Contour | Contour Gradient
What is Contour?
A contour is an imaginary line on the bottom joining the purpose having equal elevation or a line joining the points of an equivalent elevation is understood as a contour .
A map or plan representing a three-dimensional picture of the bottom with the assistance of the contour is named a relief map or plan.
What is Contour Gradient?
A line contact the bottom which maintains a continuing inclination to the horizontal is understood as contour gradient. it's acknowledged by instrument clinometer.
Characteristics of the contour
1. All the points on a contour have an identical elevation.
2. Two contour never intersect one another because each contour represents own elevation. But just in case of the overhanging cliff, the contour lines cross one another .
3. Spacing between contour lines indicates the character of the bottom
- Closely Spaced - Steep slope
- Wide apart - gentle or flat slope
- Equally spaced - uniform slope
4. For undulating ground or broken surface, the contours are irregular, whereas for a plane surface they're straight, parallel and uniformly spaced.
5. Contour lines, cross ridgelines (watershed lines) and valley lines at right angles. For ridgeline, the upper elevation contours are inside the loop or bend. Valley line indicated by higher elevation contours outside the loop. Valley lines indicate streams or rivers.
6. A series of closed contour lines with higher elevations inside the loop indicates a hill. if in such a closed-loop system , lower value of contour is inside, it indicates depression or pond.
7. A contour always closes on either inside the boundary maps or outside it.