Drainage Basin Processes And Physical Factors Impact On Water Cycle Flashcards
(16 cards)
Drainage basin
Area of land drained by a particular river and its tributary- river catchment
Tributary
Smaller river that flows into a large river
Confluence
Where 2 rivers join
Watershed
Boundary of a drainage basin
Why are drainage basins an open system?
Area that supplies river with water- water found below the water table as well as soil and surface water.
Input of precipitation, outputs evaporation, transpiration
Transport within the global water cycle
Recirculation of water is high in summer months
Water from the pacific is largely recirculated into the same ocean
Drainage basin shape
More circular basins lead to more flashy hydrography than long and thin
Each point in drainage basins is roughly equidistant from measuring point on river
Drainage basin relief
Steep sides tend to have flashier hydrographs
Water flows quicker on steep slopes
Drainage density
Basins that have high drainage density have flashy hydrographs
Antecedent rainfall
If the drainage is basin is already saturated by antecedent rainfall then overland flow inceases
Soil and rock type
If the soil or rock type within the river is impermeable overland flow will be higher
Through flow and infiltration will decrease
Vegetation
Thick vegetation cover in drainage basins will have a significant effect on a storm hydrograph
Vegetation intercepts rainfall holding water on leaves
Precipitation
The amount of intensity of precipitation can affect storm hydrographs
Heavy storms entering a drainage basins will can result in higher discharge
Size of drainage basin
Large drainage basins catch more precipitation so have higher peak discharge
Drought
Period of below average precipitation, resulting in long shortages in water supply
Impacts of drought
Evapotranspiration decreases
Soil water storage decreases
Vegetation decreases
Ground water flow decreases
