Vertical spacing refers to the vertical distance between two adjacent horizontal sections, which is also a basic geological concept and one of the important parameters. It is widely used in practical geological exploration, deposit investigation and hydrogeology. This paper will explain the vertical spacing in detail from the concept, calculation method and application of vertical spacing.

1, the concept of vertical interval

Vertical spacing refers to the height difference between two adjacent contour lines. It refers to the vertical height difference between every two adjacent contour lines, which can be called vertical spacing.

Isograms are sometimes called contours or equipotential lines. An isoline is a line formed by any two points with equal elevation. Vertical spacing describes the spacing between contour lines. The greater the vertical spacing, the greater the height difference and the faster the terrain changes, and vice versa.

2. Vertical interval calculation method

The vertical interval represents the height difference between two adjacent isolines (contours) in the height field. There are usually three methods to calculate the vertical spacing:

(1) The actual vertical height difference between different contours is obtained through field measurement.

(2) The topographic map method calculates the vertical spacing by measuring the distance between different contour lines on the map and the elevation information of elevation points. That is, the area of each contour line (generally square or rectangle) is framed by parallel lines, and the number of contour lines per unit area is calculated, and then divided by the area to get the actual vertical interval.

(3) The mathematical model method uses the existing information to calculate the elevation data of contour lines and then calculate the vertical distance by calling the mathematical model. This method is usually obtained by vertical interval interpolation algorithms such as kriging interpolation or inverse distance weighted interpolation.

3. Vertical spacing application

Vertical spacing is widely used in topographic survey, geological exploration, petrochemical industry, hydrogeology and other fields. In map drawing, contour lines can reflect the characteristics of terrain. According to the different terrain, drawing contour lines can obtain rich terrain information.

Combined with vertical interval, terrain fluctuation can be quickly judged, and contour line can also be used as an index to distinguish terrain categories. In the actual exploration of mineral deposits, isoline and vertical interval are also one of the very important exploration methods. The difference of topography on the ground has a great influence on the occurrence mode of underground rocks and mineral deposits and the spatial position of collections.

Through the difference of vertical spacing, the regional distribution of the deposit can be determined in the exploration, which provides the basis for the actual exploration of the deposit. In the field of hydrogeology, the change of water level can be reflected by contour lines.

In the practical application of hydrogeology, considering the potential harm of groundwater level, isoline equivalence can be used to reflect the scope and degree of underground settlement or uplift, which provides convenience for the planning and design of water conservancy projects.