Ans.

Three differences between Seef Balukastupa and Barkhan:

Seif dune

1 Sword-shaped mound is called Seif in the Sahara desert.

2 They are formed parallel to the direction of airflow. Hence it is called longitudinal or longitudinal sand stupa.

3. They are not transferred, they are several kilometers long and 40 to 70 meters high.

Barkhan

1. A crescent-shaped or arc-shaped dune is called Barkhan in the Sahara desert.
2. They are formed perpendicular to the direction of airflow, hence they are called transverse sand stupas.
3. They keep on shifting, these mounds are up to 120 meters high and up to 3 kilometers long.