5.2 Flashcards
(28 cards)
What type of system is the drainage basin?
Open system, within the global hydrological cycle.
What is precipitation?
The input into a drainage basin system. It includes all forms of moisture entering: hail, snow, frost, sleet and rain.
What is interception storage?
The storage of water when it lands on vegetation (or structures like buildings) before it reaches the soil. It is a temporary store before evaporation or stem-flow.
What is surface storage?
The storage of water on the surface including puddles, ponds and lakes.
What is soil water (sub-surface) store?
The storage of water in soil. Water is held in small gaps between soil particles.
What is groundwater storage?
The storage of water in the ground rocks of permeable rock. The water is held in cracks (limestone) bedding planes (sedimentary rock) or pores (chalk). Rocks with lots of water storage are called aquifers.
What is channel store?
The storage of water in the river channel. As water is being transported to the sea it is a storage of water.
What is vegetation store?
The storage of water in the vegetation. Plants and trees take up water through their roots and water is stored here.
What is surface run-off?
The horizontal flow of water over the surface of the land either in little channels or over the whole surface - this is usually a quick flow.
What is throughflow/stem flow?
The downwards flow of water moving downwards from interception storage to the surface
What is soil throughflow?
The horizontal flow of water moving through soil (between the particles) towards the river
What is infiltration?
The downwards movement of water from the surface into the soil.
What is percolation?
The downwards movement of water from the soil to the permeable ground rock
What is groundwater flow?
There horizontal movement of moving through the rocks (cracks/bedding planes/pores) slowly towards the river. This is the movement of water below the water table sideways to the river.
What is channel flow?
The movement of water in the river channel moving towards the sea.
What is evaporation?
The output of water when water is heated and turned from a liquid into a gas.
What is transpiration?
The output of water where moisture is taken into plants through their roots, moved to the leaves by capillary action and then evaporates from the leaves into a gas.
What is evapotranspiration?
The combined output of water from evaporation and transpiration.
What is river discharge?
The output of water from a river channel out to sea.
What is the dew point?
The point of which water turns from gas to liquid.
Describe the process of conventional rainfall?
- The Earth’s surface heats the air above it.
- The heated air rises, expands and cools. This causes condensation to take place.
- Further ascent causes more expansion and more cooling to take place.
- Cool air descends and replaces the warm air.
Describe the process of cyclonic rainfall?
- Warm air front rises over cold air (as it is less dense).
- It then expands cools and condenses.
- This means clouds and rain form.
Describe the process of orographic rainfall?
- High mountains force air to higher altitudes.
- This causes the air to cool & condense.
- Clouds and rain forms
- As a result a rain shadow forms past the mountain.
How does interception affect flows in a drainage basin?
Interception:
- Level of rainfall
(High levels = overcome maximum storage capacity)
(Low levels = Allows leaves and stems to be able to storage precipitation, before it evaporates, without reaching the surface) - Volume of vegetation
(High volumes of plants = high levels of interception and increased effectivity)
(Also different types of vegetation influences interception amounts - e.g. denser types of vegetation (coniferous forests) intercept more than less dense vegetation (deciduous forests).
