A method for drawing slope maps from contour maps by automatic data acquisition and processing

A method for drawing slope (angle) maps is described. After the contour lines of a topographic map have been expressed in digital form by a digitizer, the ground surface is considered as a set of partly overlapping trend surfaces. Slope values then are calculated at the mesh points of a grid superimposed on each of these mathematically expressed surfaces. The final map consists of a set of isolines (isoclines) obtained by slope values interpolation. The computer is used to determine the slope values, whereas the final map is obtained by a plotter.