墨卡托投影，与地轴方向一致的圆柱切于或割于地球，按等角条件将经纬网投影到圆柱面上，将圆柱面展为平面后，得平面经纬线网。投影后经线是一组竖直的等距离平行直线，纬线是垂直于经线的一组平行直线。各相邻纬线间隔由赤道向两极增大。一点上任何方向的长度比均相等，即没有角度变形，而面积变形显著，随远离标准纬线而增大。-Mercator projection is consistent with the direction of the Earth s axis cylinder cut in or cut i

水动力软件利用SMS划分网格,然后转成mike的mesh,不过SMS网格质量检查没有修改单元面积变化过大的问题,其他都修改过,转成的mesh也能在m2(The hydrodynamic software is divided into grids by SMS, and then converted to Mike mesh. However, the SMS grid quality check does not modify the problem of large unit area ch