Exam #3 Study Notes Topic 8: Water Resources

A collection of flashcards reviewing key vocabulary and concepts related to water resources and the hydrologic cycle, preparing students for their upcoming exam.

Hydrologic Cycle

The circulation of water through the atmosphere, hydrosphere, lithosphere, and biosphere via evaporation and precipitation.

Ocean Water

Over 97% of Earth's water is found in the oceans, which cover more than 70% of the planet.

Atmospheric Water Vapor

Water vapor present in the atmosphere, which can be measured in millimeters (mm).

Precipitation (P)

The amount of water falling from the atmosphere to the Earth, exceeding evaporation and transpiration over land.

Evaporation (E)

The process by which water changes from a liquid to a gas, generally exceeding precipitation over bodies of water.

Transpiration (T)

The process by which plants release water vapor into the air.

Evapotranspiration

The sum of evaporation and transpiration, representing the actual water loss from the surface.

Actual Evapotranspiration (ACTET)

The actual water evaporation from open water, soil, and plant surfaces.

Potential Evapotranspiration (POTET)

The maximum potential amount of water that can evaporate/transpire under optimal conditions.

Moisture Balance of the Atmosphere

The balance of moisture entering (inputs) and exiting (outputs) the atmosphere.

Input of Evaporation

Evaporation from oceans which constitutes 86% of atmospheric moisture input.

Output of Precipitation

The percentage of water falling as precipitation from oceans (78%) and land (22%).

Groundwater Resources

The largest potential freshwater source, accounting for over 22% of global freshwater.

Aquifers

Subsurface layers of permeable rock or materials that allow groundwater flow and storage.

Drought Conditions

Characterized by less precipitation than needed compared to climate normals.

Types of Drought

Includes meteorological, agricultural, hydrological, and socioeconomic droughts.

Groundwater Flow Model

Visual representation of interactions between deep and shallow wells, root zones, and zones of soil moisture.

Water Budget at the Surface

The accounting of inputs (precipitation) and expenditures of water at the Earth's surface.

Infiltration and Percolation

Processes involving the movement of water through soil layers into groundwater.

Field Capacity

The maximum amount of water the soil can hold after excess has drained away.

Wilting Point

The point at which water is no longer available for plant use.

Mean Annual Precipitation

The average yearly precipitation amount measured in millimeters across global regions.

Climate Normals

Long-term averages of climatic variables used for comparison over time.

Water Withdrawal by Sector

The estimated total annual water withdrawals by various regions for different uses.

Groundwater Scarcity

The ranking of groundwater availability from extremely high to low.

Global Water Stress Projection (2050)

Classifies water stress levels indicating future challenges in water availability across regions.

Weather vs. Climate

Weather refers to short-term atmospheric conditions while climate represents long-term averages.

Global Climate Classifications

Five regions based on temperature and precipitation: Tropical, Mesothermal, Microthermal, Polar, and Desert.

Tropical Rainforest

A biome characterized by high mean precipitation (2971 mm) and consistent warm temperatures.

Polar Climates

Characteristics include extremely cold conditions and seasonal changes that lack true summer.

Desert Climates

Regions with high potential evapotranspiration exceeding precipitation, leading to a constant water deficit.

Primary Succession

The development of a biological community in an area devoid of soil and life.

Secondary Succession

The re-establishment of a community following a disturbance where soil and organisms remain.

Food Chain

A linear sequence of organisms where energy is transferred from producers to consumers.

Photosynthesis Equation

The process by which plants convert carbon dioxide and water into glucose and oxygen.

Normalized Difference Vegetation Index (NDVI)

An index that assesses vegetation density in a given area.

Net Primary Productivity (NPP)

The amount of organic material produced by photosynthetic organisms in an ecosystem per unit area.

Vegetation Patterns

The distribution and types of plant communities across various environmental conditions.

Biomes

Large terrestrial regions defined by distinct plant and animal communities related to climate.