Nepal's Three Worlds

सिकाइ उद्देश्यहरू

• Calculate approximate altitude from barometric pressure using the barometric formula.
• Describe the key differences in climate between Nepal's terai, hills and mountain zones.
• Explain why altitude causes temperature to decrease (environmental lapse rate).
• Predict what sensor readings would look like at a different altitude from the current station.

पृष्ठभूमि

Barometric pressure decreases predictably with altitude because there is less atmosphere above you as you ascend. At sea level, the full weight of the atmosphere presses down at about 1013 hPa. At 1,400 m (approximately Kathmandu's altitude), pressure is around 856 hPa. At Everest Base Camp (5,364 m), it is about 510 hPa. The barometric formula altitude = 44,330 × (1 − (P / 1013.25)^0.1903) gives a reasonable estimate from a pressure reading alone — the HICS dashboard calculates this for you.

Temperature decreases with altitude at approximately 6.5°C per 1,000 metres — the environmental lapse rate. This is why the Himalaya have permanent snow while the terai at the same latitude is subtropical. The lapse rate also explains why Nepal's hill towns are pleasant in summer while Kathmandu valley can be hot, and why Nepal's mountain communities face extreme cold that terai communities never experience.

Nepal's three ecological zones each have distinct biodiversity and land use. The terai's Sal forests and grasslands support Bengal tigers and one-horned rhinos. The mid-hills' terraced agriculture — Nepal's most iconic landscape — produces rice, wheat, millet and vegetables. The high mountains, above the treeline, support yak herding and high-altitude crops like buckwheat and barley.

विधि

1. Read the current pressure from the dashboard: ___ hPa. Use the formula altitude = 44,330 × (1 − (P ÷ 1013.25)^0.1903) to calculate the station's altitude. Compare with a map.
2. Use the environmental lapse rate (6.5°C per 1,000 m) to estimate what the temperature would be 1,000 m higher. Then estimate 2,000 m higher. Show your working.
3. Make a table: terai, hills, mountains. Fill in: typical altitude range, typical temperature range, typical annual rainfall, main crops/vegetation, key biodiversity.
4. Predict: if this station were in Jumla (2,300 m) rather than your current location, what values would you expect for temperature, pressure and humidity? Explain your reasoning.
5. Climate change question: which zone is warming fastest? (Answer: high mountains — do your own research and present a one-paragraph explanation.)

छलफल प्रश्नहरू

1. A family lives at 3,500 metres. How does altitude affect their daily life, work and health compared to a family at 500 metres?
2. Nepal's glaciers are retreating. What happens to rivers and agriculture downstream as glaciers shrink?
3. Why does Nepal have such high biodiversity in a relatively small area?

कार्यपत्र

शब्दावली

Environmental Lapse Rate

The rate at which temperature decreases with altitude in the atmosphere — approximately 6.5°C per 1,000 metres.

Barometric Formula

A mathematical relationship between atmospheric pressure and altitude, derived from the physics of the atmosphere.

Ecological Zone

A geographic area with a characteristic climate, vegetation type and biodiversity, distinct from adjacent areas.

Biodiversity

The variety of living organisms in an area — including species diversity, genetic diversity and ecosystem diversity.

विस्तार

Research Nepal's Koshi River system from its source in the Himalaya to its outflow into the Ganges. Draw a cross-section showing how altitude, temperature and rainfall change along its length. Annotate with the communities, agriculture and biodiversity associated with each zone.