Answer:
A Gulch is a deep V-shaped valley formed by erosion. It may contain a small stream or dry creek bed and is usually larger in size than a gully (a landform created by running water, eroding sharply into soil, typically on a hillside).
In parts of the northeast U.S. the word "gulf" is used for gulch.
A Dry Gulch is a gulch void of surface water flow and typically located in a dry climatic area suchas a desert. The creek that may have run along the bottom of such a gulch in the past has been diverted to a parallel aryk (a Central Asian term widely used to describe a small irrigation canal, where in most areas agriculture is impossible without some measure of artificial irrigation).