The correct determination of the slope slope in the field is very important for assessing the terrain. In order to assess the steepness of slopes by eye, it is necessary to study the terrain and fix in the visual memory the steepness of several typical slopes of 15, 30, 45, 60 degrees, and then, by mental comparison with them, determine the steepness of other slopes.
Determination of the slope slope using an eye, fingers, according to the formula and using an eclimeter.
It should always be remembered that from below, from the bottom of the hill, the ramp always seems steeper than in reality. More accurate results of determining the slope slope are obtained by going to the side of the slope and comparing it by eye with the size of any existing celluloid triangle. The values of its angles must be known in advance.
Having previously measured the angles between the fingers, index and middle fingers, arranged as wide as possible, you can also use these angles to evaluate the slope of the slopes on the eye.
Determination of the slope slope using the approximate formula.
The slope of the slope can also be determined by measuring the steps using the approximate formula.
Slope slope = 60 / PS
Where PSh – the length of the slope measured in pairs of steps.
To determine the slope slope using this formula, the observer becomes at point A. Holding a horizontal folder or book at eye level, looks along it and notices point C on the slope, equal in height to the eye level. Then, moving towards this point, the number of pairs of steps is measured and the slope of the slope is determined by the formula. For example, from point A to point C, 4 pairs of steps are counted slope slope = 60/4 = 15 degrees.
Determination of the slope slope using an eclimeter.
The steepness of the slopes can be measured using an eclimeter, a goniometer for measuring the slope of terrain lines to the horizon. To determine the slope of the ramp using an eclimeter, it is held at eye level so that the base line AB is parallel to the direction of the ramp.
Usually a milestone is placed at a certain distance with a mark on the height of the observer’s eyes. Then the plumb line of the eclimeter will show an angle equal to the slope of the slope.
A homemade eclimeter can be done with a simple protractor. A thread is fastened to the protractor shelf in the center (in the middle) and the protractor is turned upside down by the shelf, and its edge is directed parallel to the side surface of the ramp. The cargo line deviates from dividing 90 degrees on the protractor scale by an angle equal to the slope of the ramp.
Based on the book “Map and Compass My Friends”.