Unit 13 Earth's Fresh Water Flashcards

Questions and Answers

What is freshwater?

Freshwater is water that contains little or no dissolved salt.

Where is most of Earth's freshwater found?

Most freshwater is found frozen in ice caps and glaciers.

What process changes water from a liquid to a gas? From a gas to a liquid?

The Water Cycle is the process that changes water from a liquid to a gas, and from a gas to a liquid.

Define infiltration and runoff.

Runoff is precipitation that flows over the surface of the land; infiltration is the process by which water soaks into the ground. Signup and view all the answers

Describe the substance known as water.

Water is a simple chemical compound with the chemical formula H2O, consisting of two hydrogen atoms and one oxygen atom. Signup and view all the answers

Why does most precipitation fall into the oceans?

Most precipitation falls into the oceans because water takes up 71% of the Earth. Signup and view all the answers

What are the source and mouth of a river?

The source of a river is where it starts; the mouth is where it ends. Signup and view all the answers

Define tributary and river system.

Tributaries are small streams that flow into bigger streams or rivers; a river system includes a river and all its tributaries. Signup and view all the answers

How may water enter a pond or lake?

Water enters a pond or lake when it travels downhill, filling a depression in the ground. Signup and view all the answers

What is a wetland?

A wetland is an area that is covered with water or has very soggy soil during all or part of the year. Signup and view all the answers

List three reasons why wetlands should be protected.

<ol> <li>Wetlands have great biodiversity. 2) They purify water. 3) They slow rushing water during extreme weather.</li> </ol> Signup and view all the answers

Define groundwater.

Freshwater below the Earth's surface is called groundwater. Signup and view all the answers

Describe how water enters the ground.

Water seeps down into the ground through porous rocks and soil until it reaches an impermeable rock. Signup and view all the answers

What is the water table? What might cause it to rise or fall?

The top of the saturated rock layer is called the water table; it rises with rain and falls during dry weather. Signup and view all the answers

Define aquifer. Where does an aquifer get its water?

An aquifer is an underground layer of rock saturated with groundwater; it gets water from surface infiltration. Signup and view all the answers

What is the purpose of a well?

The purpose of a well is to provide a good supply of water. Signup and view all the answers

Study Notes

Freshwater Overview

Freshwater contains minimal to no dissolved salts, distinguishing it from saline water bodies.
Ice caps and glaciers hold the majority of Earth's freshwater, emphasizing the significance of polar regions in the global water supply.

Water Cycle

The Water Cycle facilitates the transition of water from liquid to gas (evaporation) and from gas to liquid (condensation), critical for maintaining environmental balance.

Water Movement

Runoff refers to precipitation that flows over land, potentially transporting pollutants to water bodies, leading to water contamination.
Infiltration is the process by which water permeates the ground, replenishing soil moisture and groundwater supplies needed for plant growth.

Chemical Composition of Water

Water is chemically represented as H2O, consisting of two hydrogen atoms bonded to one oxygen atom, highlighting its simple yet essential molecular structure.

Precipitation Patterns

Oceans receive the majority of precipitation due to covering 71% of Earth's surface, affecting rain distribution and runoff to other water bodies.

River Systems

A river's source marks its beginning, while the mouth indicates where it flows into a larger body of water.
Tributaries are smaller streams feeding into larger rivers, forming a comprehensive river system when combined.

Ponds and Lakes

Ponds and lakes form when downhill-moving water collects in depressions after precipitation, illustrating natural water accumulation processes.

Wetlands Importance

Wetlands sustain biodiversity by serving as habitats for numerous species, many of which face endangerment due to habitat loss.
They act as natural water purifiers, filtering sediments and toxins to protect larger aquatic ecosystems.
Wetlands play a crucial role in flood mitigation by absorbing excess water during heavy rainfall and storms.

Groundwater Basics

Groundwater resides below the Earth's surface, stored in aquifers and played a pivotal role in terrestrial ecosystems.
Water enters the ground via seeping through porous materials until it hits impermeable rock, regulating groundwater levels.

Water Table Dynamics

The water table represents the upper boundary of saturated ground, fluctuating based on surface water infiltration, rainfall, and climatic conditions, rising after heavy rain and lowering during droughts.

Aquifers and Recharge

Aquifers are underground rock layers saturated with groundwater, often located in porous materials like sandstone, essential for human water supply.
Water replenishes aquifers via recharge, where surface water seeps into the ground.

Wells and Water Supply

Wells are constructed to access groundwater, providing a reliable water source for communities, showcasing the importance of underground water resources throughout history.

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Description

Test your knowledge on freshwater concepts with these flashcards from Unit 13. Explore definitions, sources, and the Water Cycle. Perfect for reinforcing your understanding of Earth's freshwater resources.