History I / Remote Sensing and Geophysics
Practice question · Multiple choice

A parched cropmark and a lush green one appear side by side in one field. Why do buried features produce opposite signals in the same drought?

Hints
  1. Ask what lies under each kind of mark.
  2. What does a crop do when it has more water than its neighbours?
Show the answer

C. Because a buried ditch holds damp fill and stone leaves it dry

Why

The crop is a moisture gauge. A ditch stores water and a wall steals it, so one feature makes the crop thrive and the other makes it fail, in the same field on the same day.

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