18.a Introduction

Deserts are stretches of dry, arid land with little rainfall and sparse vegetation. There are many different benchmarks used to numerically define deserts, but a common one is that deserts are regions with less than 250 mm of rainfall in a year. (​​https://pubs.usgs.gov/gip/deserts/what/).

Deserts are home to fascinating ecosystems and striking landforms. Here we will understand where and why deserts occur and explain some of the unique land features that develop in desert regions.