长白山火山区放射状水系分形特征研究

Researches of Fractal Features of Radial River System in the Changbaishan Volcanic Area

水系分维反映了水系的发育程度,体现了河道的复杂程度.以TM遥感数据和分形几何理论为基础,应用图像分析软件ENVI对长白山火山区水系进行了盒维数计算,经统计分析得到了该区四个子区域水系及整个区域水系的分维数.结果表明:长白山火山区水系分维数西部最大D=1.425,东部最小D=1.212;四个分区分维数的差异直接反映了其流域地貌侵蚀发育的程度,但从整体上来看仍处于河流地貌发育的初级阶段.流域地貌的发育状态与火山地形、火山活动及其形成的断裂构造、块体运动以及下覆地面岩性有关,其中断裂构造是最主要的.

The values of fractal dimension of river system reflect their degree of development and complexity of river channel.On the basis of remote sensing data,fractal geometry and image analysis software,the values of box-counting fractal dimension for the radial river system of Changbaishan volcanic area are calculated,and carried out statistical calculations in EXCEL.The region can be subdivided into four distinct areas characterized by different geomorpholo-gic features and their values of fractal dimension also can be obtained respectively.The results show that the maximum value D=1.425 of fractal dimension of river system in the Changbai-shan volcanic area appears in the west part of volcanic area while the minimum D=1.212 in the eastern part.The differences of fractal dimension values of the four distinct areas show the erosive degree of the fluvial landform,but in the whole,the degree of development is still in the primary stage.The contributing factors of fluvial landform are related with volcanic topography,volcanic activities and their forming fracture,mass movement and rock of underlying surface,among which the fracture is main.