报告时间：2016年7月3日上午10:00-12:00
报告地点：必威betway官网入口遥感betway必威西汉姆联官网报告厅（附3-202）
报告题目：Studying rill/interrill erosion using terrestrial laser scanning: threshold and resolution issues （地面三维激光扫描的土壤侵蚀研究：阈值和分辨率问题）
报告内容： This talk aims to identify the morphologic thresholding of rill-macrorill-gully transformation, and investigate the issue with grid size for rill morphology and measurement of rill/interrill erosion. We used the temporal DEMs produced using TLS to identify the threshold values separating diffusive and convergent erosion/deposition. We then use GIS software programs to generate surface DEMs at 8 different grid cell resolutions (1 cm, 2 cm, 5cm, 8 cm, 10 cm, 15 cm, 20 cm, and 30 cm). A GIS-based approach is applied to delineate rill networks and rill basin boundaries, and topographic factors associated with hydrological process are calculated using the DEMs. We used the 1 cm DEM as the reference to which we compared the calculation output using DEMs of different grid sizes. Our results show that critical threshold values can be identified, and the values possibly indicate a diffusive/convergent separation of erosion/deposition. Erosion at our study site is more sensitive to grid size compared to deposition. The delineation of rill network is not sensitive to grid size, although the offset of rill networks tend to increase as the resolution gets coarser. Determination of the optimal grid size is helpful for standardization of data products, helps the automation of calculations, and improves our knowledge for partitioning of computational power. The result of this study would provide useful reference for future applications of DEM in the study of rill/interrill processes.
报告人简介：陆晓宇，美国田纳西大学地理系博士，研究兴趣包含地理信息系统与遥感技术在地表过程、水资源方面的应用，包括细沟和冲沟水力侵蚀的应用。在中外同行评议期刊发表学术论文十篇，并获得美国国家地理学会地貌学小组“Reds Wolman 优秀研究生奖”、Sigma Xi 科研协会“优秀科研报告”奖。陆晓宇目前是美国国家地理学会、全美地质学会、Sigma Xi等科研组织的成员。
