1 of 38

Soil Lab:

2 of 38

Lime = calcium carbonate

  • Improves calcium availability and increases the pH (makes it more alkaline)

3 of 38

Add Organic Matter (Compost):

  • Adding organic materials improves the ability of sandy soils to hold nutrients and water.
  • For clay soil, organic additions improve drainage and aeration and help the soil dry out and warm up more quickly in the spring.
  • Add inorganics like sand and perlite to increase porosity.

4 of 38

Sand:

  1. high porosity and high permeability → water will drain very quickly making it unavailable to plant roots!
  2. Readily leaches nutrients. Deserts have lower levels of organic materials (compost) so nutrients may be limited

5 of 38

Aeration = puncturing holes into the soil to reduce compaction and allow water, nutrient and air penetration

Compaction = compressed soil (from tractors, people walking, wildlife)

6 of 38

Soil needs to be able to hold some water, but not so much that plant roots can’t breathe. A loam achieves that balance.

Clay gets a bad rap because too much of it means it holds lots of water and the soil stays wetter, colder and is difficult to work.

clay is where the nutrients in soil are stored. "Sand and silt don't store nutrients; they're just rocks.”*

*https://extension.oregonstate.edu/news/sand-silt-or-clay-texture-says-lot-about-soil-0

7 of 38

Clay! Low porosity and permeability.

8 of 38

Atmospheric Circulation Lab

9 of 38

Topic 4.7 Solar Radiation and Earth’s Seasons

LO: Explain how the sun’s energy affects the Earth’s surface

10 of 38

Insolation:

Incoming solar radiation.

It is the main source of energy on Earth.

It depends on season and latitude.

Insolation = solar radiation

area

11 of 38

Latitude:

The angle of the sun’s rays determines the intensity.

The latitude that is directly horizontal (angle of insolation is 90 degrees) to the solar radiation receives the most intensity.

12 of 38

Highest Insolation:

Over the duration of the year, the highest insolation is at or near the equator and decreases toward the poles.

13 of 38

Seasonal Insolation:

The solar radiation received at a location varies seasonally. The highest insolation occurs on the longest summer day of the year at that location.

14 of 38

23.5 Degree Tilt of Earth:

Earth rotates at a 23.5 degree tilt. This causes the seasons and changes the number of hours of daylight.

15 of 38

16 of 38

Topic 4.6 Watersheds

Learning Objective: Describe the characteristics of a watershed.

17 of 38

Watershed:

Area that drains water to the same location.

  • Surface water (lakes, rivers) and groundwater

Ridges/hills that separate two watersheds = drainage divide/ watershed boundary.

18 of 38

Rainwater runs off or infiltrates the soil to join groundwater.

19 of 38

20 of 38

Characteristics

Soil: Clay and rocky soils absorb water slower than sand→ more runoff. Floodplains are fertile.

21 of 38

Characteristics

Vegetation: Forests soils have high permeability and absorb precipitation. Vegetation upstream impacts water quality downstream.

22 of 38

Characteristics

Surface water and stormwater runoff: Drains downstream. The rate depends on slope and surface type. Steeper slopes → erosion. Impervious surfaces don’t allow infiltration (parking lots, roads) which drain directly into streams → more flooding. Land use upstream determines water quality downstream. E.g logging upstream will increase turbidity downstream.

23 of 38

24 of 38

Characteristics

Divides with adjoining watersheds:

Where one watershed begins and

ends. It is important to know where water pollutants will drain into.

25 of 38

Characteristics?

  • Area
  • Vegetation and soil
  • Slope

26 of 38

Characteristics?

  • Area
  • Vegetation and soil
  • Slope

27 of 38

Characteristics?

  • Area
  • Vegetation and soil
  • Slope

28 of 38

Major Types of Human impact on Watersheds:

29 of 38

Human impact

Water Diversion: For cities and agriculture

Paved surfaces: Waste from cars flows into streams, more runoff, more flooding

Runoff pollutants: Fertilizer, pesticides, animal waste, human waste, chemicals

30 of 38

Solutions

Water diversion: Collect rainwater, more efficient irrigation, $ for farmers to avoid planting water intensive crops (dry farming), water use limits

Paved surfaces: Permeable pavement, green spaces

Runoff: Buffer zone of vegetation

before runoff reaches surface water,

barriers to runoff (straw bales. booms)

31 of 38

32 of 38

Sustainable Drainage Systems: https://www.youtube.com/watch?v=LMq6FYiF1mo

33 of 38

34 of 38

Colorado River Basin Case Study

35 of 38

Areas within and outside the watershed that receive river water.

36 of 38

37 of 38

Discuss the following questions:

  • What are some of the largest users of the Colorado River?
  • What are some of the biggest drivers of the current water shortage in the Colorado River basin?
  • How much money is the Colorado River worth to the economy?
  • How could we solve some of these water shortage issues?
  • Brainstorm: What are the environmental outcomes of how we manage the river?

38 of 38