the water cycle and water insecurity Flashcards
precipitation:
moisture in any form.
interception:
temporary storage, as water is captured by plants, buildings and hard surfaces before reaching the soil.
vegetation storage:
any moisture taken up by vegetation and held within plants.
surface storage:
any surface water in lakes, ponds, puddles.
soil moisture:
water held within the soil.
groundwater storage:
water held within permeable rocks (also known as an aquifer).
channel storage:
water held in rivers and streams.
infiltration:
water entering the topsoil, most common during slow or steady rainfall.
throughflow:
also known as inter-flow, water seeping laterally through soil below the surface, but above the water table.
percolation:
the downward seepage of water through rock under gravity, especially on permeable rocks e.g. sandstone and chalk.
stem flow:
water flowing down plant stems or drainpipes.
base flow:
also known as groundwater flow, slow-moving water that seeps into a river channel.
channel flow:
the volume of water flowing within a river channel (also called discharge and runoff).
surface runoff:
also called overland flow, flow over the surface during an intense storm, or when the ground is frozen, saturated or on impermeable clay.
evaporation:
the conversion of water to vapour.
transpiration:
water taken up by plants and transpired onto the leaf surface.
evapotranspiration:
the combined effect of evaporation and transpiration.
river discharge:
the volume of water passing a certain point in the channel over a certain amount of time.
the hydrological cycle:
the amount of water on earth (1385 million km^2) is constant and finite, the hydrological cycle is a closed system as it doesn’t have any external inputs or outputs. water in the system changes its form and can be stored in numerous forms but it cannot leave the hydrosphere and water cannot be added to it.
hydrosphere:
the combined mass of water below, on and above the earth’s surface.
flux:
the rate/speed at which water moves from store to store.
processes:
the way in which the water moves between these stores.
the two processes that drive the water cycle:
solar energy- causes evaporation which leads to condensation and then precipitation.
gravitational potential energy- keeps water moving throughout the system.
cryosphere:
water stored in a frozen state, largely found as a solid but some in liquid form include melt water and lakes.