Controls of Dune Morphology in the Namib Sand Sea

Abstract

This chapter examines the controls of dune morphology in the Namib sand sea. With the advent of satellites and other remote sensing imagery devices, mapping of desert areas have been facilitated and they have shown a great variety of dune morphology in sand seas. The data obtained from remote sensing imagery is combined with field observations and measurements of dune morphometry and sediments at 26 sites throughout the sand sea. Three major dune types occur in the Namib sand sea. The northern group of transverse dunes begins on the coast southeast of Meob Bay and continues to the northern boundary of the sand sea at the Kuiseb River. Most dunes in this area are large compound forms consisting of a main transverse ridge with small barchanoid ridges on their crests and upper southwest slopes. Between Meob and Conception Bays there are areas of barchans and small transverse and barchanoid ridges. Some of these join the main area of compound transverse dunes from the west. It is found that rolling dunes without slip faces in the area south of the Uri Hauchab Mountains have a similar morphometry to that of compound transverse dunes.