage basin
Evapotranspiration
Transpiration
River discharge
Interception
When precipitation lands on vegetation or buildings before it reaches the soil.
Surface storage
Includes water in puddles, ponds and lakes
Groundwater storage
Water stored in the ground, either soil or rocks. The water table is the top surface of the zone of saturation.
Channel storage
Water held in the channel of a river
Surface run off
Water flowing over the land. Also called overland flow. Increased in urban areas.
Throughfall
Water dripping from one leaf to another through the vegetation
Infiltration
Water soaking into the soil. Infiltration rates are influenced by soil type, soil structure and soil saturation.
Percolation
Water seeping through through soil into the water table
Groundwater flow
Water flowing slowly through the water table through permeable rock.
Base flow
Groundwater flow that feeds into river banks and beds
Interflow
Water flowing downhill through permeable rock above the after table
Channel flow
Water flowing in the rivers channel
Evaporation
Water turning into vapour, liquid to gas
Transpiration
Evaporation from plants leaves, plants and trees take up water through their roots and transport it to their leaves where it evaporates into the atmosphere.
Drainage basin
An area of land that is drained by a river and its tributaries. It is an open system
Characteristics of a drainage basin
Larger - more precipitation
Steep sided - shorter lag time
Circular - more likely to have a flashy hydrograph because all points are the same distance away
