【作者】 周毅；

【导师】 汤国安；

【作者基本信息】 南京师范大学 ， 地图学与地理信息系统， 2011， 博士

【摘要】 正负地形(Positive and Negative Terrains)是地球表面最具宏观统治力的二元地形结构。本文在分析黄土地貌正负地形结构特征的基础上,以沟沿线发育明显的晋西-陕北-陇东地区正负地形为切入点,基于地学信息图谱和数字地形分析理论,以均匀分布的86个样区为空间分异研究样区,以典型黄土地貌下多级嵌套流域为尺度序列研究样区,以1：1万比例尺数字高程模型为基本数据源,系统性的提出并阐述了黄土地貌正负地形概念模型、属性特征及分布特点,发现黄土地貌正负地形具有宏观抽象、区域差异、地貌对应、多要素性等地学特性,深入探讨了其图谱性质,并基于黄土地貌正负地形研究晋西-陕北-陇东黄土高原地貌宏观特征及其空间分异规律,在此基础上,基于多尺度分割分析方法,实现了研究区内正负地形特征的区域划分。论文的主要内容和结论如下：1.明确了黄土地貌正负地形概念模型。在分析黄土坡而结构及沟道发育特征的基础上,归纳了黄土地貌正负地形的基本特性,阐述其广义和狭义定义,并构建了正负地形分类体系。2.利用改进snake模型,设计了基于高分辨率DEM的正、负地形自动分割的方法。该方法立足于数字地形分析思想,基于黄土坡面形态特征,首先识别沟沿线点,继而利用改进的snake模型实现沟沿线断点的自动连接,从而实现正负地形的自动划分。3.构建正负地形特征量化指标体系并分析了指标间相关性。分别从地貌演化特征、地形统计特征和空间展布特征三个角度提出并构建了正负地形的量化指标体系(共10个),在此基础上分析了指标间的相关性。4.实现了晋西-陕北-陇东黄土地貌正负地形空间分异分析。基于86个样区正负地形因子,利用GIS空间插值方法,制作了研究区内10个正负地形特征空间分异专题地图,特别是正负地形面积对比指标——蚕食度指标的空间分异专题地图,并利用多尺度分割方法,基于相关性不显著的5个因子层面,实现了正负地形特征的区域划分,最后结合区划结果对正负地形因子进行了指标的厘定5.黄土地貌正负地形在描述黄土高原宏观地貌特征上表现出较大的优势与潜力。本文所构建的正负地形概念模型和研究方法体系,是黄土高原地表形态空间分异自然规律发现的有效切入点,丰富了黄土高原地区数字地形分析方法体系,是地学信息图谱分析思想的有益实践,是黄土高原地区水保措施制定的重要参考依据。更多还原

【Abstract】 Loess Positive and Negative Terrains are the most macroscopic dualistic components of the earth’s surface. The Loess Positive and Negative Terrains (P-N terrains), which are widely distributed on the Loess Plateau, are discussed in this paper by introducing its characteristic, demarcation, distribution rules as well as extraction method. Using 5 m-resolution DEMs (scale is 1:10000) as original test data, P-N terrains of 86 geomorphological units in different parts of west Shanxi, north Shaanxi and east Gansu Loess Plateau are extracted accurately by using of an improved Snake model method. Then ten indicators (Nibble Degree, Proximity Distance, Mean-slope Difference, Inciensiveness, Mean-Roughness-Ratio, Shape Index, Moran’s Index, Evenness Index, Fragmentation, Fractal Dimension) for depicting the landform evolution, spatial configuration and geomorphologic landscape characteristics of P-N terrains are proposed, and the correlation between the indicators are discussed also. Ten thematic maps which describing the spatial variation of P-N terrains are made by using of the GIS spatial interpolation method. The spatial distribution rules of these indicators and the relationship between the P-N terrains and Loess relief are discussed for further understanding of Loess landform. Finally, with the integration of P-N terrains indices, a series of multi-scale segmentation classification methods are applied to make a proper classification which reflecting the features of positive and negative terrain well in the study area. Zonal statistics showed that nibble degree is 0.423 in loess tableland and tableland ridge area,0.826 in loess ridge area and 1.041 in area of loess hill and hill-ridge area. Results show that P-N terrains are an effect clue to reveal energy and substance distribution rules on the Loess Plateau. A continuous change of P-N terrains from south to north in Shaanxi Loess Plateau shows an obvious spatial difference of Loess landforms. This research is significant on the study of Loess land forms with the Digital Terrains Analysis methods, and is an important reference for the development of water conservation measures in the Loess Plateau.更多还原