How many methods of contouring are present? Explanation: There are 2 methods of contouring: direct and indirect. In direct method, the points of elevation are located physically and then plotted on the map. Indirect method uses contouring with the help of grids.
What is one significance of the direct method of contouring?
In the direct method, the contour to be plotted is actually traced on the ground. … This method is slow and tedious and thus used for large scale maps, small contour interval and at a high degree of precision and hence more accurate than the other methods of contouring.
How many indirect methods of contouring are there?
There are two different ways usually employed for indirect method of contouring: Grid method and. Radial line method.
Which method is the most accurate method of contouring?
Direct method of contouring is the most accurate but very slow and tedious as a lot of time is wasted in searching points of the same elevation for a contour. Direct Method of Contouring is suitable for small areas and where great accuracy is required.
Which method is suitable for contouring of hilly areas?
Cross Section method
This method is generally used for hilly terrain to produce contour lines.
What is block contouring?
By squares (block contouring)- In this method the area to be surveyed is dividing into no of the square of size 5 to 20m. depending upon the nature of ground and contour interval required. The elevation of the corner of the square is determined by the mean of the process of levelling.
What are the two 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.
What is Tacheometric method of contouring?
Tacheometric Method: Tacheometric method of indirect contouring involves the setting out of the radial lines by making different angles with respect to a reference line. On each of the radial lines, the tacheometric readings are then taken on the levelling staff kept at different points.
What method of contouring is used for small areas work with high precision?
Direct Method:
This method is the most accurate but very slow and tedious as a lot of time is wasted in searching points of the same elevation for a contour. This is suitable for small areas and where great accuracy is required.
What is contouring and its characteristics?
Contours show distinct characteristic features of the terrain as follows: i) All points on a contour line are of the same elevation. ii) No two contour lines can meet or cross each other except in the rare case of an overhanging vertical cliff or wall. iii) Closely spaced contour lines indicate steep slope.
What is radial contouring?
Methods of Contouring Radial Line Method or Tachometric Method • In this method, a number of radial lines are set out at known angular interval (i.e. 15 0 or 30 0) at each station. The point are selected on a line depend on the nature of the ground surface. Instead of the level, a tachometer may be used.
What are the characteristics of contour lines?
Characteristics of Contours
- Must close on themselves, on or off the map.
- Perpendicular to the direction of max. …
- Slope between them is assumed uniform.
- The distance between them indicates the steepness of the slope, gentle or steep.
- Irregular signify rough, smooth signify gradual slopes.
What is grade contouring?
Contour grading means grading that creates or results in land surfaces that reflect the pre- graded natural terrain, or that simulates natural terrain (i.e. rounded, non-planer surfaces and rounded, non-angular intersections between surfaces).
What are the types of contour lines?
Contour lines are of three different kinds. They are the Index lines, Intermediate lines and the Supplementary lines.
Why can’t contour lines cross?
Contour lines never cross on a topographic map because each line represents the same elevation level of the land.
What is purpose of contouring?
Contouring is a technique for sculpting and adding dimension to your face by using makeup that is slightly darker or lighter than your actual skin color. Unlike everyday foundation and concealer, which we typically want to match our skin exactly, contouring is all about creating the effect of shadow and light.
Which is Tacheometric method?
Tacheometry (/ˌtækiˈɒmɪtri/; from Greek for “quick measure”) is a system of rapid surveying, by which the horizontal and vertical positions of points on the earth’s surface relative to one another are determined without using a chain or tape, or a separate levelling instrument.
What is contour interpolation and its method?
Interpolation of the contours is the process of spacing the contours proportionately between the plotted ground points established by indirect methods. The methods of interpolation are based on the assumption that the slope of ground between the two points is uniform.
What are the types of Levelling?
The different types of leveling
- The different types of leveling.
- I ) Direct Leveling : Direct measurement, precise, most commonly used;
- Types:
- (1) Simple leveling : One set up of level. …
- Differential leveling :
- Fly leveling :
- Precise leveling : Precise form of differential leveling.
How do you find contour lines?
You can find the contour interval in the map key, usually located underneath the scale of the map at the bottom center. To understand all map symbols, see the US Gov document. Example: The contour interval is 50 feet according to the map key.
What is the vertical distance between two consecutive contour?
The vertical distance between any two contours is called a contour interval. Explanation: The vertical distance between any two consecutive contours is called a contour interval. The contour interval is kept constant for a contour plan.
What is contouring in agriculture?
Contour farming, the practice of tilling sloped land along lines of consistent elevation in order to conserve rainwater and to reduce soil losses from surface erosion.
What is the contour interval?
A contour interval is the vertical distance or difference in elevation between contour lines. Index contours are bold or thicker lines that appear at every fifth contour line. If the numbers associated with specific contour lines are increasing, the elevation of the terrain is also increasing.
Which is the arithmetic check for the height of instrument method?
Which is the arithmetic check for the height of instrument method? Explanation: To check if the readings are written properly, an arithmetic check is done. The sum of back sight (BS) and Fore sight (FS) are subtracted. It should be equal to the difference of the last and first reduced level (RL).