What are the methods of topographic mapping?

What are the methods of topographic mapping? Topographic map is an indispensable tool for us to understand the terrain at ordinary times. Although the topographic map looks simple, there are many methods and skills in the actual surveying and mapping process. In the past, when the technology was underdeveloped, topographic maps needed pure manual mapping, which was very troublesome, but now there are many methods. What are the methods of topographic mapping? Come and have a look with us!

What are the methods of topographic mapping?

It can be divided into theodolite mapping method, large flat plate mapping method, small flat plate mapping method combined with theodolite, photogrammetry method and so on. Among them, photogrammetry is generally used to map small and medium-scale topographic maps, while other methods are mainly used to map large-scale topographic maps. This topic mainly introduces this method. Water system should draw bridges and sluices first, then double-line rivers, lakes, canals, coastlines and single-line rivers, and then banks, steep slopes, beaches and ferries. When the river meets the bridge, it will be interrupted; When the single-line ditch intersects with the double-line river, the waterline should be disconnected and bent at one point; When two two-lane rivers intersect, they should be connected to each other.

Basic methods of topographic mapping

It is necessary to carry out complex topographic survey before drawing topographic map, and then draw the map by scientific method according to the data obtained from topographic survey. Generally speaking, a topographic map has three elements, including orientation, distance and elevation. Before drawing a topographic map, you should set the direction on the topographic map. Generally, topographic maps are drawn in the traditional direction of upper north and lower south.

After determining the direction, determine the coordinate origin and elevation zero on the topographic map as reference points. After doing this, mark the features obtained by topographic survey on the topographic map, express them with various symbols, and draw them with contour lines according to the shape and height of each feature. How to use surveying and mapping topographic map

1. Without topographic map, no project can be built.

Therefore, we must be familiar with the following issues: (1) the framing, numbering and outline of topographic maps; Topographic map coordinate system; Height system; Scale and orientation of topographic map; Topographic map schema; Outline, etc. 2. For map users, only by mastering the method of evaluating the accuracy of topographic maps can they correctly choose the topographic maps that meet the requirements. When selecting topographic map, we should not only consider the accuracy of point and elevation, but also consider the design object and other factors.

3. The basic contents of topographic map application are: determining the coordinates, side lengths and azimuth angles of design points on the map; Find the height of any point on the map; Find the slope of vegetable straight line on the map; Select the shortest route on the map according to the restricted slope; Draw a paragraph in the known direction on the topographic map.

4. The application of topographic map in engineering planning and design is: irrigation and drainage engineering planning; Calculate the catchment area and reservoir capacity on the topographic map; Determine the toe line of the dam slope on the map; Level the field, etc.

The above is the introduction of topographic mapping methods, hoping to help everyone.