Climate Change Data Portal
| 应用地面立体摄影测量研究金字塔沙丘形成发育动态过程 | |
| 项目编号 | 49501014 |
| 张伟民 | |
| 项目主持机构 | 中国科学院寒区旱区环境与工程研究所;中国科学院西北生态环境资源研究院 |
| 开始日期 | 1996 |
| 结束日期 | 1998-12-01 |
| 中文摘要 | 【中文摘要】将地面立体摄影测量首次应用于复杂沙丘类型的形成机制研究，并采用风洞实验与野外沙丘沉积构造测量相结合的研究，使沙丘动力学过程比以往研究更为全面、系统、有效。其次，建立了金字塔沙丘近地表剪切风速分布规律，提出了敦煌莫高窟顶金字塔沙丘是多信风条件下产生的主、副臂的不同组合，金字塔沙丘发育的环境动力条件须在两组或两组以上风向，夹角介于30-120?局地环流是造成金字塔沙丘总体运移趋势的重要动力条件，通过对金字塔沙丘近地表流场、沉积构造解析分析，认为金字塔沙丘是链状沙丘的一种变形、分离形式。同时，对金字塔沙丘进行了为期二年的监测，对沙丘的整体蚀，积规律进行了较为详细的研究。本项研究不仅有助于揭示金字塔沙丘形成发育动力机制，更重要的是，将为今后综合整治莫高窟风沙危害提供了科学理论依据。 【英文摘要】Internal structures, near-surface airflow surveys and grain size analysis are conducted on a pyramid dune, and the movement of the pyramid dune is monitored by using photogrammetry. An attempt is made to clarify the dynamic development processes of pyramid dunes through studies combining wind tunnel tests and field survey. Some main conclusions are made. (1) Variable wind directions have considerable significance in the development of the pyramid dunes. The occurrence of erosion and deposition of a ridge depends upon the angle between the wind direction and crest line. The study has shown that when the intersection angle between airflow direction and dune crest line is over 30 a reverse vortex forms. Sands accumulate there, causing the ridge’s vertical growth. Though longitudinal airflow plays a very important role in the longitudinal evolution of arms, no deposition is induced on the arms directly by the longitudinal airflow. (2) Monitoring of the pyramid dune from 1972 to 1985 showed that the whole body of the dune migrated in the NE direction, particularly the upper quarter section of the dune. the resultant local circulation, markedly affects the migration of the pyramid dune. The results of wind tunnel experiments and field observations also show that asymmetry of two slopes of a ridge can significantly influence the evolution of ridges of pyramid dunes. (3) Comparing the effects of airflow transverse to a given arm with longitudinal airflow, it is indicated that the transverse airflow is more significant in controlling the arms of pyramid dunes. The migration rates of pyramid dunes are mediated by the interplay of their arms moving transversely and the vertical growth in response to the variations in wind regimes. It is believed that pyramid dunes are much possible particular assemblages of transverse dunes according to the processes of forming the main and secondary arms. (4) The originals in the study are to monitor pyramid dune by using photogrammetry, and the integrated study methods including field observation of dune, sedimentary structure, and wind tunnel simulation experiments to probe the dynamical processes of the pyramid dunes, and to set up distributive pattern of shear velocity near surface of a pyramid. |
| 中文关键词 | 地面立体摄影测量 金字塔沙丘 敦煌莫高窟 形成发育机制 |
| 英文关键词 | pyramid dune;Mogao Grottoes;photogrammetry;near-surface airflow;monitoring dune migration |
| 学科分类 | 0801 - 地理学;08 - 地球科学 |
| 资助机构 | CN-NSFC |
| 项目经费 | 100000 |
| 项目类型 | 青年科学基金项目 |
| 国家 | 中国 |
| 语种 | 中文 |
| 来源机构 | 中国科学院西北生态环境资源研究院 |
| 文献类型 | 项目 |
| 条目标识符 | http://gcip.llas.ac.cn/handle/2XKMVOVA/195399 |
| 作者单位 | 中国科学院寒区旱区环境与工程研究所;中国科学院西北生态环境资源研究院 |
| 推荐引用方式 GB/T 7714 | 张伟民.应用地面立体摄影测量研究金字塔沙丘形成发育动态过程.1996. |
| 条目包含的文件 | 条目无相关文件。 | |||||
| 个性服务 |
| 推荐该条目 |
| 保存到收藏夹 |
| 导出为Endnote文件 |
| 谷歌学术 |
| 谷歌学术中相似的文章 |
| [张伟民]的文章 |
| 百度学术 |
| 百度学术中相似的文章 |
| [张伟民]的文章 |
| 必应学术 |
| 必应学术中相似的文章 |
| [张伟民]的文章 |
| 相关权益政策 |
| 暂无数据 |
| 收藏/分享 |
除非特别说明，本系统中所有内容都受版权保护，并保留所有权利。
