坡度分级方法对坡度制图的影响

目的]利用多种分级方法进行坡度制图,探究不同分级方法对坡度制图带来的影响。方法]选取陕西省绥德县,陕西省眉县境内的秦岭山区,黑龙江拜泉县的3个样区,用多种分级法对坡度进行分级,利用量化指标分析坡度分级对坡度格局和统计分布的影响。结果](1)就一个样区而言,分位数或Evans分级法比较好;不同地区比较,选用统一分级方案较好;(2)分级后的坡度空间变异急剧减少;(3)所有分级都使坡度信息有所损失;(4)所有分级均难以准确表现坡度的统计分布规律。结论](1)坡度表面和自然断点分级方法效果较好。(2)随着分级间距的增加,坡度信息量快速减少。(3)坡度统计分布的分析须用坡度表面和自然断点分级进行制图。

Influence of Slope Classification Method on Slope Mapping

Objective] A variety of slope classification methods was applied for slope mapping to explore the influence of different methods on them.Methods] We selected three sites that are in Suide County of Shaanxi Province, Qinling Mountains in Meixian County of Shaanxi Province and Baiquan County of Heilongjiang Province as the case study areas. A variety of slope classification methods were applied to classify slope. Using the quantitative indicators, we analyzed the spatial pattern and statistical distribution characteristics of slope map.Results] (1) For specific site mapping, quantile or Evans classification method is better; while for comparison of different sites, unified classification scheme is better; (2) Spatial variation decreased dramatically after slope was classified; (3) All slope classification methods lose some slope information; (4) All slope classification schemes were difficult to represent statistical distribution law of slope accurately.Conclusion] (1) The slope surface and natural breakpoint methods are better; (2) With the increase of grading space, slope information declines rapidly in a power function; (3) Statistical distribution of slope is better to be mapped with slope surface and natural breakpoint methods.