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Relief of a Country: Mountains, Plateaus, Plains and Delta

Relief means the ups and downs of the land. A country's relief is usually arranged in belts: high mountains, then hills and plateaus, then low plains, and at the end a river delta or the sea. The belts are linked by height, by rock type and by how they formed. Romania is a clear example: the Carpathian arc, the Transylvanian basin inside it, hills and plateaus around it, the Romanian Plain in the south and the Danube Delta by the Black Sea.

🎬 Step-by-step story

  1. Start with a flat slab of land. Nothing is raised. Relief means the ups and downs, so this land has none yet.
  2. Now the mountains rise in a curved arc along the north. This is the highest belt. It is the backbone of the country.
  3. Inside the arc sits a basin, a high bowl ringed by mountains. Outside the arc, a belt of low hills grows. The hills are the foothills.
  4. In the east a plateau rises. It is high like a hill but its top is flat, cut by river valleys.
  5. The south slopes down to a wide plain. The river carries mud to the sea and builds a delta. The blue water is the sea.
  6. Free play: slide the walker from the mountains to the sea. The text tells you the landform and the height. Where does the height first fall below 100 m?

Tip: drag the 3D scene to turn it. Use two fingers to zoom.

🤔 Common doubts, cleared

What exactly is relief?

Relief is how high or low the land is. A flat slab has no relief; each raised block you see later adds relief.

Why are the mountains in an arc and not a straight line?

Mountains rise where the crust is squeezed, and the squeeze can bend the belt. Romania's Carpathians curve like a horseshoe. See the arc rise in step 1.

Is a basin the same as a plain?

No. A basin is a bowl ringed by higher land and can itself be hilly and high. A plain is low and flat. Compare step 2 with step 4.

How is a plateau different from a hill?

A plateau is broad with a flat top; a hill is small with a rounded top. Look at the flat top of the eastern block in step 3.

Why is the land near the sea so low?

Rivers drop mud there and build flat land. The south slopes down to the plain, the delta and the sea in step 4.

How do I read the height from the walker?

Move the slider. The sentence below the model tells you the landform and the height above sea level in metres.

Overall layout of relief

Relief is the shape of the land surface: high places, low places and the slopes between them. A map can show it with colours (green for low, brown for high) or with contour lines.

The main relief forms are:

In many countries these forms come in belts, one next to the other, as you saw in the 3D. In Romania, the mountains, hills and plateaus and plains each cover roughly one third of the land.

Mountains and basins: the Carpathian arc and Transylvania

The Carpathians bend like a big arc through the middle of the country. They have three parts: the Eastern, Southern and Western Carpathians. Moldoveanu Peak (2,544 m) in the Southern Carpathians is the highest point of Romania.

Inside the arc lies the Transylvanian Depression. It is a basin about 300 to 600 m high, ringed by mountains. Its floor is hilly, not flat, and rivers like the Mureş and Someş drain it. Compare it with the 3D: the basin is lower than the mountain ring but higher than the plain.

Hills and plateaus

Outside the mountain arc there is a belt of lower land. The Subcarpathians are hills at the foot of the Carpathians. They have salt, oil and orchards. The Getic Plateau and the Mehedinţi Plateau lie south and south-west of the Southern Carpathians. The Moldavian Plateau in the east is cut by rivers and slopes gently. The Dobruja Plateau in the south-east is very old and low; the worn-down Măcin mountains rise above it, below 500 m. The Western Hills are small hills at the foot of the Apuseni mountains, and beyond them lies the Western Plain along the Tisa side.

Plateau or hill? A plateau has a flat top, a hill has a rounded top.

Plains, the delta and the shelf

The Romanian Plain in the south is a wide, low plain along the Danube. It is covered with fertile river mud, so it is the main farmland. The Western Plain is similar and lies along the western side.

Where the Danube meets the Black Sea it slows down and drops its mud. Over thousands of years the mud has built the Danube Delta: a low, wet, young land of channels, reeds and lakes, only a few metres above the sea. It is still growing every year.

Under the sea the land continues as the continental shelf: a shallow, gently sloping sea floor up to about 200 m deep. After that the slope drops steeply into the deep sea.

Try it: read a relief profile

In the 3D, go to the last step. Drag the Walk slider slowly. After each move, read the sentence under the model and write down the landform and the height. Then do the maths: temperature falls about 0.65 °C for every 100 m you climb. If it is 20 °C at the plain, how cold is it on a 2,000 m peak? (20 − 13 = 7 °C.)

Key formulas and definitions

Worked examples

1. A peak is 2,544 m high and the plain at its foot is 100 m. What is the height difference?

2,544 − 100 = 2,444 m.

2. A town on the plain has 22 °C. How cold is it at a village at 1,000 m?

Fall = 0.65 × (1,000 ÷ 100) = 6.5 °C. So 22 − 6.5 = 15.5 °C (the plain is at about sea level).

3. A river drops 600 m over a 120 km stretch. Find the gradient.

600 m ÷ 120 km = 5 m per km.

4. Why is the Danube Delta so flat and low?

The river slows down at the sea and drops the mud it carried. The mud piles up as low islands, so the land only reaches a few metres above sea level.

Common mistakes

Practice quiz

1. Which belt is usually the highest in a country's relief?
2. A flat-topped high land cut by valleys is a:
3. A delta forms where:
4. The Transylvanian Depression is:
5. Temperature falls about ___ for every 100 m of height:

Practice: answer these yourself

Type or choose your answer, then press Check. Use a hint if you are stuck; the full solution appears after you answer.

Frequently asked questions

What is relief in geography?

Relief is the difference in height of the land: mountains, hills, plateaus, plains and valleys.

What are the main relief units of Romania?

The Carpathian Mountains with the Transylvanian Depression, the Subcarpathians, the Getic, Mehedinţi, Moldavian and Dobruja plateaus, the Western Hills and Plain, the Romanian Plain, and the Danube Delta with the Black Sea shelf.

Why do countries have belts of relief?

Slow movements of the Earth's crust lift mountains. Rivers and rain wear them down and carry the material to lower land, so hills, plateaus and plains appear in steps.

Where this is taught

RomaniaClasa a VIII-aLandforms of Romania
China八年级（初二）Ch.2 Natural environment

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