Bhabar, bhangar, khadar and terai are the geological divisions of alluvial soils.
- Bhabar: It is found in the foothills of Shivaliks. It is 8 to 16 kms wide. It comprises of pebble studded rocks and hence no rivers. It is not suitable for agriculture.
- Bhangar: It covers large parts of northern plains. It is composed of old alluvial soil. It contains calcareous deposits locally known as 'Kankar'. Soil is not very fertile.
- Khadar: Ii is also present in northern plains like that of Bhangar. It contains new alluvium. Used extensively for agriculture.
- Terai: It is composed of comparatively finer alluvium and is covered by forests. It has underground streams and makes the area marshy. Suitable for agriculture.