Analysis Of Urban Wetland Vegetation And Landscape Based On Low-level UAV Remote Sensing

Urban wetland is an important component of urban ecology and urban landscape.In the process of planning and construction of urban wetland, some problems such as the acquisition means of wetland spatial information is not applicable.Low efficiency and lack of understanding of wetlands and science is not rigorous etc. River is the cradle of human civilization,as a unique wetland, river wetland has attracted people's attention. There are more construction of urban wetland landscape based on rivers.In this article take the Shenyang Puhe Wetland as the object of study. Select two different kinds of typical and representative wetlands:one is natural wetland and one is manual wetland.Wetland distribution in the less human activity areas, with centralized traffic inconvenience even slices, and so on. Therefore,this study use Low-altitude unmanned aerial vehicle remote sensing technology to get the remote sensing images,combined with the ground vegetation survey to analyze the space and wetland vegetation for two samples.To reveal the differences between the natural wetland vegetation and artificial landscape wetland vegetation.Providing scientific basis for ecological landscape planning of urban wetland in the future.Results were as follows:Adopting TianXun AS 1200 low level UAV to obtain the image, then using Pix4D mapper software to correct and joint the image, obtaining high resolution remote sensing image which spatial resolution is 4.88cm, then conducting vegetation surveys base on this image.2.Based on the shape, color, texture, position and other image features to divided the sample segment space into six types,including natural water, riparian zone, farmland, swamp, artificial pond, artificial green space.Based on the shape of vegetation, shadow and size etc to distinguish the different types of wetland vegetation community.Combining different plant of texture, color to underline the distribution boundaries of different vegetation formations, using Arc GIS9.3 to divide and statistic the image.3.Determine the species composition and structure of the wetland plant community, draw the distribution map of wetland vegetation through the process of RS image and combine with the results of wetland vegetation ground survey, Compare and analyze the results from the two samples:(1)In the wetland spatial aspects, like natural water in Natural urban wetlandssample14.33%, riparian zone 9.22%, Marsh 46.13%, farm 17.11%, pond 4.36%. Landscape urban wetlands of natural waters in area of 31.47%, riparian zone 10.02%, Marsh 14.08%, farm 5.06%, landscape 38.91%.(2)In terms of plant species composition, there are 60 species belonging to 20family 38 genera in sample I.Including 23.68% grass,10.57% Compositae, Chenopodiaceae, nymphaeaceae, Polygonaceae, Cyperaceae, Salicaceae, all above 5%. There are 57 species, belonging to 30 family 47 genera in sample II.,grass 10.64%,10.64% Compositae, Rosaceae, 6.38%. Landscape urban wetlands increased the betulaceae, Crassulaceae, Malvaceae, Sonko, Elm branch, Cruciferae, Aceraceae and other vegetation, the lack of the Ling family, nymphaeaceae, Scrophulariaceae and other wetland vegetation.(3)In terms of wetland plant life-form, in Natural urban wetlands sample perennial 43.33%, annuals 33.33%, an annual or perennial herb 10%, trees at least 1.67%.In Natural urban wetlands sample perennial 36.84%, annuals 24.56%, an annual or perennial herb 12.28%, tree 17.54%.(4)In terms of ecological wetland plants, most wetland plants in the sample paragraph I, accounting for 35% of the total, followed by aquatic plants 26.67%,25% plants, Xeric plants, 13.33%. Vegetation distribution of transition from land as water environments, is on the rise in the number of plant species. Wetland plants in Landscape urban wetlands and xerophytic plants are 29.82%, followed by plants in 28.07%, aquatic plants and 12.28%.(5)In the area of wetland plant communities, Natural urban wetlands sample Zizania latifolia covers a total area of 16.47%, the Phragmites australis 14.63%, community of Nymphaea L.9.53%, Polygonum Orientale Linn, communities in the East 4.47%, Echinochloa crusgalli (1.) Beauv. communities 2.32%, Populus canadensis Moench 2.14%,and,Euryale ferox community 1.63%. Landscape urban wetlands in large patches of the plant communities of wetland Phragmites australis community 13.11%, Typha angustifolia communities 5.04%. But they still have difference between the same plant species composition and structure of plant communities in two sample.