中文摘要：

以陕西省671幅1：50000比例尺，25m分辨率的DEM数据为信息源，分析DEM分辨率对提取坡度信息的不确定性影响。研究表明：平均坡度随DEM分辨率的减小呈显著递减型二次曲线变化，但当DEM分辨率减小到一定程度时。平均坡度将趋于稳定：并且，随DEM分辨率变化，坡度的不确定性呈现明显的空间结构性分布，DEM栅格单元内部地形的复杂性和变异性越大．坡度提取不确定性越大．如沟坡地坡度提取误差明显大于沟间地。因此，实际应用中要充分考虑研究区域DEM地形描述的尺度效应和不确定性问题，选择合适尺度的DEM提取坡度信息，保证提取结果的科学有效。

英文摘要：

Slope is one of the crucial terrain variables in spatial analysis and land use planning. DEM based slope extracting method has been widely used in practice. However, the slope data uncertainty which is very important to the applications has always been neglected. This paper focuses on how resolution affects the uncertainty of the slope extracted from DEMs in Shaanxi Province. Taking 1：50 000 DEM with a resolution of 25m with a total of 671 sheets of Shaanxi as source data. The research shows that the average slope reduction along with the DEM resolution assumes a conic trend, but when the DEM resolution reduces to a certain degree, the average slope would tend to be stable; and from the result of the comparison of the slopes derived from different resolutions, we can see that the slope uncertainty presents an obvious spatial constitutive distribution.