Introduction
Water table = to which point water reaches in the
ground
Saturated zone = zone below water table
(groundwater)
Unsaturated zone = pores in the soil contain air and
water (soil water)
Hydrological cycle describes the way in which water of the ocean is heated by the sun, evaporates,
and is carried over the earth in atmospheric circulation as water vapour (a greenhouse gas, energy
passes through as shortwave radiation, but it absorbs the longwave, infrared radiation emitted by
the earth surface).
Evaporation in the ocean: the water from the ocean from a liquid or solid state to water vapour,
leaving salt behind. The water vapour condenses and falls as precipitation.
Drainage basin / catchment = a geographical area that drains into a river or reservoir. It includes
drainage basin boundaries.
∆𝑆
Water balance: 𝐼𝑛 = 𝑂𝑢𝑡 + ∆𝑡
∆𝑆
𝑃(+ 𝑆𝑖𝑛 + 𝐺𝑖𝑛 ) = 𝑄 + 𝐸𝑎 + (+ 𝑆𝑜𝑢𝑡 + 𝐺𝑜𝑢𝑡 + 𝑊𝐷)
∆𝑡
The water balance can estimate the effect of several factors like land-use change or climate change.
Hydrological year = one year that starts and ends with a dry season, when storage is lowest, or with
a wet season, when storage is highest.
, Atmospheric water
Atmospheric water = water contained in the air above the land surface, which mostly consists of
water vapour.
Persistence are caused by a positive soil moisture – precipitation feedback.
Dry adiabatic lapse rate = dry air that ascends in the atmosphere expands and cools down at a fixed
rate of 1C for every 100m it rises. It cools because of the heat being distributed over a large column
of air.
Saturated adiabatic lapse rate = air continues to ascend and expand after condensation at a rate of
0.6C for every 100m it rises.
Saturation vapour pressure (es) = pressure exerted by water vapour molecules in the air when the air
is saturated with water vapour.
Dew point = T > 0 C, when condensation happens, which changes water vapour to liquid.
Frost point = T < 0 C, when deposition happens, which changes water vapour to ice.
Cloud = a visible mass of very small
water droplets and/or ice crystals
floating in the atmosphere.
Warm clouds are generated by
collision-coalescence process.
Cloud clouds are generated by
Bergeron-Findeisen process.
Latent heat = heat related to change
in phase of water.
Precipitation
1. Convective precipitation: result of local heating of the air at the surface. In tropical areas and
in the interior of continents.
2. Orographic precipitation: when horizontal airflow is forced to rise over natural barriers, such
as a mountain ridge, which causes precipitation at the windward side and a dry area at the
leeward side, which has a precipitation shadow.
3. Frontal precipitation: where cold and warm air fronts meet
4. Cyclonic precipitation: in a cyclone (low pressure area)
5. Artificial precipitation: made by humans by a proces called cloud seeding
Coriolis effect: in the northern hemisphere winds turn counterclockwise and
in the southern hemisphere clockwise. Air wants to flow from a higher to a
lower pressure and the Coriolis effect determines the direction. There are
different cells on Earth (polar cell, Ferrel cell, Hadley cell) which turn
different directions due to this effect. In the northern hemisphere, air moves
clockwise around high pressure areas and anticlockwise around low pressure
areas (cyclones).
Average recidence time = 9 days
Water table = to which point water reaches in the
ground
Saturated zone = zone below water table
(groundwater)
Unsaturated zone = pores in the soil contain air and
water (soil water)
Hydrological cycle describes the way in which water of the ocean is heated by the sun, evaporates,
and is carried over the earth in atmospheric circulation as water vapour (a greenhouse gas, energy
passes through as shortwave radiation, but it absorbs the longwave, infrared radiation emitted by
the earth surface).
Evaporation in the ocean: the water from the ocean from a liquid or solid state to water vapour,
leaving salt behind. The water vapour condenses and falls as precipitation.
Drainage basin / catchment = a geographical area that drains into a river or reservoir. It includes
drainage basin boundaries.
∆𝑆
Water balance: 𝐼𝑛 = 𝑂𝑢𝑡 + ∆𝑡
∆𝑆
𝑃(+ 𝑆𝑖𝑛 + 𝐺𝑖𝑛 ) = 𝑄 + 𝐸𝑎 + (+ 𝑆𝑜𝑢𝑡 + 𝐺𝑜𝑢𝑡 + 𝑊𝐷)
∆𝑡
The water balance can estimate the effect of several factors like land-use change or climate change.
Hydrological year = one year that starts and ends with a dry season, when storage is lowest, or with
a wet season, when storage is highest.
, Atmospheric water
Atmospheric water = water contained in the air above the land surface, which mostly consists of
water vapour.
Persistence are caused by a positive soil moisture – precipitation feedback.
Dry adiabatic lapse rate = dry air that ascends in the atmosphere expands and cools down at a fixed
rate of 1C for every 100m it rises. It cools because of the heat being distributed over a large column
of air.
Saturated adiabatic lapse rate = air continues to ascend and expand after condensation at a rate of
0.6C for every 100m it rises.
Saturation vapour pressure (es) = pressure exerted by water vapour molecules in the air when the air
is saturated with water vapour.
Dew point = T > 0 C, when condensation happens, which changes water vapour to liquid.
Frost point = T < 0 C, when deposition happens, which changes water vapour to ice.
Cloud = a visible mass of very small
water droplets and/or ice crystals
floating in the atmosphere.
Warm clouds are generated by
collision-coalescence process.
Cloud clouds are generated by
Bergeron-Findeisen process.
Latent heat = heat related to change
in phase of water.
Precipitation
1. Convective precipitation: result of local heating of the air at the surface. In tropical areas and
in the interior of continents.
2. Orographic precipitation: when horizontal airflow is forced to rise over natural barriers, such
as a mountain ridge, which causes precipitation at the windward side and a dry area at the
leeward side, which has a precipitation shadow.
3. Frontal precipitation: where cold and warm air fronts meet
4. Cyclonic precipitation: in a cyclone (low pressure area)
5. Artificial precipitation: made by humans by a proces called cloud seeding
Coriolis effect: in the northern hemisphere winds turn counterclockwise and
in the southern hemisphere clockwise. Air wants to flow from a higher to a
lower pressure and the Coriolis effect determines the direction. There are
different cells on Earth (polar cell, Ferrel cell, Hadley cell) which turn
different directions due to this effect. In the northern hemisphere, air moves
clockwise around high pressure areas and anticlockwise around low pressure
areas (cyclones).
Average recidence time = 9 days
