等高距

对于采用本方法计算淹没区，准确性受地形图等高距大小、数字化采集精度、数字地面模型（DEM）高程精度以及格网间隔大小、像素探测分辨率等因素的影响。

The accuracy of flood area is mostly dependent on the contour interval of map , accuracy of digitizing map , accuracy of DEM , and interval of GRID , detecting resolution of pixels .

为了满足等高线三维显示的需求，需要等高距不同但彼此相容的等高线。

In order to cater the 3-D showing of contour line , we should generate different contour interval lines and compatible with each others .

基于GIS地貌形态特征分形信息维数与等高距关系研究

Study on Relationship Between Topography Characteristics Fractal Information Dimension and Contours Line Interval Base on GIS

然后在生成的栅格DEM上随机选取检测点，计算中误差进行精度评定，并用栅格DEM提取同一等高距的等高线图与原等高线图作比较。

Then randomly selected detection point on the created grid DEM and calculated RMSE to assessing the accuracy . And then compared the contours map extractied from grid DEM to the original contour map .

用变距等高距选取了少量对划分草地类型界线、重要牧草分布界线、季节草地界线有重要指示意义的等高线。

A few contour lines which have significance to delineate the grassland types , the distribution of herbages and the seasonal grassland are chosen by using different contour intervals .

等高圈天顶距的稳定，对等高星表的△αδ系统差的影响不明显。

Systematic error influenced by stability of zenith of altitude circle is not distinct .