Research On The Application Of UAV Photogrammetry In River Demarcation

The management and protection line demarcation of rivers,lakes and water conservancy projects is a necessary basic work to strengthen the management of rivers and lakes and water conservancy projects in the new period.With the passage of time,the river boundary will be affected by natural and human factors such as flood scouring,man-made occupation and construction.Therefore,it is very necessary and urgent to carry out regular river and lake boundary survey for the rapid,accurate and efficient river and lake boundary and river rights confirmation and other river management.With the development of new surveying and mapping technology,the traditional surveying method has been unable to meet the needs of the new river delimitation work,the traditional method is time-consuming and laborious,and the cost is relatively high,and in some mountain sections the risk is also relatively large.So it is imperative to adopt the new technology of UAV photogrammetry.Compared with the traditional method,UAV photogrammetry has the advantages of short time and convenient operation,and greatly reduces the difficulty and intensity of field workers.However,due to the application of UAV photogrammetry technology in water conservancy projects and river right confirmation in recent years,there are still some technical problems to be studied and solved.In this paper,the modern UAV photogrammetry technology is applied to the project based on the demarcation project of Jialing River channel management line and protection line.Firstly,the composition,classification and the principle of data acquisition and processing of UAV low altitude photogrammetry system are summarized.Secondly,combined with the requirements of the project to design the UAV large scale mapping process;Analyzing and verifying the accuracy of the later differential PPK assisted aerial triangulation and related mapping requirements,as well as the key technology of producing the Jialing River topographic map by combining the image data processing software PIX4DMapper and the geographic information acquisition software Space Vision MapMatrix.The accuracy of DOM,DEM and DLG generated by UAV photogrammetry was analyzed.The experimental results show that the quality of the Jialing River topographic map based on the "Xianfeng" UAV photogrammetry is qualified and can be used for the delimitation of the Jialing River.Finally,the "once-in-a-decade" flood level line of Jialing River is analyzed and calculated based on the relevant hydrological data,and the management and protection scope lines of Jialing River are delimited.