Water EQ1 Flashcards
factors influencing the infiltration capacity of soil
soil type
permeability of soil
relief
amount of interception
time
moisture already in the soil
seasons
vegetation type
soil compaction
surface run off
the water that leaves a drainage basin
overland flow
surface run off which can be seen
Keswick, River Greta
other factors
relief - higher up you are, more of a slope so more surface run-off, catchment of River Greta is high relief so more surface run off
precipitation
rock types - ordovician rocks, igneous, extrusive, devorian rocks, impermeable rocks which increases surface run off due to lack of percolation, permeable land means less surface run off due to more percolation
rainfall types: orographic
rain, snow or other precipitation produced when moist air is lifted as it moves over a mountain range
as the air rises and cools, orographic clouds form and serve as the source of precipitation
1 - moist air forced to rise
2 - air cools down as it rises
3 - windward side: cold, wet conditions
4 - rain shadow region on leeward side
5 - air warms up as it descends
6 - leeward side: warm, dry conditions
rainfall types: frontal
cold air meets warm air in a weather front
warm air rises so when it joins the cold air it rises above it, higher in the atmosphere you go colder it is so the warm air that has risen in to the atmosphere cools down
1 - warm air forced to rise over cold air
2 - condensation forms clouds
3 - condensation occurs rapidly along front with greater temperature difference
4 - heavy rainfalls along front
Rainfall types: convectional
Heated air from the earth’s structure rises upwards along with the water vapour and gets condensed when it reaches a higher altitude
1 - evaporation
2 - moist air rises
3 - sun heats ground
4 - air cools
5 - condensation occurs forming clouds
Water budget
Balance between inputs and outputs, water availability varies spatially and temporally
Water balance equation
Precipitation = river discharge + potential evapotranspiration +/- soil moisture
Storm hydrograph
At a local level, effects of an individual storm can be shown on a storm hydrograph
Simple regime
Where the river experiences a period of seasonally high discharge followed by low discharge
Typical of rivers where the inputs depend on glacial meltwater, snowmelt or seasonal storms
Rivers within temperate climates, which rise in mountainous regions where summer snowmelt occurs tend to be like this
Complex regime
Where larger rivers cross several different relief and climatic zones, therefore experience the effects of different seasonal climatic events
Factors which affect river regime
Seasonal pattern - respond to amount of precipitation
Glacial meltwater
Seasonal storms
Temperature
Land use
Evapotranspiration
Size of drainage basin
Large drainage basin - larger area so more precipitation, more time needed for discharge
Small drainage basin - smaller area so less precipitation, less distance to travel so short time for discharge
How and why do storm hydrographs vary - physical
Vegetation
Drainage density
Shape
Relief
Soil characteristics
Rock permeability
Size
