(a) Name three processes of wind transportation in an arid region. (b) With the aid of a diagram, describe the characteristics and mode of formation of a de...

Answer Details

(a) The three processes of wind transportation in an arid region are:

1. Suspension: In this process, fine particles such as dust and sand are lifted by the wind and carried in the air. These particles remain suspended for a significant period, sometimes traveling long distances before settling back to the ground.
2. Saltation: It is the transportation of relatively larger particles like sand grains by a series of short jumps or bounces along the ground. As the wind blows, it lifts the sand grains a short distance above the surface and then gravity pulls them back down. This bouncing motion causes the sand grains to collide with other particles, dislodging and moving them in the process.
3. Surface creep: This process involves the movement of larger particles or pebbles by rolling or sliding along the ground surface. As the wind blows, it pushes the particles in contact with the ground, causing them to move slowly across the surface. This process is generally limited to larger and heavier particles that are less prone to being lifted by the wind.

(b) A deflation hollow is a shallow depression or basin formed by the removal of loose sediment by wind erosion. Here is a simple explanation of its characteristics and mode of formation:

A deflation hollow begins with loose sediments, such as sand or silt, deposited on the ground. Wind, being a powerful agent of erosion, picks up these loose sediments and transports them away. However, in certain areas where the sediments are less cohesive or protected, wind erosion can be more intense, leading to the formation of a deflation hollow.

The process starts with the wind removing the finer and lighter particles from the surface, leaving behind the larger and heavier particles. Over time, the wind continuously erodes the exposed surface, deepening the depression. The deflation hollow usually has a concave shape, with its center being the lowest point. The steep slopes surrounding the hollow are often formed by wind erosion undercutting the edges of the depression.

Here is a simple diagram to help visualize the characteristics of a deflation hollow:

                ____
              /        \
             /   Deflation   \
            /      Hollow       \
           /_________________\

In summary, a deflation hollow is a shallow basin formed by the removal of loose sediments through wind erosion. It has a concave shape with steep slopes and is formed when wind selectively removes finer particles, leaving behind a depression in the landscape.