1. Hydrology and Fluvial Morphology Key Terms Flashcards
9696 - Cambridge AS Geography
Drainage Basin System
An area of land defined by a ridge line (watershed) that channels all surface water to a single collection point, like a river mouth, lake, or ocean.
Outputs
Water that leaves the drainage basin system.
Evaporation
The process where liquid water changes into a gas and enters the atmosphere.
Evapotranspiration
The combined process of evaporation (from the soil and water surfaces) and transpiration (release of water vapor from plants).
River Discharge
The volume of water flowing past a specific point in a river at a given time.
Stores
Locations within the drainage basin system where water is temporarily held.
Interception
Water caught by vegetation leaves and branches, which evaporates back into the atmosphere.
Soil Water
Water held in the spaces between soil particles.
Surface Water
Water visible on the Earth’s surface, like in streams, lakes, and oceans.
Groundwater
Water stored underground in saturated rock and soil layers.
Channel Storage
Water temporarily held within the channel of a river or stream.
Flows
The movement of water within the drainage basin system.
Throughfall
Precipitation that drips through the canopy of vegetation and reaches the ground.
Stemflow
Precipitation that runs down the stems of plants and reaches the ground.
Overland Flow
Water that flows over the land surface because infiltration cannot keep up with precipitation.
Channel Flow
Water moving within the channel of a river or stream.
Infiltration
The process of water soaking into the ground.
Percolation
The downward movement of infiltrated water through soil and rock layers.
Throughflow
Water that moves laterally through soil layers above the water table.
Baseflow
Groundwater that slowly discharges into streams and rivers, contributing to their flow even during dry periods.
Water Table
The upper boundary of the saturated zone in an aquifer.
Groundwater Recharge
The process by which water infiltrates the ground and replenishes the groundwater table.
Springs
Places where groundwater naturally flows out of the ground.
Discharge Relationships
How the volume of water flowing out of a drainage basin (discharge) changes over time in response to various factors.
Hydrograph
A graph showing the discharge of water from a drainage basin over a period of time.
Storm Hydrograph
A hydrograph that shows the rapid rise and fall of discharge in response to a specific precipitation event (storm).
Annual Hydrograph
A hydrograph that shows the variation in discharge throughout a whole year, reflecting seasonal changes in precipitation and other factors.
Influences on Hydrographs
Factors that affect the shape and characteristics of a hydrograph.
Precipitation Type and Intensity
The form (rain, snow, hail) and amount of precipitation that falls within the drainage basin.
Temperature
Air temperature affects rates of evaporation, transpiration, and infiltration.
Evaporation
The process where liquid water changes into a gas and enters the atmosphere.
Transpiration
The release of water vapor from plants.
Evapotranspiration
The combined process of evaporation and transpiration.
Antecedent Moisture
The amount of water already stored in the soil and groundwater before a precipitation event.
Drainage Basin Characteristics
Physical properties of the drainage basin that influence water flow.
Size and Shape
Larger and more circular basins tend to have slower and more sustained discharge.
Drainage Density
The total length of streams per unit area of land within the basin. Higher density indicates faster drainage.
Porosity and Permeability of Soils
Porosity is the space between soil particles; permeability is how easily water can flow through those spaces. Both influence infiltration and runoff.
Rock Type
Different rock types have varying permeability and storage capacity for water.
Slopes
Steeper slopes promote faster overland flow and less infiltration.
Vegetation Type
Vegetation can intercept precipitation, influence infiltration rates, and affect evapotranspiration.
Land Use
Urbanization with paved surfaces increases runoff and reduces infiltration.
River Channel Processes
The physical processes that shape a river channel, including erosion, transportation, and deposition of sediment.
Channel Processes
Specific mechanisms by which rivers erode, transport, and deposit sediment.
Erosion
The wearing away of rock and soil by flowing water.
Abrasion/Corrasion
Erosion caused by rocks and pebbles grinding against the river bed and banks.
Solution
Chemical dissolving of rock minerals by water.
Cavitation
Erosion caused by the rapid formation and collapse of bubbles in the water.
Hydraulic Action
The force of flowing water physically breaking apart rock and soil.