What are the 3 factors that should be considered upon planning and designing of a contour interval to be used for a topographic map?
The Contour Spacing Depends On The Following Factors:
- The Scale of The Map. The contour interval is inversely proportional to the scale of the map.
- Nature of The Ground.
- Purpose and Expansion of the survey work.
- Time available and Eligible Expenses for field and office work.
How far apart are contour lines on a map?
Contour lines are generally illustrated as a brown line. Individual contour lines on a topographical map are a fixed interval of elevation apart known as a contour interval. Common contour intervals are 5, 10, 20, 40, 80, or 100 feet.
What is a topographic contour line?
Topographic Contours. Topography, or the shape of the Earth’s surface, is mapped and displayed on topographical maps. Contour lines, or lines which connect points of equal elevation, are drawn on a topographical map in order to quantify the elevation at any point on the map.
How do you plot a strike and dip on a map?
The dip direction is always perpendicular to the strike direction, but it is important to note the right hand rule, which states that the dip-direction must be located clockwise with respect to the azimuth chosen for strike.
How do you write a strike and dip?
Some geologists prefer to use whichever strike direction is less than 180°. Others prefer to use the “dip-direction, dip” (DDD) convention instead of using the strike direction. Strike and dip are generally written as ‘strike/dip’ or ‘dip direction,dip’, with the degree symbol typically omitted.
What are the methods of contouring?
There are basically 2 methods of contouring – Direct Method and Indirect Method.
- Direct Method of Contouring : High degree of precision is required for large-scale maps with small contour interval.
- Indirect Method of Contouring : It is suitable for undulated ground and hilly areas.
How do you calculate dip on a map?
You can usually determine the dip direction of inclined beds by looking at the direction of the V that forms when the bed crosses a valley on a map. This resulting V may or may not point in the direction the bed dips, depending on the slope of the valley.