【摘要】 为考察地形离散影响和平滑效应对地形特征计算的影响与地形类型和DEM分辨率间的关系,选取洞庭湖水系湖南地区SRTM3数据,通过对比原始1001、000 m和新100 m分辨率的三种DEM数据计算的地形特征均值发现:DEM分辨率对坡度和地形指数计算的影响主要来源于平滑效应,而对单宽集水面积计算的影响主要由离散化造成;地形离散化和平滑效应程度与地形类型相关,主要体现在与地形起伏程度和尺度特征的相关性上;随着DEM分辨率的增大,离散化对坡度的影响、平滑效应对集水面积和地形指数的影响逐渐趋于稳定,其他呈继续增大的趋势。更多还原

【Abstract】 In order to examine the relationship between the terrain-discretization and terrain-smothing effects on topographic characteristics computation and the terrain type and DEM resolution,DEM for 57 locations containing 500 rows × 500 columns and DEM for 1 location composing of 1500 rows × 1500 columns derived from SRTM3 data are used.By comparing the topographic characteristics computed from the original 100m,1000m and new 100m DEM,it can be concluded that the effects of DEM resolution on slope and topographic index mainly result from terrain smoothing,and the terrain discretization accounts for most of the difference between upslope contributing area per unit contour values calculated from 100m and 1000m DEM.The terrain discretization and smoothing are influenced by terrain type.Both of them are related to the terrain variation and scale feature.As the DEM resolution increases,the discretization effect on slope and the smoothing effects on upslope contributing area and topographic index will become gentle,and other will keep on augmenting.These three conclusions can be regarded as the theoretic basis for solving the hydrologic scale issue.更多还原