Terraces · Bamboo ValleyScience for kids

Why do people build terraces on hillsides?

In short: Terraces are level steps cut into a hillside. They slow rainwater so it soaks in instead of rushing down, which keeps soil from washing away and makes farming easier. But their walls and drains need regular care, or they can collapse.

How it works

When rain falls on a bare, steep slope, it races downhill and carries the rich topsoil with it. Turn the slope into a series of flat steps and the water slows down at each level, or even stops and soaks into the ground, so the soil stays put.

Terraces work like a staircase: a steep wall is hard to climb, but small steps are easy. Rice terraces also hold water like a row of shallow pools, letting it trickle from one level to the next so every field from top to bottom gets watered.

Terraces have a weak spot. If drains get blocked, water builds up in the fields or seeps into the walls, which can loosen them and even cause a slip. That is why farmers keep repairing walls and clearing ditches, and abandoned terraces slowly fall apart.

Where to see it in New Zealand

Māori built terraces too. On Auckland's volcanic cones, such as Maungawhau / Mount Eden and Maungakiekie / One Tree Hill, you can still see step-like terraces left from old pā, or fortified villages. People built houses on them and dug pits to store kūmara.

Try it together

Outside, fill two shallow trays with damp soil. Smooth one into a plain slope and shape the other into a few small steps, then tilt both trays. Sprinkle water slowly from a watering can and see which tray loses more soil.

Kids also ask

Are terraces only for rice?

No. Terraces are also used for tea, maize, potatoes, grapes and other crops. Rice terraces are built to hold water, while terraces for dry crops focus more on letting extra water drain away safely.

Do terraces stop landslides completely?

No. They slow runoff and reduce erosion, but if drainage is poor, rain is very heavy or walls are not looked after, terraces can collapse too. Good drainage matters as much as the steps.

Where are some famous terraces?

The Hani rice terraces in Yunnan, China, and the rice terraces of the Philippine Cordilleras are both World Heritage sites. The Inca also built many terraces in the Andes mountains of South America.

In the game, “Terraces” is a nature card on Bamboo Valley.

Your child finds this card by reaching the right place or meeting the right weather on the island, and lights it up by answering the question on the back. Tap the button below and the game shows your child which island it is on and how to find it. Mochi Isle is a browser learning game for ages 5 to 18; the main island and the daily lesson are free.

Find “Terraces” on the island ↗ All cards from Bamboo Valley