基于近景摄影测量的植物裸露根系三维建模与分析

Three-Dimensional Modeling and Analysis of Exposed Roots Based on Close-Range Photogrammetry

摘要: 坡面植物根系裸露会影响坡地地表径流流路和土壤侵蚀过程，然而裸露根系分布特征差异大，与表层土壤形成不同的空间格局，制约了裸露根系影响侵蚀特征的进一步研究。因此本研究结合近景摄影测量技术，借助AgisoftMetashape Professional和ArcGIS软件对裸露根系进行了亚厘米级的高精度三维建模，用于提取裸露根系的长度、面积和分布方式。结果表明：1) 在非接触和非破坏的方式下，近景摄影测量技术能够精准、高效地对野外的裸露根系进行特征提取；2) 生成的高清晰度影像非常适合亚厘米级以下裸露根系的提取分析；3) 研究中裸露的纵向根系在长度和面积上均占据主导地位(占比均超过50%)，在进行室内模拟根系裸露对土壤侵蚀的影响过程中，可以按照纵向、横向和斜向根数量依次递减的顺序布置根系。本研究为进一步研究裸露根系与土壤侵蚀的互馈机制提供了良好理论基础。

Abstract: The exposed roots of plants on slope will affect the paths of the surface runoff flow and soil erosion process of slope land. However, the distribution characteristics of exposed roots are quite different, and different spatial patterns are formed with surface soil, which restricts the fur-ther study of the influence of exposed roots on erosion characteristics. Therefore, this study com-bined with close-range photogrammetry, AgisoftMetashape Professional and ArcGIS, sub-centimeter-level high-precision three-dimensional modeling of exposed roots was carried out to extract the length, area and spatial distribution characteristics. The results showed that, 1) In a non-contact and non- destructive way, close-range photogrammetry can accurately and efficiently extract the characteristics of exposed roots in the field; 2) The generated high-resolution images were very suitable for the extraction and analysis of exposed roots below sub-centimeter level; 3) The exposed vertical roots were dominant in length and area (accounting for more than 50%) in this study. In the process of indoor simulation of the effect of exposed roots on soil erosion, the roots could be arranged in the order of decreasing number of vertical, horizontal and oblique roots. This study provides a good theoretical basis for further study of the interaction mechanism between ex-posed roots and soil erosion.