受图像的空间分辨率和反立体现象等因素的影响,单纯基于二维遥感图像提取冲沟参数精度较低。以山东省栖霞市庵里水库东岸流域为研究区,建立一种地形和遥感图像融合技术,并用于提取沟沿线、坡底线等冲沟参数,以期为沟蚀参数的大量、快速提取提供一种新方法。结果表明:①基于HSV变换,高斯标准化地表粗糙度作为地形图像融合的权重,建立了地形与遥感图像融合方法,增强和丰富了图像中的地形信息。②基于融合数据,结合沟沿线和沟底线坡度阈值处理,在研究区内提取了144条冲沟,总面积为1.699 km2,占流域总面积的29.89%,为强烈侵蚀。③选择张家沟—北丁家沟流域作为检验区,以RTK-GPS实测数据为参照,地形融合法提取冲沟的准确率和沟头平均偏移量分别为98.413%和4.12 m,其精度明显高于传统的遥感图像目视解译法(73.016%和9.61 m)。
Due to factors such as image scale and the False Topographic Perception Phenomenon (FTPP)in remote sensing images, the accuracy of gully interpretation using traditional single remote sensing images is low. Using the eastern watershed of Anli reservoir in Qixia, Shandong province, as a study area, we propose an improved surface-roughness- weighted HSV transformation method to combine topographic maps and images into a fusion image that can be used to map the shoulder-line and thalweg of gullies. This technique provides a new method for gully erosion research and has yielded the following results. (1) Based on HSV conversion and weighting via Gaussian standardizing surface roughness, the fusion method enhances and enriches the topographic information in the remote sensing image. (2) Based on the fusion image and the slope threshold of the shoulder-line and thalweg of gullies, 144 gullies were extracted in the study area. The gullies covered an area of 1.699 km2 (or 29.89% of the total drainage area), indicating that the study area is seriously eroded. (3) Based on RTK-GPS field measurements, the identification accuracy of gullies and the mean offset between the interpreted gully head (fusion method) and the field measurement were 98.413% and 4.12 m, respectively, which were significantly higher and lower, respectively, than those of the traditional single remote image technique (73.016% and 9.61 m, respectively).