AP Environmental Science Flashcards: The Hydrologic Water Cycle

What this deck covers

This deck focuses on The Hydrologic Water Cycle, giving you a quick way to review the definitions, rules, and examples that matter most for AP Environmental Science.

How to use these flashcards

Work through these flashcards in short sessions. Try to answer each prompt before flipping the card, then revisit any cards you miss until the explanation feels automatic.

Flashcard 1: Which term refers to the water present beneath Earth's surface in soil pore spaces?

Answer: Groundwater. Water stored in underground soil and rock spaces.

Flashcard 2: Which process involves the transition of water from liquid to gas at the surface?

Answer: Evaporation. Liquid water gains energy and becomes water vapor gas.

Flashcard 3: What is the term for water flowing over the land surface into bodies of water?

Answer: Runoff. Surface water flows due to gravity when soil cannot absorb more.

Flashcard 4: What is the primary force that causes precipitation to fall to Earth?

Answer: Gravity. Gravitational force pulls water droplets downward to Earth.

Flashcard 5: What term describes the downward movement of water through soil?

Answer: Percolation. Gravity pulls water deeper through soil pore spaces.

Flashcard 6: What process accounts for the majority of water vapor in the atmosphere?

Answer: Evaporation. Ocean surface evaporation contributes most atmospheric water vapor.

Flashcard 7: Which term refers to the underground layer of water-bearing rock?

Answer: Aquifer. Permeable rock formation that stores and transmits groundwater.

Flashcard 8: Which component of the hydrologic cycle involves water moving across the Earth's surface?

Answer: Surface runoff. Water flows over land when infiltration capacity is exceeded.

Flashcard 9: What term describes the loss of water from plants to the atmosphere?

Answer: Transpiration. Water exits plant leaves through stomatal pores as vapor.

Flashcard 10: What is the process called when water is absorbed by soil and moves underground?

Answer: Infiltration. Water enters soil and becomes part of groundwater system.

Flashcard 11: What is the term for water returning to Earth's surface from the atmosphere?

Answer: Precipitation. Water falls as rain, snow, sleet, or hail from clouds.

Flashcard 12: Identify the smallest component of the hydrologic cycle by volume.

Answer: Atmospheric water. Contains less than 0.001% of total global water.

Flashcard 13: Identify the term for water that collects in large bodies like lakes and oceans.

Answer: Surface water. Includes rivers, lakes, oceans, and other visible water bodies.

Flashcard 14: What is the primary force that causes precipitation to fall to Earth?

Answer: Gravity. Gravitational force pulls water droplets downward to Earth.

Flashcard 15: Identify the smallest component of the hydrologic cycle by volume.

Answer: Atmospheric water. Contains less than 0.001% of total global water.

Flashcard 16: What is the process of water soaking into the ground called?

Answer: Infiltration. Water penetrates soil surface and moves into underground spaces.

Flashcard 17: Identify the process by which water vapor cools and changes to liquid.

Answer: Condensation. Water vapor loses heat and transitions to liquid droplets.

Flashcard 18: What is the primary method by which groundwater returns to the surface?

Answer: Springs. Groundwater emerges naturally where water table meets surface.

Flashcard 19: What is the process of water soaking into the ground called?

Answer: Infiltration. Water penetrates soil surface and moves into underground spaces.

Flashcard 20: Which process involves the transition of water from liquid to gas at the surface?

Answer: Evaporation. Liquid water gains energy and becomes water vapor gas.

Flashcard 21: Identify the term for water that collects in large bodies like lakes and oceans.

Answer: Surface water. Includes rivers, lakes, oceans, and other visible water bodies.

Flashcard 22: Which term refers to the underground layer of water-bearing rock?

Answer: Aquifer. Permeable rock formation that stores and transmits groundwater.

Flashcard 23: What is the phase change from solid directly to gas called?

Answer: Sublimation. Ice transforms directly to vapor without melting to liquid.

Flashcard 24: What is the term for the process of water moving from the surface to the subsurface?

Answer: Infiltration. Water penetrates ground surface and moves into soil layers.

Flashcard 25: Which term describes the total amount of water evaporated and transpired from a landscape?

Answer: Evapotranspiration. Combined water loss from soil surfaces and plant leaves.

Flashcard 26: What is the term for water returning to Earth's surface from the atmosphere?

Answer: Precipitation. Water falls as rain, snow, sleet, or hail from clouds.

Flashcard 27: Name the process where water vapor is released from ice or snow directly to the air.

Answer: Sublimation. Ice transitions directly to vapor without melting first.

Flashcard 28: Identify the process that involves water seeping through soil and rock layers.

Answer: Percolation. Water moves downward through porous soil and rock layers.

Flashcard 29: What term describes the downward movement of water through soil?

Answer: Percolation. Gravity pulls water deeper through soil pore spaces.

Flashcard 30: Which term refers to the sum of all forms of water movement back to the atmosphere?

Answer: Evapotranspiration. Combines evaporation from surfaces and transpiration from plants.

Flashcard 31: What is the main reservoir for water in the hydrologic cycle?

Answer: Oceans. Hold approximately 97% of Earth's total water supply.

Flashcard 32: Identify the process where liquid water is converted to water vapor.

Answer: Evaporation. Heat energy transforms liquid water molecules into gaseous state.

Flashcard 33: Which term describes the continuous circulation of water in the Earth-atmosphere system?

Answer: Hydrologic cycle. Water continuously moves between atmosphere, land, and oceans.

Flashcard 34: Identify the term for the area of land where all water drains into a common outlet.

Answer: Watershed. Drainage basin bounded by topographic divides or ridges.

Flashcard 35: What is the primary energy source driving the hydrologic cycle?

Answer: The Sun. Solar energy provides heat for evaporation and drives atmospheric circulation.

Flashcard 36: Name the process where precipitation is intercepted by vegetation before reaching the ground.

Answer: Interception. Plant canopies catch rainfall before it reaches soil surface.

Flashcard 37: Name the process by which water vapor forms into ice without becoming liquid first.

Answer: Deposition. Water vapor directly forms solid ice crystals without liquid stage.

Flashcard 38: What is the term for the solid form of precipitation that falls as ice crystals?

Answer: Snow. Frozen precipitation formed from ice crystals in clouds.

Flashcard 39: Identify the form of precipitation that occurs when rain freezes before hitting the ground.

Answer: Sleet. Rain freezes into ice pellets during descent through cold air.

Flashcard 40: Name the process by which rainfall is absorbed by soil and stored as groundwater.

Answer: Recharge. Replenishment of groundwater through infiltration and percolation.

Flashcard 41: Identify the term for the area of land where all water drains into a common outlet.

Answer: Watershed. Drainage basin bounded by topographic divides or ridges.

Flashcard 42: Which process is responsible for the formation of clouds?

Answer: Condensation. Water vapor cools and forms tiny droplets around particles.

Flashcard 43: What term describes the loss of water from plants to the atmosphere?

Answer: Transpiration. Water exits plant leaves through stomatal pores as vapor.

Flashcard 44: Which term refers to the water present beneath Earth's surface in soil pore spaces?

Answer: Groundwater. Water stored in underground soil and rock spaces.

Flashcard 45: Identify the process where water moves from saturated ground to bodies of water.

Answer: Baseflow. Groundwater slowly flows into streams and rivers continuously.

Flashcard 46: What is the primary method by which groundwater returns to the surface?

Answer: Springs. Groundwater emerges naturally where water table meets surface.

Flashcard 47: Identify the process by which water vapor cools and changes to liquid.

Answer: Condensation. Water vapor loses heat and transitions to liquid droplets.

Flashcard 48: What is the process where plants absorb water through roots and release it as vapor?

Answer: Transpiration. Water moves from roots to leaves and exits as vapor.

Flashcard 49: Identify the process where water moves from saturated ground to bodies of water.

Answer: Baseflow. Groundwater slowly flows into streams and rivers continuously.

Flashcard 50: Name the process where water vapor forms liquid droplets in the atmosphere.

Answer: Condensation. Phase change from gas to liquid when air cools.

Flashcard 51: What term describes the movement of water from plant leaves to the atmosphere?

Answer: Transpiration. Plants release water vapor through leaf pores called stomata.

Flashcard 52: What is the process where plants absorb water through roots and release it as vapor?

Answer: Transpiration. Water moves from roots to leaves and exits as vapor.

Flashcard 53: Name the process where precipitation is intercepted by vegetation before reaching the ground.

Answer: Interception. Plant canopies catch rainfall before it reaches soil surface.

Flashcard 54: Identify the process where liquid water is converted to water vapor.

Answer: Evaporation. Heat energy transforms liquid water molecules into gaseous state.

Flashcard 55: What is the phase change from solid directly to gas called?

Answer: Sublimation. Ice transforms directly to vapor without melting to liquid.

Flashcard 56: Which term describes the total amount of water evaporated and transpired from a landscape?

Answer: Evapotranspiration. Combined water loss from soil surfaces and plant leaves.

Flashcard 57: Which term describes the continuous circulation of water in the Earth-atmosphere system?

Answer: Hydrologic cycle. Water continuously moves between atmosphere, land, and oceans.

Flashcard 58: Name the process where water vapor is released from ice or snow directly to the air.

Answer: Sublimation. Ice transitions directly to vapor without melting first.

Flashcard 59: Which process is responsible for the formation of clouds?

Answer: Condensation. Water vapor cools and forms tiny droplets around particles.

Flashcard 60: Which component of the hydrologic cycle involves water moving across the Earth's surface?

Answer: Surface runoff. Water flows over land when infiltration capacity is exceeded.

Flashcard 61: Identify the phase change from ice directly to water vapor.

Answer: Sublimation. Solid water transforms directly to gas without liquid phase.

Flashcard 62: What is the largest source of freshwater on Earth?

Answer: Glaciers and ice caps. Store about 68% of world's freshwater in frozen form.

Flashcard 63: What is the primary energy source driving the hydrologic cycle?

Answer: The Sun. Solar energy provides heat for evaporation and drives atmospheric circulation.

Flashcard 64: Name the process by which water vapor forms into ice without becoming liquid first.

Answer: Deposition. Water vapor directly forms solid ice crystals without liquid stage.

Flashcard 65: What is the term for the solid form of precipitation that falls as ice crystals?

Answer: Snow. Frozen precipitation formed from ice crystals in clouds.

Flashcard 66: What is the term for water flowing over the land surface into bodies of water?

Answer: Runoff. Surface water flows due to gravity when soil cannot absorb more.

Flashcard 67: What term describes the movement of water from plant leaves to the atmosphere?

Answer: Transpiration. Plants release water vapor through leaf pores called stomata.

Flashcard 68: What is the largest source of freshwater on Earth?

Answer: Glaciers and ice caps. Store about 68% of world's freshwater in frozen form.

Flashcard 69: Identify the form of precipitation that occurs when rain freezes before hitting the ground.

Answer: Sleet. Rain freezes into ice pellets during descent through cold air.

Flashcard 70: What is the main reservoir for water in the hydrologic cycle?

Answer: Oceans. Hold approximately 97% of Earth's total water supply.

Flashcard 71: What process accounts for the majority of water vapor in the atmosphere?

Answer: Evaporation. Ocean surface evaporation contributes most atmospheric water vapor.

Flashcard 72: Which term refers to the sum of all forms of water movement back to the atmosphere?

Answer: Evapotranspiration. Combines evaporation from surfaces and transpiration from plants.

Flashcard 73: Name the process by which rainfall is absorbed by soil and stored as groundwater.

Answer: Recharge. Replenishment of groundwater through infiltration and percolation.

Flashcard 74: What is the term for the process of water moving from the surface to the subsurface?

Answer: Infiltration. Water penetrates ground surface and moves into soil layers.

Flashcard 75: Identify the phase change from ice directly to water vapor.

Answer: Sublimation. Solid water transforms directly to gas without liquid phase.

Flashcard 76: What is the process called when water is absorbed by soil and moves underground?

Answer: Infiltration. Water enters soil and becomes part of groundwater system.

Flashcard 77: Name the process where water vapor forms liquid droplets in the atmosphere.

Answer: Condensation. Phase change from gas to liquid when air cools.

Flashcard 78: Identify the process that involves water seeping through soil and rock layers.

Answer: Percolation. Water moves downward through porous soil and rock layers.