Question

To visually distinguish between a river channel and a canal on an image, having similar widths and located in the same area, the most important parameter used is _______________

• A. size
• B. shape
• C. tone
• D. texture

Hint:

When interpreting man-made vs natural linear water features: use {shape/pattern}. Man-made features tend to be straight/regular; natural ones are meandering/irregular.

Answer 1

The Correct Option is B

Visual interpretation keys include tone/color, texture, shape, size, pattern, shadow, site, and association. For river vs canal with similar widths and in the same area:
- Rivers are typically sinuous/meandering, branching, with irregular planform.
- Canals are straight or regularly aligned and engineered, often with right-angle turns or uniform alignment.
When tone and size are comparable, the shape (planform geometry) is the most discriminative cue.
\[ \boxed{\text{shape}} \]