Lecture 10 - Chapter 11

Question 1

Water may seem abundant, but drinkable water is rare, true or false?

Answer 1

This true.

Question 2

What is Freshwater?

Answer 2

Is relatively pure, with few dissolved salts
– Only 2.5% of Earth’s water is fresh, most is tie up in glaciers and ice caps

Question 3

How does Water Moves Through the Hydrologic Cycle?

Answer 3

Water is constantly moving among the reservoirs via the hydrologic cycle:
• As water moves through the hydrologic cycle:
– stores and distributes heat
– erodes mountain ranges
– builds river deltas
– maintains ecosystems
– supports civilization
– gives rise to political conflicts

Question 4

What is Residence times?

Answer 4

It storage time for water
• Reservoirs differ in resident times and amount of water they store

Question 5

How much Water Supplies Our Households, Agriculture, and Industry?

Answer 5

Globally we use about 70% of annual freshwater allotment on agriculture:
- 5% is for cleaning
- 10% cooking, and drinking
- 20% laundry
- 30% Toilet flushing
- 35% showers and bath

Question 6

Why is Water in situ Is Important for Both People
and Ecosystems?

Answer 6

• Water is critically important as a resource for human life and activities

• Water holds immense value in situ (“in place”)

• Freshwater systems are important for ecosystem services
– Both direct and indirect benefits

Question 7

How Climate Change Will Cause Changes in the
Hydrologic Cycle?

Answer 7

• Climate change will affect the hydrologic cycle:
– shift northward in mid-latitude rain belt
– earlier snowmelt and spring runoff
– more evapotranspiration
– drier summers in the interior continental region

• Additional impacts:
– warmer rivers (impacting fish) – thermal pollution
– lower water levels in Great Lakes
– higher ocean water levels

Question 8

What are freshwater systems?

Answer 8

Water from rain, snowmelt, or springs forms
streams, creeks, or brooks

Question 9

What merge into rivers, and eventually
reaches the ocean?

Answer 9

– Tributary = a smaller river slowing into a
larger one
– Drainage basin or watershed = the area of land drained by a river and its tributaries

Question 10

If there is a large bend in the river, the force of the water cuts through the land by _________

Answer 10

– Oxbow = an extreme bend in a river
– Oxbow lake = the bend is cut off and remains as an isolated, U-shaped body of water

Question 11

What is Floodplain?

Answer 11

areas nearest to the river’s course that are
flooded periodically
– Frequent deposition of silt makes floodplain soils fertile

Question 12

What is Riparian?

Answer 12

riverside areas that are productive and species-rich

Question 13

Water of rivers and streams hosts diverse ecological communities true or false?

Answer 13

True

Question 14

How are Wetlands Are Diverse and Complex? What are the different wetlands?

Answer 14

• Wetlands
• Freshwater marshes
• Swamps
• Bogs

Question 15

Wetlands Are Diverse and Complex, what are wetlands?

Answer 15

Are systems that combine elements of freshwater
and dry land

Question 16

Wetlands Are Diverse and Complex, what are Freshwater marshes?

Answer 16

shallow water allows plants to grow above the water’s surface

Question 17

Wetlands Are Diverse and Complex, what are Swamps?

Answer 17

shallow water that occurs in forested areas
– Can be created by beavers

Question 18

Wetlands Are Diverse and Complex, what are Bogs?

Answer 18

Are ponds covered in thick floating mats of vegetation
– A stage in aquatic succession

Question 19

What are wetlands for wildlife?

Answer 19

• Wetlands are extremely valuable for wildlife
• They:
– slow runoff
– reduce flooding
– recharge aquifers
– filter pollutants
• People have drained wetlands, mostly for
agriculture
– Southeastern (Potholes region) Canada
has lost more than half of their wetlands

Question 20

What are lakes and How does Lakes Contain Open, Standing Water?

Answer 20

They have:
• Lakes and ponds are bodies of open, standing water
• Littoral zone
• Benthic zone
• Limnetic zone
• Profundal zone

Question 21

Lakes Contain Open, Standing Water, what is Littoral zone?

Answer 21

Is the region ringing the edge of a water body

Question 22

Lakes Contain Open, Standing Water, what is Benthic zone?

Answer 22

Extends along the entire bottom of the
water body
– home to many invertebrates

Question 23

Lakes Contain Open, Standing Water, what is Limnetic zone?

Answer 23

open portions of the lake or pond where
the sunlight penetrates the shallow waters

Question 24

Lakes Contain Open, Standing Water, what is Profundal zone?

Answer 24

water that sunlight does not reach
– supports fewer animals because there is less oxygen