岩组图、节理等密图的作法很多。常用的作图法有方格法、圆圈法、波娄尼法、自由计量法、等密最大范围法等,其中波娄尼法较易掌握,作图快速方便。但该法所对圈定的面积歪曲较大,不宜用来统计对比单位面积内点的数量。波娄尼网不是等积投影网,它是按照吴氏网设计的(图1),与施密特网并不配套,在构造地质作图方面用途较少。为了克服波娄尼 Rock group map, joint dense map practice many. Commonly used method of drawing a square method, the circle method, Boluni method, free measurement method, the maximum density range method, etc., which Bolanni method easier to grasp, drawing fast and convenient. However, the law of the delineation of the larger distortion of the area should not be used for statistical comparison of the number of units within the area. Bollo Nirvana is not an isosceles projection network, which is designed according to Wu’s network (Fig. 1), which is not compatible with the Schmidt network and uses less in the construction of geological mapping. To overcome Boltoni