冀西北间山盆地区切沟断面特征分析

Analysis on the Characteristics of Gully Cross Section in the Basin of Northwest Hebei Mountains

切沟侵蚀是冀西北山盆地间的主要侵蚀方式之一,断面形态是反映切沟发育程度的关键特征。为分析切沟断面形态表征,通过三维激光扫描仪获取了研究区切沟的三维坐标数据,统计并分析切沟重要参数信息。研究结果表明:(1)研究区内切沟宽度大小差异较大,但沟深相差较小,切沟断面变异系数反映出了同一断面位置不同参数的离散程度;(2)所有切沟从沟头到沟口,底宽/顶宽(α)逐渐减小,70%以上的侵蚀沟的三个断面位置都是U型沟,有近30%的切沟存在着U型、V型和U-V型沟之间的转变;(3)切沟各断面位置的宽深比频率中有50%的切沟宽深比数值集中在1~2范围内;(4)研究区切沟的平均顶宽值和平均沟深值相比其他研究区而言均最大,而平均宽深比最小。该研究结果是进一步对切沟形态特征讨论,分析切沟体积和发育趋势的科学基础。

Gully erosion is one of the main erosion modes in the Basin of Northwest Hebei Mountains, and the cross-sectional morphology is a key feature of the degree of gully development. In order to analyze the morphological characterization of gully section, the three-dimensional coordinate data of gullies in the study area were obtained by three-dimensional laser scanner, and the important parameter information of gullies was counted and analyzed. The results show that(1) the width of the gully varies greatly in the research area, but less depth of gullies. The coefficient of variation of trench section reflects that, the dispersion degree of different parameters at the same cross section position of gullies.(2)All gullies from the head to the middle to the bottom/top width of the gully(α) gradually decreases, more than 70% of the erosion gully are U-shape, and nearly 30% of the gullies have a transition between U-shape, V-shape and U-V-shape.(3)The width and depth ratio frequency statistics of the gully head, middle and outlet positions showed that 50% of the gully width and depth ratio values were concentrated within the 1~ 2 range.(4)The average top width and average gully depth of the gully in this research area are the largest compared with other research areas, while the average width depth ratio is the smallest compared with other research areas. Compared with other study areas, the average top width and average gully depth of the gully in this study area are the largest, and the average width depth ratio is the smallest. This research result is a further discussion of gully morphological features, analyzing the scientific basis of gully volume and developmental trends.