中文摘要：

将从遥感影像中提取的面积直接在分析中使用容易引起垂直投影面积和地表真实面积的概念混用，针对此问题设计了理想状态下的虚拟实验进行研究。使用1：1万的DEM模拟出不同的地表类型，计算每一种地表类型下的两种面积大小，分析两种面积之间的差值随地表类型变化的规律。实验结果表明，两者差异随地表起伏加剧而不断增加，当地形坡度均值为44．34°时，两者之间的差异达到38．08％。因此，遥感影像的垂直投影面积并不能完全作为地表真实面积在所有地袁类型下使用，尤其是对地形起伏较剧烈的地区而言，为了更准确的精度应尽可能地使用地袁真实面积。

英文摘要：

Using planimetric area instead of true surface area is one common problem in applications based on remote sensing data. To put a premium on this problem, it was much better to analyze the difference between these two area concepts in a quantitative way. This article designed a virtual experiment to do the research. Different kinds of land surface were simulated based on one 1 ： 10 000 DEM, after that, two kinds of area were computed and then the difference according to land types was analyzed. The result shows that the difference gets more when lands＇ fluctuation get more, with a difference of 38.08% when the average slope gets 44.34°. The result shows that the planimetric area can not always take for true surface area, and the latter should be employed to make the result more precise.