Hydrologic Cycle

______: primary medium for the movement of heat and matter among system components

• Exists in all phases of matter, but phase changes consume/release ________

Water; energy

Ocean Temperature Stability

• Land surfaces heat up and cool down ______ than the ocean

• _________: the more distant from the ocean, the more extreme the temperatures will be (all other factors equal)

  • Coastal towns record a _______ range of temperatures than areas further from the coast

• Sea breezes and land breezes: local wind systems created by the difference between land and sea _______

• The air rises over the warm surface (land during the ____, sea during the ______)

faster; Continentality; narrower; temperatures; day; night

Specific Heat Capacity of Water

• ______ ______ _______: the amount of energy that mush be added (in the form of heat) to raise the temperature of 1g of H20 by 1 degree Celsius

• Water has the ______ specific heat capacity of any liquid

  • It takes water a ______ time to heat and a ______ time to cool (this is why ocean temperatures are relatively ______)

• ______ _______: the energy required to change the temperature of a substance with no phase change (the phase remains constant, but the temperature changes)

• ______ ______: heat energy released or absorbed during the transition from one phase to another. There is no change in temperature, just energy required to cause the phase change (the temperature remains constant, but the phase changes)

  • This is why sweating (________) cools your body

Specific heat capacity; highest; long; long; stable; Sensible heat; Latent heat; evaporation

• Phase Changes

  • When water changes phase, it can absorb or release _______ (q)

  • Evaporation ______ heat, thus it has a cooling effect on your skin

  • The heat energy is transferred to ______ molecules, therefore Joules of heat is ______ from the environment (your sweaty skin)

  • 1 calorie of heat is needed to raise ____ gram of water 1 degree Celsius

    • The calories on nutrition labels are _______

    • 1 calorie = ______ Joules (J)

heat; absorbs; water; lost; 1; kilocalories; 4.184

Latent heat, sensible heat, and convection transfer heat and matter through the _______ cycle

hydrological

Rivers and streams: channels where water move _______

downslope

• ______: standing bodies of water that occur on land

  • Natural lakes are _______

    • Can form when one of the following _____ a river or stream:

      1. Land______

      2. ______ deposits sediment

      3. ______ or other animals

      4. Fault thrusts material ____

      5. Lava flow ______ the flow of water

  • ______ are created by engineered dams

  • ________: shallow bodies of standing water where vegetation grows above the water level

Lakes; short-lived; dams; slide; Glacier; Beavers; up; blocks; Reservoirs; Wetlands

• Natural Eutrophication vs. Cultural Eutrophication

  • Over time, lakes fill with sediment and nutrient levels ______

  • _______ ________: the natural process of a lake collecting sediment, eventually filling in completely, cane take centuries

  • ______ ________: human activities can greatly accelerate this natural process. Human contribution of sediment and nutrients. Takes place over much shorter timescales

    • Presence of ____ nutrients, usually ______ and/or phosphorous, can cause lakes to become _____ with vegetation

    • Usually related to ______ fertilizer use, or improper sewage disposal/runoff

    • Once vegetation dies, decomposers break it down, _______ oxygen from the water. This can lead to total depletion of the ______ _______, causing fish and other aquatic species to ____

increase; Natural Eutrophication; Cultural Eutrophication; excess; nitrogen; choked; excess; consuming; dissolved oxygen; die

• Watershed, drainage basin, or catchment: area _____ by a river

• Watershed divides or drainage divides: watersheds are ______ by topographic highs

• ______ ______ watershed is the largest in the US, draining 2.3 million km^2 (1.15 mi^2)

drained; separated; Mississippi River

• Impacts of Urbanization

  • _______: the conversion of natural areas to urban areas

    • Impacts _____ ______ by altering

      1. Water _____ paths

      2. _____ temperature and chemistry

      3. Water ______ (contamination, turbidity (sediment))

      4. habitat

Urbanization; surface water; flow; Water; quality

• Flooding

  • Factors that ____ flood risk:

    1. Urbanization (increase in _______ surfaces)

    2. _______ ground

    3. ______ change

  • Factors that ______ flood risk:

    1. ______ of water

    2. _________ization

    3. ______ change

increase; impervious; Saturated; Climate; decrease; Diversion; Channel; Climate

• ______ ______: used to determine floods and water flows

  • Installed throughout the country

  • The USGS maintains over _______ stream gauges through the country

Stream Gauges; 7,000

• ______ ______: associated with raid rise in the water height of a stream

  • Water can rise quickly due to _______ rainfall, an _______ of water to soak into the ground, or dam ______

  • Can occur in an area where _____ a drop of rain has fallen if an event happened in another part of the watershed

Flash Flood; excessive; inability; failure; not

• Stormwater Management

  • ________: rainwater or melted snow that runs off developed areas, like roofs, parking lots, lawns, and streets

  • _____ _______: increase flooding by prohibiting stormwater from soaking into the ground

  • _____ ________: encourages the retention of stormwater so that it can soak into the ground

    • _______ flood risk but can introduce ________ to the subsurface

    • Rain gardens or ______ areas: designed to ________ hold water while it's raining, and allow it to slowly soak into the subsurface over time

      • Include an installed filter of _____ and gravel to trap large particles (litter) and sorb some contaminants

    • ______ pavers and permeable pavement: ______ ground covers that allow water to flow ______ them, instead of forcing it to flow over them

      • Stormwater _____ into the underlying sand and gravel beneath

Stormwater; Impervious surfaces; Green infrastructure; Reduces; contaminants; bioretention; temporarily; sand; Permeable; engineered; through; soaks

• _______: water that exists below the ground

  • Is stored in the _______ (empty space) between rocks and sediments

  • _____ _______: boundary between where all voids are saturated (below) and where void space is filled with air (above)

Groundwater; voids; Water table

• Recharge and Discharge

  • ______: underground reservoirs of water for dinking water and irrigation purposes

  • Groundwater can be fresh or ______

  • ______: when surface water becomes groundwater

    • This is how groundwater is ______

  • Groundwater becomes surface water through the process of ______

    • Can happen at a ______ or within a permanent stream's bed

  • _______: place where the water table intersects the ground surface, resulting in the discharge of groundwater

Aquifers; saline; Recharge; replenished; discharge; spring; Spring

• Connecting Surface Water and Groundwater

  • The ______ of the water table fluctuates based on:

    1. The amount of ______ (rainy vs. dry season)

    2. The amount of _________ (growing season)

  • The ________ of the water table dictates the water level of most surface water

  • _____ ______: the water table is above the bottom of the stream. Groundwater discharges to the stream

  • _________: groundwater is recharged from the stream

    • In a losing stream that is ______ from the water table, there is an unsaturated zone between the bottom of the stream and the water table. Groundwater is recharged from the stream. This can happen most commonly in ______ areas

elevation; rainfall; evapotranspiration; position; Gaining Stream; Losing Stream; disconnected; arid

• ______: place where the water table intersects the ground surface, resulting in the discharge of groundwater

• When we consider aquifers for their potential to supply water for ______ use, we most consider their:

  • ______: the amount of void space in a material

  • _______: how well-connected the voids of the material are

Spring; human; Porosity; Permeability

• Types of Aquifers:

  • _____ _______: not restricted above it

  • ______ ______ (also aquicludes or aquitards): layers with low porosity and low permeability, which impede the flow of water, create separate aquifers

  • ______ ________: have confining units above and below them. They have a restricted recharge area and are generally more protected from contamination. They are more commonly used for drinking water resources

  • ______ _______ (or potentiometric surface): the elevation that a confined aquifer would rise to if it was unrestricted

  • ______ _______: flows without needing to be pumped because its wellhead is below the piezometric surface

Unconfined aquifers; Confining units; Confined aquifers; Piezometric surface; Artesian Well

• Aquifer Recharge Rates

  • For ______ aquifers only

  • Generally, the recharge rate ______ and the residence time _______ for confined aquifers

unconfined; decreases; increases

• Groundwater Pumping

  • _______: lowering of the groundwater table

    • Can happen when pumping ________ recharge

    • In the immediate vicinity of an over pumped well, a cone of ______ forms

    • With continued pumping, the cone of depression grows ______ and the water table _____

    • _______ _______: when pumping exceeds recharge

Drawdown; exceeds; depression; larger; lowers; Groundwater mining

• ________: when groundwater is removed from the subsurface, the sediment can compact. This results in a lowering of the land surface

  • Impacts ______ ______ flow and can cause _______ flooding risk

  • Usually _______ and irreversible

Subsidence; surface water; increased; permanent

• In ______ aquifers, freshwater floats on _____ of the saltwater because saltwater is ______ than the fresh water

  • Under normal conditions, freshwater discharges at the ______

  • Over pumping of coastal wells can ______ this freshwater discharge and even pull saltwater _____ from the coast

coastal; top; denser; coast; prohibit; inland

_______ _______: excessive pumping of coastal wells can draw saltwater into the well, rendering it useless for drinking water supply

Saltwater intrusion

• The __________ Principle

  • The relationship between the height of freshwater about sea level (h) and the depth of freshwater below level (z) can be expressed: z = 40 x h

  • A 1 ft reduction in the ________ surface (h) results in a 41-ft depletion in the _______ of the coastal aquifer

Ghyben-Herzberg; groundwater; thickness

• _____: constructed features that limit or significantly reduce the amount of water that can flow along a stream's natural course of flow

  • Built for a variety of reasons, including:

    1. ______ supply

    2. Flood ______

       • Dams can be constructed to _____ back flood waters

       • This protects areas ______ of the dam (by holding the water back) but threatens areas _______ of the dam

       • Preventing water from rushing downstream also encourages it to _______ to groundwater

    3. Irri______

    4. Navi______

       • Dams can be placed to flood areas to make transportation _____

       • The _____ ______ is an example: in 2025, 13,404 vessels transited the canal. It has been in operation since 1914

       • Without the Panama Canal, ships would have to go around South America to move from the ______ to the _____ Ocean, or vice versa

       • _____ of freight carried in the US is through Army Corps of Engineers inland waterways

    5. ________ control

    6. Generation of ______

       • As water moves from _____ elevation (in the reservoir) to ______ elevation (on the downstream side of the dam), it spins a ______, which generates electricity

       • Hydroelectric power is a source of _______ energy

Dams; Water; control; hold; downstream; upstream; recharge; gation; gation; easier; Panama Canal; Atlantic; Pacific; 15%; Sedimentation; electricity; higher; lower; turbine; renewable

• Dam Failure

  • Failure of a dam results in ______ to life, property, and the environment

  • Failure can occur due to ______ construction, poor maintenance, or catastrophic flow of _____

  • Dam failures not only risk public safety, but they can _____ our economy millions of dollars in damages

  • Failure is not just limited to damage to the dam itself. It can result in the impairment of many ______ infrastructure systems, such as roads, bridges, and water systems

  • When a dam fails, _______ must be devoted to the prevention and treatment of public _______ risks as well as the resulting ______ consequences

  • ______ ______, Georgia Dam Failure

    • On November 6, 1977, the Kelly Barnes Dam in Toccoa Falls, Georgia failed

    • The failure killed 39 people and caused $2.5 million in damages. The cause is officially unknown, but the dam was evaluated to have been in _____ condition

    • President Jimmy Carter directed the US Army Corps of Engineers to inspect the nation's dams

    • The _____ ______ _____ _____ was established by Congress in 1996

    • In 2025 FEMA offered $7.48 million to support state and territorial dam safety programs

damage; poor; water; cost; other; resources; health; structural; Toccoa Falls; poor; National Dam Safety Program;

• ________: when water backs up behind a dam, there is a resulting pool of water

Reservoir

• ______ _______, Oregon

  • Once the third largest salmon-producing river on the West Coast, supporting chinook and coho salmon and steelhead trout

  • The Chinook people named the river for its _______

  • Four dams along the Klamath River have been/are being ______

Klamath River; swiftness; removed

• Dam Removals

  • Over _______ dams have been removed in the US since 1912

  • Removing aging/outdated dams eradicates the risk of dam failure and _______ natural ecosystems, including migratory pathways for fish

  • ______ leads the country for the number of dam removals, with 390 removed between 1912 and 2023. It was the site of the 1889 ______ ______, which killed 2,209 people

2,000; restores; Pennsylvania; Johnstown Flood