利用C++语言，进行DEM中汇水的计算。在程序中初始设定的DEM中每个格的值，进行坡度坡向的计算。是学习GIS初学者很好的代码！-Use C++ language, the calculation of the DEM catchment. DEM initial set in the program each cell' s value, the calculation of slope and aspect. Learning GIS beginners a good code!

主要应用于GIS领域，根据DEM数据，计算填挖方面积。(According to the DEM data, the excavated area is calculated.)