中文摘要：

以龙口市2004年1∶10000土地利用现状更新调查结果和等高线等地形资料为基础数据,借助于Arc-view软件,首先利用矢量化的等高线生成DEM数据并自动提取坡度信息,然后计算坡度的正割值,再与龙口市的林地栅格数据结合,完成研究区内几种林地在不同坡度级上表面积的统计。最后将该方法获得的林地面积与利用土地类型栅格数据求算的林地投影面积作比较分析。

英文摘要：

Using Longkou city as a case study, this paper mainly introduces the use of DEM obtained from contours by digitizing the relief map, and the use of grid, which has the same resolution as DEM, for the forestland of Longkou to calculate surface area of different forest at different slope based on GIS. In order to calculate the surface area, the slope and secant should be obtained at first. Slope can be extracted from DEM automatically. Secant can be obtained from slope information. Combined with the slope,the forestland and the secant information together, the study was finished to calculate the surface area of different forestland at different slope. At last, we compared the surface area with the vertical projection area.