Extraction Of The Ecotone Between Farmland And Forest Ecosystem Based On Unmanned Aerial Vehicle 3D Photography Technology

The functional and structural features of the ecotone can help to understand the landscape function and process deeply.The study of ecotone offers a breakthrough point to the research of landscape pattern and ecology process.At present,the research of ecological ecotone is mainly based on moving split window analysis,multivariate ordination analysis,spatial statistical analysis and remote sensing geographic information system analysis.These methods can be summarized as the study of community scale and landscape scale.However,the study on the community scale is confined to the lake of random in sampling,and to develop it to the patch scale must set up a large amount of Transects for collecting data.The study on the landscape scale is often based on two-dimensional images which is short of three-dimensional spatial information,or sometimes artificially setting the same threshold for different landscape units that also have limitations.The study on this two scale can't correspond to each other.In recent years,the regional small-scale images can be obtained quickly by unmanned aerial vehicle(UAV)photography technology,and then extract the three-dimensional spatial information.It provides a new way for our research.The purpose of this paper is exploring a method about using UAV photography technology to obtain aerial photograph and then determining the ecotone betw een farmland and forestry ecosystem.In this study,a UAV which carrying a routine digital camera was used for aerial survey of the ecotone between farmland and forestry ecosystem.And the related 3D processing software and GIS software are used for post-processing.Then produced the digital orthophoto map(DOM),digital surface model(DSM),digital terrain model(DTM),the Canopy Height Model(CHM)was obtained by subtracting DSM from DTM.Finally,according to the difference of plant community height between farmland ecosystem and forest ecosystem we can determine the ecotone for landscape mapping and analysis.Meanwhile,generate a 3D landscape model.This paper selected three samples as research cases,we obtained the landscape pattern of sample plots containing ecotone based on UAV aerial photogrammetry technology.The conclusions are as follows:1)Using UAVs carrying ordinary digital cameras to obtain aerial photographs can effectively produce digital orthophoto map,digital surface model.Compared to traditional satellite remote sensing images and DEM data,they have higher resolution and they are more suitable for landscape ecology research in regional scale.2)UAV technology could obtain the plant community height variation of plots.Based on this,we can extracted ecotone between farmland and forest ecosystem.3)the use of UAV technology can not only effectively reduce the working time and work intensity of field operations,but also be able to obtain the whole landscape pattern within ecotone.