黔中喀斯特筑坝流域水系分维估算与地貌发育特征分析

Fractal dimension estimation and geomorphological character-istics of the water system in the Karst Basin

针对喀斯特地貌发育对筑坝河流径流的影响问题,为了更经济、快捷、精确地提取水系特征,揭示地貌发育对水文特征响应的成因机制,以黔中筑坝区为研究对象,以30 m分辨率的ASTER-GDEM和1∶100万的贵州省综合地貌图为数据源,应用ArcGIS构建渔网法估算流域水系分维,探讨黔中筑坝区水系分维与地貌发育特征的关系。结果表明:(1)通过渔网法估算的北盘江、猫跳河、三岔河、南明河、蒙江、头堡河、翁吟河、鱼梁河、暗流河流域的分维值分别为1.675 6、1.595 1、1.615 1、1.595 0、1.648 9、1.280 2、1.515 1、1.621 6、1.465 1;(2)从地貌发育特征看,研究区主要发育的地貌类型为K化中山谷地、峰丛谷地,占研究区比例为66.9%。北盘江、三岔河、蒙江、鱼梁河流域地貌发育为壮年期,南明河、猫跳河、翁吟河、暗流河流域为幼年期的中晚期,头堡河流域为幼年期的早期;研究区坡度、切割深度的空间展布规律与渔网法估算分维值揭示的地貌发育阶段相一致,与实际发育地貌吻合。

In order to solve the problem of the influence of karst landform development on the runoff of dam-building rivers, the characteristics of water system are extracted by more economical, fast and accurate methods, and the mechanism of the response of geomorphological development to hydrological characteristics is revealed. This paper takes the dam construction area in the middle of the shoal as the research object, the 30 m resolution ASTER-GDEM and the 1 ∶100 000 Guizhou Province comprehensive geomorphology map as the data source, using ArcGIS to construct the fishing net method to estimate the basin water system fractal dimension. The relationship between fractal dimension and geomorphological development characteristics of the water system in the dam area. The result shows that the fractal dimension values of Beipanjiang, Maotenghe, Sanchahe, Nanminghe, Mengjiang, Diebaohe, Wengwei, Yuliang and Underflow river basins estimated by the fishing net method are 1.675 6, 1.595 1, 1.615 1, 1.595 0, 1.648 9, 1.280 2, 1.515 1, 1.621 6, 1.465 1 respectively. From the characteristics of landform development, the main types of landforms developed in the study area are the valleys and peak clusters in the K-type, accounting for 66.9% of the study area. The geomorphology of the Beipanjiang, Sanchahe, Mengjiang and Yuliang river basins is developed into a strong period. The Nanming River, the Maotiao River, the Wenghe River and the Undercurrent River Basin are in the middle and late stages of the infancy, and the Tuobao River Basin is a young year. In the early stage, the spatial distribution law of the slope and cutting depth of the study area is consistent with the developmental stage revealed by the fishnet method to estimate the fractal dimension, which is consistent with the actual development geomorphology.