黄土丘陵沟壑区侵蚀地形空间频率层次性研究

项目名称： 黄土丘陵沟壑区侵蚀地形空间频率层次性研究

项目编号： No.41301284

项目类型： 青年科学基金项目

立项/批准年度： 2014

项目学科： 天文学、地球科学

项目作者： 王春梅

作者单位： 西北大学

项目金额： 26万元

中文摘要： 地形强烈影响了土壤侵蚀强度，在区域尺度土壤侵蚀研究中，地形因子一般通过中低分辨率DEM提取，其提取结果受DEM分辨率的影响较为明显。针对该问题，前人就地形要素与分辨率关系进行了一系列研究，但已有研究多针对地形指标统计特征值（如坡度平均值）与分辨率的关系进行分析，对机理认识不足。本项目针对地形因子受分辨率影响的原因这一科学问题，通过分析DEM表面地形信息的空间结构特征，将地形空间结构特征与地形空间频率的高低联系起来，应用地统计，尤其是独立结构变异函数模型，构建侵蚀地形空间频率层次性表达模型；结合野外调查、高分辨率遥感影像的判读，对模型的合理性进行论证；基于该模型模拟不同复杂程度地貌类型区、多种分辨率条件下的地形空间频率特征，阐明地形因子随分辨率变化的机理。本研究对于促进地形因子尺度效应研究、丰富完善数字地形分析理论体系、改进土壤侵蚀评价精度有重要的理论意义。

中文关键词： 数字高程模型；分辨率；尺度效应；空间频率；地统计

英文摘要： Terrain influnces soil erosion intensively. Terrain factors are mainly extracted from coarser resolution DEMs nowadays in regional soil erosion research. And terrain factors are influnced by the resolution obviously. Researchers studied the relationship between terrain factors and resolution. However, these researches are mainly about the relationship between statistics of terrain (for example 'mean slope') and resolution, and there is a lack on the mechanistic explanations about this. This study is mainly about this topic. In this research, the spatial structures of terrain surface will be analysed based on DEM, and the spatial frequency(lower frequency and higher frequency for example) will be linked to the spatial structures of terrain surface. Geo-statistics method especially the Independent Structures Model(ISM) will be used to model the terrain spatial frequency characteristics. And field survey, high resolution images will be used to give the reasonableness check of the model. And the model will be applied in varied terrain areas and DEMs with seris of resolutions to give the spatial frequency characteristics of terrain surface in order to show the mechanistic explanations about the influnce of resolution to terrain factors.This study may help on the research of terrain scaling, rich the study of digital

英文关键词： DEM；Resolution；Scalling Effect；Spatial Frequency；Geostatistics