基于DEM的格尔木河流域数字地形分析

发布时间：2018-04-25 01:08

本文选题：DEM + 流域　；参考：《中国地质大学（北京）》2013年硕士论文

【摘要】：数字地形分析技术的不断深化为地学知识的挖掘和演化提供了良好的发展平台。通过对流域进行数字地形分析，可以提取流域地形地貌及水文特征，并根据不同需要来确定流域分类的关键因子，对亚流域进行分类管理，有利于更详细地了解流域地形，，并获得对流域水系构成的数字化表达，实现流域的可持续发展。通过以格尔木河流域为研究区域，利用30m分辨率的ASTER-GDEM数据，对格尔木河流域进行数字地形分析研究。研究取得了以下主要认识和结论： (1)通过提取格尔木河流域的各种微观和宏观地貌因子，分析了流域地形地貌特征。研究表明：格尔木流域大多数地区坡度都在20°以下，地势较为平缓的地区，坡向分布较均匀；坡度变率的数值范围为0°～30°，整体变化趋势和坡度十分相似。研究区主要以东昆仑山脉为界限，从南向北呈阶梯状递减。 (2)运用ArcGIS的水文分析工具提取了格尔木河流域在不同汇流累积量阈值下的水系河网，并用盒维数法计算相应的水系分维数，得到了在一定无标度区间范围内汇流累积量阈值和分维数的拟合方程，可以快速确定流域河网阈值及相应水系分维数。最后根据分维数大小判断出格尔木河流域处于地貌侵蚀发育壮年期，为流域的复杂地貌形态方面的研究提供了定量依据。 (3)划分出三级水系亚流域盆地，并以Matlab为平台设计了流域水系分维数的计算程序，利用得到的分维值探讨了区域内主要断裂构造的活动性强弱。分析表明北侧东昆中断裂的整体活动性差异不大，西大滩断裂和东昆南断裂则以昆仑山垭口附近为界，西侧断裂活动性逐渐增强，东侧则均由弱变强再变弱。 (4)利用SPSS软件对亚流域的典型河流地貌参数进行主成分分析，通过简化区域地貌—水文系统的要素维数，剔除了相关性较大的因子，保留了亚流域的主要特征。再根据新生成的主成分依照各个样本的相似测度算出各流域在各主成分上的得分值，最后根据各得分值间的欧式距离进行流域系统聚类分析研究，从而得到相似流域，以期实现无资料地区的参数转移。
[Abstract]:The deepening of digital terrain analysis technology provides a good development platform for the mining and evolution of geoscience knowledge. Through the digital terrain analysis of the watershed, the topographic and hydrological characteristics of the watershed can be extracted, the key factors of watershed classification can be determined according to different needs, and the subbasin can be classified and managed, which is helpful to understand the watershed topography in more detail. The digital expression of the river system is obtained to realize the sustainable development of the river basin. By taking the Golmud River Basin as the research area and using the 30m resolution ASTER-GDEM data, the digital terrain analysis of the Golmud River Basin is carried out. The main findings and conclusions of the study are as follows: 1) by extracting various microcosmic and macroscopic geomorphological factors of Geermu River Basin, the topographic and geomorphological characteristics of the basin are analyzed. The results show that the slope is below 20 掳in most areas of Geermu Basin, and the slope direction distribution is more uniform in the gentle terrain area, and the value range of slope variation rate is 0 掳~ 30 掳, and the overall variation trend is very similar to the slope degree. The study area is mainly east Kunlun Mountains as the boundary, from south to north a ladder decline. (2) using the hydrological analysis tool of ArcGIS, the river network of Geermu river basin under different confluence accumulative threshold is extracted, and the corresponding fractal dimension of river system is calculated by box dimension method. The fitting equations of the cumulative confluence threshold and the fractal dimension in a certain scale-free range are obtained. The threshold of river network and the fractal dimension of the corresponding river system can be determined quickly. Finally, according to the fractal dimension, it is concluded that the Geermu River basin is in the mature period of geomorphological erosion, which provides a quantitative basis for the study of complex geomorphology in the basin. In this paper, the subbasin of tertiary drainage system is divided, and the program of calculating the fractal dimension of drainage system is designed on the platform of Matlab. The activity of the main fault structures in the region is discussed by using the obtained fractal dimension. The analysis shows that there is little difference in the overall activity of the Dongkunzhong fault on the north side, while the Xidatan fault and the Dongkunnan fault are bounded by the Kunlun Mountain pass. The activity of the west fault increases gradually, and the east side of the fault becomes weak again. (4) using SPSS software, the main component analysis of typical river geomorphological parameters in the subbasin is carried out. By simplifying the element dimension of the regional geomorphology and hydrological system, the correlation factors are eliminated and the main characteristics of the subbasin are preserved. According to the newly generated principal components, the score of each watershed on each principal component is calculated according to the similarity measure of each sample. Finally, according to the Euclidean distance between the obtained values, the basin system cluster analysis is carried out, and the similar watershed is obtained. In order to realize the parameter transfer in the area without data.
【学位授予单位】：中国地质大学（北京）
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：P208

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