The Availability Of Sediment On Drylands

Question 1

What are the 3 types of sediment available deserts?

Answer 1

Reg (Stony), Hamada (Rocky) and Erg (Sandy)

Question 2

What is a Reg desert?

Answer 2

In most drylands sediment is scarce, and the ground may be covered with densely-packed stones forming a desert pavement after deflation has occurred (removing finer sediments through wind action).

Question 3

What is a Hamada?

Answer 3

Hamadas are hard, rocky plateaus which are at high altitudes and are largely barren, with little sediment availability as wind action has carried away most of the sand.

Question 4

What is an Erg dryland environment?

Answer 4

This generic term describes large expanses of sandy desert. Large sediment supplies are derived from pluvial conditions, which create sand seas as seen across the Sahara. Variable relief allows mountains to be eroded, granting more sediment to an erg dryland. Sediment carried in rivers from the mountains where it is more likely to rain are deposited onto adjacent plains, creating alluvial fans and bajadas.