Lessons on the Lake logo Natural Forces Affecting the Basin subsidence and erosion in the basin
thinking at right angles linking lake factors hurricanes activity: subsidence and erosion activity: c-mail the pontchartrain picayune multimedia presentation help! i'm up to my hips in water!
chapter 8 introduction essential questions global climate change are sea levels rising?
Lessons on the Lake -> Chapter 8 -> Subsidence/ Erosion

ACTIVITY: Subsidence/Erosion:
What Can We Do?

As you’ve learned, subsidence and erosion are serious problems in the Lake Pontchartrain Basin. It is taking concerted effort on the part of a number of governmental agencies and citizens groups to combat these forces. Complete the following problem/solution outlines on these issues. The first one has been started for you!


What: Land subsidence

Why: levees, compaction of sediments, extraction
of groundwater and minerals, urbanization,
wetland drainage and development

Attempted Solutions



Add 'fill' to landscape

temporary; fill washes away easily


cut 'crevasses' in levee

sediment accumulates; builds land


plant vegetation

holds sediment in place


keep more 'green space'

allows water to infiltrate ground


End result?

During winter months, much of the heron's diet comes from small land mammal like mice and voles.
  1. Introduction
  2. Essential Questions
  3. Global Climate Change
  4. Are Sea Levels Rising?
  5. Subsidence and Erosion in the Basin
  6. Activity: Thinking at Right Angles
  7. Activity: Linking Lake Factors
  8. Hurricanes
  9. Activity: Subsidence and Erosion
  10. Activity: C-Mail
  11. Activity: The Pontchartrain Picayune
  12. Activity: Multimedia Presentation
  13. Activity: Help! I'm Up to my Hips in Water!