PRELIM Flashcards
Evaporation which occurs at a rate controlled by the available water. (plant transpiration may be restricted by low soil moisture)
Actual Evaporation
it forms in the atmosphere when industrial gas emissions combine with precipitating water.
Acid Rain
energy that originates elsewhere and has been transported to a region where it becomes available energy.
Advective Energy
a term to account for the way that the water evaporating off a surface mixes with a potentially drier atmosphere above it through turbulent mixing.
Aerodynamic resistance
Reflectivity of a surface (unit percentage)
Albedo
measure of the capacity to absorb hydrogen ions without a change in pH. This is influenced by the concentration of hydroxide, bicarbonate, or carbonate ions.
Alkalinity
used to denote how useful an area is for recreation and other purposes
Amenity Value
Instrument for measuring wind speed
Anemometer
River flow data used in flood frequency analysis. It takes the highest flow in every year of the period.
Annual maximum series
A layer of unconsolidated or consolidated rock that is able to transmit and store enough water for extraction.
Aquifer
An aquifer that has restricted flow above
Confined Aquifer
An aquifer that has no upper limit.
Unconfined Aquifer
A water resource management technique involving the addition of surface water into an aquifer for storage to be recovered later.
Aquifer storage and recovery
A totally impermeable rock formation
Aquifuge
A geological formation that transmits water at a much slower rate than the aquifer.
Aquitard.
The average rainfall for an area calculated from several different point measurements.
Areal rainfall
Water that flows directly to the surface from a confined aquifer. The water in aquifer is under pressure so it is able to reach the surface of a well.
Artesian water or well.
A North American Space Agency (NASA) satellite used mainly for atmospheric interpretation
Advanced Very High Resolution Radiometer (AVHRR)
The amount of water flowing down a river when it is full to the top of its banks.
Bankfull discharge
The portion of streamflow that is not attributed to storm precipitation, referred to as sloflow.
Baseflow
The process of a raindrop growth through a strong water vapour gradient between ice crystals and small water droplets.
Bergeron process
A measure of the oxygen required by bacteria and other microorganisms to break down organic matter in a water sample. A strong indicator of the level of oragnic pollution in a river.
Biochemical Oxygen Demand (BOD)
The ratio of sensible heat to latent heat. This is sometimes used within a method to measure evaporation from a surface.
Bowen Ratio
A law of physics relating to pressure (P), temperature (T), volume (V), and concentration of molecules in gases.
Boyle’s Law
The volume of water that can be held in the canopy before water starts dripping as indirect throughfall
Canopy Storage Capacity
The forces holding back soil water so that it does not drain completely through a soil under gravity. Its primary cause is surface tension between water and soil surfaces.
Capillary Forces
The area of land from which water flows towards a river and then from that river to the sea. Also known as river basin.
Catchment
Water flowing within a channel. A general term for streamflow or riverflow.
Channel flow
The confinement of a river into a permanent, rigid, channel structure. This often occurs as part of urbanisation and flood protection
Channelisation
The artificial generation of precipitation through provision of extra condensation nuclei within a cloud.
Cloud Seeding
The movement of water from a gaseous state into a liquid state
Condensation
Minute particles present in the atmosphere upon which the water or ice droplets form.
Condensation Nuclei
Precipitation caused by heating from the earth’s surface, leading to uplift of a moist air body
Convective precipitation
A form of molecular bonding where electrons are shared between two atoms in the molecule. This is the strongest form of chemical bond and exists within a water molecule.
Covalent Bonding
Precipitation caused by a low-pressure weather system where the air is constantly being forced upwards.
Cyclonic precipitation
Water that condenses from the atmosphere (upon cooling) onto a surface (frequently vegetation)
Dewfall (dew)
A technique to measure streamflow based on the dilution of a tracer by the water in the stream
Dilution gauging
Is frequently used to denote the amount of water flowing down a river/stream with time.
Discharge
The rainfall that produces stormflow. Term is used in the derivation and implementation of the unit hydrograph.
Effective rainfall
A term used to describe the addition of nutrients to an aquatic ecosystem that leads to an increase in net primary productivity.
Eutrophication
This term is someitmes used to indicate the enhanced addition of nutrients through human activity. This may lead to problems with excess weed and algal growth in a river.
Cultural Eutrophication
The movement of water from a liquid to a gaseous form (water vapor) and dispersal into the atmosphere
Evaporation
A large vessel of water, with a measuring instrument or weighing device underneath that allows you to record how much water is lost through evaporation over a time period.
Evaporation pan
A combination of direct evaporation from soil/water and transpiration from plants. The term recognises the fact that much of the earth’s surface is a mixture of vegetation cover and bare soil.
Evapotranspiration
The actual maximum water content that a soil can hold under normal field conditions. This is often less than the saturated water content as the water does not fill all the pore space and gravity drains large pores very quickly
Field Capacity
A flood event that occurs as a result of extremely intense rainfall causing a rapid rise in water levels in a stream. This is common in arid and semi-arid regions
Flash Flood
An inundation of land adjacent to a river caused by a period of abnormally large discharge or sea enroachment on the land.
Flood
A technique to investigate the magnitude-frequency relationship for floods in a particular river. Based on historical hydrograph records.
Flood Frequency Analysis
A graphical description of the percentage of time a certain discharge is exceeded for a particular river
Flow Duration Curve
The rate of flow of some quantity
Flux
Rate of flow of water as evaporation
Evaporative flux
Relationship between how often and how large a particular event is. (Large floods do not happen very often)
Frequency-magnitude
A computer program which is able to store, manipulate, and display spatial digital data over an area
Geographic Information Systems
The study of landforms and how they have evolved.
Geomorphology
The ratio of the weight of water in a soil to the overall weight of a soil
Gravimetric soil moisture content
Water held in the saturated zone beneath a water table. The area of groundwater is also referred to as water in the phreatic zone.
Groundwater
Water which moves down a hydraulic gradient in the saturated (phreatic) zone
Groundwater flow
The study of hydrological processes operating at the hillslope scale
Hillslope hydrology
The relationship between water velocity and sediment erosion and deposition
Hjulstrom curve
See infiltration excess overland flow
Hortonian overland flow
A measure of the ability of a porous medium to transmit water. This is a flux term with units of m/s. It is highly dependent on water content
Hydraulic conductivity
The wetted perimeter of a river divided by a cross-sectional area
Hydraulic radius
Bonding between atoms or molecules caused by the electrical attraction between negative and positive ion.
Hydrogen bonding
A continuous record of streamflow
Hydrograph
The splitting of a hydrograph into stormflow and baseflow
Hydrograph Separation
A conceptual model of how water moves around between the earth and atmosphere in different states as a gas, liquid, or solid. This can be at the global or catchment scale.
Hydrological Cycle
The science or study of water
Hydrology
The science of streamflow measurement
Hydrometry
The ability of some soils to rapidly swell upon contact with water so that the initial infiltration rate is low.
Hydrophobicity and hydrophobic soils
A method for estimating areal rainfall based on the topography of the area
Hypsometric method
The difference insoil suction at a given water content dependent on whether the soil is being wetted or dried
Hysteresis
The rate of infiltration of water into a soil when a soil is fully saturated
Infiltration capacity
Overland flow that occurs when the rainfall rate exceeds the infiltration rate for a soil.
Infiltration excess overland flow
How much water enters a soil during a certain time interval.
Infiltratrion rate
An instrument to measure the infiltration rate and infiltration capacity for a soil
Infiltrometer
A combination of hydrology and aquatic ecology used to assess how much water, and the flow regime, that is required by a particular acquatic fauna in a river or stream
Instream flow assessment
A form of IWRM that promotes the river catchment as the appropriate organising unit for understanding and managing water-related biophysical processes in a context that includes social, economic and political considerations.
Integrated catchment management
A water resource management paradigm that promotes the coordinated development and management of water, land and related resources in order to maximise the resultant economic and social welfare in an equitable manner without comprimising the sustainability of vital ecosystems.
Integrated water resource management
The interception of precipitation above the earth’s surface. This may be by a vegetation canopy or buildings. Some of this intercepted water may be evaporated; referred to as interception loss.
Interception
A method for estimating areal rainfall based on the known distribution of rainfall within the area
Isohyetal Method
The flood resulting from an ice-dam burst
Jokulhlaup
A spatial statistics technique that identifies the similarity between adjacent and further afield point measurements. This can be used to interpolate an average surface from a series of point measurements
Kringing
A series of satellites launched by the NASA to study the earth’s surface
LANDSAT
The energy required to produce a phase change from ice to liquid water, or liquid water to water vapor.
Latent heat
When water moves from liquid to gas and energy is los
Negative flux
When water moves from gas to liquid produces a what
Positive heat flux
See throughflow
Lateral flow
A period of extreme low flow in a river hydrograph
Low flow
A technique to investigate the magnitude-frequency relationship for low flows in a particular river.
Low flow frequency analysis
A device for collecting water from the pore spaces of soils and for determining the soluble constituents removed in the drainage.
Lysimeter
Large pores within a soil matrix, typically with a diameter greater than 3mm
Macropores
A representation of the hydrological processes operating within an area.
Model
An agricultural technique involveing the provision of rapid subsurface drainage routes within an agricultural field.
Mole drainage
The total electromagnetic radiation received at a point. This includes direct solar radiation and re-radiation from the earth’s surface.
Net radiation
An instrument to estimate the soil water content using a radioactive source of fast neutrons.
Neutron probe
The evaporation that occurs above a body of water such as lake, stream, or the ocean
Open water evaporation
Precipitation caused by an air mass being forced to rise over an obstruction such as a mountain range
Orographic Precipitation
Water which runs across the surface of the land before reaching a stream. This is one form of runoff
Overland flow
The downstream dip is dissolved oxygen content that can be found after the addition of organix pollution
Oxygen sag curve
The idea that only certain parts of a catchment area contribute overland flow to stormflow
Partial areas concept
River flow data used in flood frequency analysis.
Partial duration series
See stormflow
peakflow
Area where the water table is held above a regional water table, usually due to small impermeable lenses in the soil or geological formation
Perched water table
The concentration of hydrogen ions within a water sample. A measure of water acidity on an inverse logarithmic scale
pH
The area beneath a water table
Phreatic zone
A tube with holes at the base that is placed at depth within a soil or rock mantle no measure the water pressure at a set location
Piezometer
The rapid movement of water through a hillslope in a series of linked pipes.
Pipeflow
The percentage of pore space
Porosity
Evaporation which occurs over the land’s surface if the water supply is unrestricted.
Potential evaporation
Movement of water from the atmosphere to the earth’s surface.
Precipitation
Precipitation in liquid form.
Rainfall
The rate at which rainfall occurs. A depth of rainfall per unit time, most commonly mm/hr
Rainfall intensity
An instrument for measuring the amount of rainfall at a point for a period of time.
Rain gauge
An uneven distribution of rainfall caused by a large high landmass.
Rain shadow effect
The relationship between river stage (height) and discharge
Rating curve
The period after a peak of stormflow where the streamflow values gradually recede.
Recession limb
How close to fully saturated the atmosphere is
Relative humidity
The start of a stormflow peak
Rising limb (of hydrograph)
A large natural stream of water flowing over the surface and normally contained within a river channel
River
The area of land from which water flows towards a river and then in that river to the sea. Also known as the river catchment
River Basin
A term used in equations such as Chezy and Manning’s to estimate the degree that water is slowed down by friction along the bed surface
Roughness coefficient
The movement of liquid water above and below the surface of the eath prior to reaching a stream or river
Runoff
The build up of salts in a soil or water body
Salination
The interpretation of ground characteristics based on measurements of radiation from the earth/atmosphere.
Satellite remote sensing
Overland flow that occurs when a soil is completely saturated.
Saturated overland flow
The maximum amount of water that the soil can hold. It is equivalent to the soil porosity, which assumes that the water fills all the pore space within a soil
Saturated water content
The maximum vapor pressure possible. The saturation point of an air parcel is temperature-dependent and hence so is the saturation vapor pressure
Saturation vapor pressure
The heat which can be sensed or felt. This is most easily understood as the heat we feel as warmth.
Sensible heat
The rate of flow of the sensible heat
Sensible heat flux
Precipitation in solid form. (vertical depth of liquid water)
Snowfall
An instrument used to measure the depth of snow accumulating above a certain point
Snow pillow
Heat released from the soil having been previously stored within the soil
Soil heat flux
A measured curve describing the relationship between the capillary forces and soil moisture content.
Soil moisture characteristic curve (suction moisture curve)
The amount of water required to fill the soil up to field capacity.
Soil moisture deficit
A measure of the strength of the capillary forces. A dry soil exerts a high soil suction
Soil Suction
(Moisture tension or soil water tension)
Water in the unsaturated zone occurring above a water table. Also referred to as water in the vadose zone.
Soil water
The amount of energy required to raise the temperature of a substance by a single degree
Specific heat capacity
French satellite to study the earth’s surface
SPOT
Water lebel height of a river
Stage
Rainfall that intercepted by stems and branches, and flows down the tree trunk into the soil
Steamflow
The restriction a plant places on its transpiration rate through opening and closing stomata in the leaves.
Stomatal or canopy resistance
A term in the water balance equation to account for water that is not a flux or is very slow moving.
Storage.
The length of time between rainfall starting and ending within a storm
Storm duration
The portion of streamflow that can be attributed to as storm precipitation.
Stormflow
A small river
Stream
Water flowing within a stream channel. Often referred to as discharge
Streamflow
A remote sensing technique that uses radar properties, usually of microwaves.
Synthetic Aperture Radar (SAR)
A unit hydrograph derived from knowledge of catchment characteristics rather than historical hydrograph records.
Synthetic unit hydrograph
An instrument used to measure the soil moisture tension
Tensiometer
A method of estimating average rainfall for an area based on the spotial distribution of rain gauges.
Thiessen’s Polygons
The precipitation that falls to the ground either directly or indirectly
Throughfall
Water which runs to a stream through the soils. This is frequently within the unsaturated zone.
Throughflow
A method to estimate the soil water content based on the interference of propagated electromagnetic waves due to water content.
Time domain reflectometry (TDR)
The amount of solids dissolved within a water sample. This is closely related to the electrical conductivity of water sample.
Total Dissolved Solids (TDS)
The amount of solids suspended within a water sample. This is closely related to the turbidity of a water sample.
Total Suspended Solids (TSS)
The movement of liquid water from a plant leaf to a water vapor in the atmosphere.
Transpiration
The cloudiness of a water sample
Turbidity
An instrument that measures stream discharge based on the alteration to a propagated wave over a known cross section
Ultrasonic Flow Gauge
A model of stormflow in a particular catchment used to predict possible future storm impacts.
Unit Hydrograph
Area between the water table and the earth’s surface. The soil/rock is normally partially saturated
Vadose Zone
pressure exerted within the parcel of air by having the water vapor present within it. The more water vapor is present the greater the vapor pressure.
Vapor Pressure
The difference between actual vapor pressure and saturation vapor pressure
Vapor pressure deficit
The idea that only certain parts of a catchment area contribute overland flow to stormflow and that these vary in space and time, compare to the partial areas concept.
Variable source areas concept
A technique to measure instantaneous streamflow through measuring the cross-sectional area and the velocity through the cross section
Velocity-area method
The ratio of the volume of water in a soil to the overall volume of a soil.
Volumetric soil moisture content
A mathematical description of the hydrological processes operating within a given timeframe. Normally includes precipiration, runoff, evaporation, and change in storage.
Water balance equation
The surface that differentiates between fully saturated and partially saturated soil/rock
Water table
Water in a gaseous form
Water vapor
A tube with permeable sides all the way up so that water can enter or exit from anywhere up the column
Well
The total perimeter of a cross section in a river
Wetted perimeter
The soil water content when plants start to die back or wilt
Wilting Point
The height within a canopy at which wind speed drops to zero
Zero plane displacement
