1.6 - Yukon River Regimes Flashcards
River Regimes
The annual variation in the discharge of a river at a particular point.
What Affects River Regimes
Global precipitation & evapotranspiration patterns
Anthropogenic climate variability
Human activity
The Global Water Budget
Allows rivers to have distinct annual flow rates depending on latitudes and topography.
The Yukon (Alaska & Canada)
Starts in the Canadian Rockies and flows down into the sea, during November sections of it to freeze over as as result permafrost has a 50-90% coverage over the river.
How Does Climate Cause Regimes To Vary?
The amount of/timing of rainfall.
Temperature determines the amount of evapotranspiration and hence the amount of water learning.
Freezing conditions mean that water flow is suspended.
How Does Geology Cause Regimes To Vary?
Porosity and perviousness of rocks
Permeable rock recharges acquifers and water it’s released steadily
Impermeable rock water flows quickly into the river as a result of rain.
How Do Soils Cause Regimes To Vary?
Deep soils store water and therefore release it slowly leading to steady water flow.
Permafrost prevents percolation and then when it melts there will be a rapid water supply.
River Regimes Complexity
Large basins have complex regimes and cross climate zones e.g. The Nile.
Mountains can provide move water especially changing dry regimes.
Yukon River
High latitude leading to small change in water budget due to limited evaporation and precipitation.
Regime is dependant on glacial melt
Permafrost covers large area
Spring thaw leads till high overland flow
Amazon Regime
Heavy convectional rainfall all year round.
In the South, tropical regime with drier winter seasons.
As well as human factors (land-use & urbanisation).
Nile Regime
Drainage basin is tropical with drier season
Ethiopian Highlands means large runoff flowing downstream.
