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Mountains to Atolls

Run the Mountains to Atolls MicroSim Fullscreen

About This MicroSim

Nepal, Bhutan and the Maldives sit at opposite ends of South Asia's "staircase." This MicroSim draws a schematic elevation profile that starts at a low coral atoll in the Maldives (average ground about 1.5 m, highest natural point about 2.4 m), crosses the Indian Ocean, and climbs through Nepal's Terai plains (about 67 to 300 m), Kathmandu (about 1,400 m) and Bhutan's capital Thimphu (about 2,250 to 2,650 m) to the summit of Mount Everest (8,848.86 m, 2020 China-Nepal survey). The places are lined up as steps on one staircase, and horizontal distances are not to scale.

The sea-level slider raises the ocean by up to 2 m. On the mountain-scale panel, the sea line barely moves (the sim reports how many pixels). In the close-up below, a sample atoll island, shaped from the Maldives' average and highest elevations, floods as the sea rises, and the sim reports how much of the island's width lies below the new sea level. Optional bands show the IPCC's likely global sea-level rise by 2100: 0.28 to 0.55 m with very low emissions and 0.63 to 1.01 m with very high emissions (IPCC AR6, 2021).

The island is schematic, so its percentages are not a forecast for any real island. No borders are drawn.

How to Use

  1. Click or tap each marker on the top panel, or pick a place from the menu, and read its elevation and a short description.
  2. Notice the axis: the top panel runs from 0 to about 9,000 m.
  3. Drag the Sea-level rise slider to 1.00 m. Watch the top panel and read how many pixels the sea line moved.
  4. Now look at the close-up. Read how much of the sample island is below the new sea level.
  5. Keep Show IPCC 2100 ranges ticked and compare the green (very low emissions) and orange (very high emissions) bands with the island's shape.
  6. Try 2.00 m, a rise scientists cannot rule out under very high emissions but consider unlikely by 2100.

Learning Objective

Students will be able to compare how altitude and sea level shape life in Nepal, Bhutan and the Maldives by reading a schematic elevation profile and testing how a given sea-level rise affects a low atoll island.

Bloom level: Analyze (compare, explain).

Iframe Embed Code

<iframe src="https://aaryavvatts-lab.github.io/south-asian-culture-textbook/sims/ch20-mountains-to-atolls/main.html" height="792px" width="100%" scrolling="no"></iframe>

Lesson Plan

Grade level: 9 to 12 (world geography, environmental science, world history, ethnic studies, or a South Asian student club meeting)

Duration: 15 to 20 minutes

Activity:

  1. (3 min) Before opening the sim, students guess how many times taller Everest is than the Maldives' highest natural ground.
  2. (5 min) Students tap all six places and record each elevation in a table. They check their guess (about 3,700 times).
  3. (5 min) Students set the slider to 0.55 m, 1.01 m and 2.00 m and record the pixel shift on the top panel and the share of the sample island below sea level.
  4. (5 min) Pairs discuss: Why does a rise that is invisible from Kathmandu matter so much in Malé? What climate worry do Nepal and Bhutan face instead?

Assessment questions:

  1. Which place on the profile is highest, and what is its elevation? Which is lowest?
  2. About how high is the Maldives' highest natural ground, and how does that compare with the IPCC's likely range for sea-level rise by 2100?
  3. Why does the sea line on the top panel barely move, even at 2 m?
  4. Name one way that rising seas threaten an atoll island besides covering it with water.
  5. Compare one climate risk for Nepal or Bhutan with one for the Maldives.

Chapter 20: Nepal, Bhutan, and the Maldives