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一、坡度大小的判断原理如图1,AC为一坡面,a为坡度,HG、FD、BC为等高线,则DE为等高距,在直角三角形中,a的正切值=DE/CE。若正切值在0°-90°的范围内为增函数,则DE/CE比值越大,坡度就越大。二、不同等高线图上判断坡度大小的方法1.根据等高线疏密判断在比例尺和等高距相同的等高线地形图上,相同水平距离上的等高线越密集,坡度就越大;等高线越稀疏,坡度就越小。如图2中四幅图的坡度为C>A>D>B。
First, the judgment principle of slope size is shown in Figure 1. AC is a slope, a is a slope, HG, FD and BC are contour lines, and DE is a contour height. In a right triangle, the tangent of a is DE/ CE. If the tangent value is an increasing function in the range of 0°-90°, the greater the DE/CE ratio, the greater the slope. Second, different slope maps to determine the size of the slope method 1. According to the density contour density judgments in the same scale and the same height contour contour map, the more horizontal contour lines on the same density, the slope Larger; the more sparse the contours, the smaller the slope. The slopes of the four graphs in Figure 2 are C>A>D>B.