摘要
针对基于GIS平台进行斜坡单元划分时,并未考虑栅格分辨率对划分结果的影响,且对填洼阈值及集水面积阈值等关键值缺乏定量的计算方法的问题提出一种斜坡单元划分方法。首先,考虑栅格尺寸的影响,利用Hutchinson提出的坡度中误差法,推求最佳栅格分辨率。计算出DEM中洼地深度,依据真实洼地深度,设置为填洼阈值;根据"沟谷密度-集水面积阈值"关系曲线以及"蓝线"技术推求集水面积阈值;最后,建立较完整的斜坡单元定量划分方法。将此方法运用于实际区域,并进行验证,计算结果表明:斜坡单元划分结果与卫星地形图的山谷(山脊线)的分布较为吻合,能比较规整地体现斜坡的形态和大小。此方法为斜坡单元合理划分提供定量参考,对区域地质灾害风险性评价研究具有现实意义。
The majority of the existing literature has not considered the impact of grid size in the quantitative methods used to calculate the threshold of depression-filling and critical support area. Firstly,the suitable grid size is determined by calculating the root mean square error（ RMSE） of the slope gradient. A threshold of depression-filling is adopted based on the calculated and actual depression-depths. The critical support area is analyzed,in detail,using a curve of drainage density in the critical support area and blue line technology. Finally,we have built a more complete quantitative method for slope unit zoning. Our research method is demonstrated through the application of a slope analysis in Muyu,Shennongjia Forestry District,China. The results show that,the results of the slope unit division are in good agreement with the distribution of the valley（ ridge line） of the satellite topographic map,which can fairly reflect the shape and size of the slope. This study can provide a quantitative reference for the appropriate slope units zoning,and has practical significance for regional geo-hazard assessment.
出处
《自然灾害学报》
CSCD
北大核心
2017年第5期157-164,共8页
Journal of Natural Disasters
基金
国家科技支撑计划课题(2014BAL05B07)~~
