The contour interval depends upon the general topography of the terrain. In flat ground, contours at small intervals are surveyed to depict the general slope of the ground whereas high hills can only be depicted with contours at larger contour interval.
Simply so, What does the spacing of contours indicate? Spacing tells us about the slope. Given that the two images are from a map of the same scale, we can state that where the contours are closer together, the slope is steeper. Closer spacing of contours tells us that elevation is changing faster over distance, in other words, a steeper gradient.
How are contour lines drawn on maps? Contour lines are lines drawn on a map with equal elevation points, so elevation would be constant if you followed the contour line physically. The elevation and terrain shape of the contour lines shows. It is useful because they show the form of the land surface on the map–its topography.
Subsequently, What is the difference between contour interval and horizontal equivalent?
Contour Interval: The constant vertical distance between two consecutive contours is called the contour interval. Horizontal Equivalent: The horizontal distance between any two adjacent contours is called as horizontal equivalent. while the horizontal equivalent is variable and depends upon the slope of the ground.
What are the 3 factors that should be considered upon planning and designing of a contour interval to be used for a topographic map?
What are the 3 factors that should be considered upon planning and designing of a contour interval to be used for a topographic map?
- 1) Scale of the map. The contour interval is kept inversely proportional to the scale of the map. …
- 2) Purpose of the map. …
- 3) Nature of the ground. …
- 4) Availability of time and funds.
What are the 5 Rules of contour lines? Rule 1 – every point of a contour line has the same elevation. Rule 2 – contour lines separate uphill from downhill. Rule 3 – contour lines do not touch or cross each other except at a cliff. Rule 4 – every 5th contour line is darker in color.
What are 3 types of contour lines?
There are 3 kinds of contour lines you’ll see on a map: intermediate, index, and supplementary.
- Index lines are the thickest contour lines and are usually labeled with a number at one point along the line. …
- Intermediate lines are the thinner, more common, lines between the index lines.
What are the geographical features formed by contours? A single contour line joins the places of the same elevation. It can help to distinguish between mountains, ridges, plateaus, valleys, hills, gullies, etc. It can also differentiate between a steep and gentle slope of a hill or mountain.
What do contour lines on a topographic map represent?
Elevation contours are imaginary lines connecting points having the same elevation on the surface of the land above or below a reference surface, which is usually mean sea level. Contours make it possible to show the height and shape of mountains, the depths of the ocean bottom, and the steepness of slopes.
How contours are drawn during topographical survey? In this method, the contours to be located are directly traced out in the ground by locating and making a number of points on each contour. These points are then surveyed and plotted on plan and the contours drawn through them.
How do you draw topographic contour lines?
Is the contour interval constant? Contour: Line joining points of the same elevation is called contour line. … The elevation difference between two consecutive contours is called contour interval. It is always kept the same or constant for a map.
What are various uses of contour map?
Uses of Contour Mapping
The Contours provide important information which can help us to study the nature of the terrain. This proves to be useful for the selection of sites, to determine the catchment area of a drainage basin, or to find intervisibility between two or more stations, etc.
What is contour map surveying?
In land surveying a contour map is a map illustrated with contour lines, for example a topographic map, which thus shows valleys and hills, and the steepness or gentleness of slopes.
What is the vertical distance between two consecutive contour? Contour elevation:
This vertical distance between any two contour lines on a map is called the contour interval.
How do you read a contour plan?
What are the characteristics of contour?
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 the contour interval in Figure 2? Contour interval is the difference in elevation between two adjacent contour lines. In Figure 2-5, the contour interval is 40 feet.
How do contour lines indicate streamflow on a topographic map?
All rivers flow downhill from higher to the lower elevations, perpendicular to the contour line above it. As a rule of thumb, the V-shaped contour is pointing upstream (the opposite direction from the flow of a stream or river). The “V” shape contours indicate streams and drainage.
What is the elevation between contour lines? The elevation difference between two adjacent contour lines is called the contour interval (CI). Usually the contour interval is noted on the map legend. In most topographic maps every 5th contour line is drawn in bold print or wider than other contours. Such lines are called index contour lines.
What are 4 types of contour lines?
Types of Contour Lines in Surveying and their Importance
- Isopleth.
- Isohyet.
- Isobar.
- Isobath.
- Isohaline.
- Isotherm.
- Isohel.
- Isohume.
What are the factors affecting the contour interval? 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.
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