=Paper= {{Paper |id=Vol-2665/paper18 |storemode=property |title=Analysis of the accuracy of determining the vegetation edges according to the Landsat remote sensing data over the territory of the Sverdlovsk Region |pdfUrl=https://ceur-ws.org/Vol-2665/paper18.pdf |volume=Vol-2665 |authors=Nina Vinogradova,Andrey Sosnovsky,Stepan Yegorov }} ==Analysis of the accuracy of determining the vegetation edges according to the Landsat remote sensing data over the territory of the Sverdlovsk Region == https://ceur-ws.org/Vol-2665/paper18.pdf
    Analysis of the Accuracy of Determining the
  Vegetation Edges according to the Landsat Remote
  Sensing Data over the Territory of the Sverdlovsk
                      Region
            Nina Vinogradova                                    Andrey Sosnovsky                                                Stepan Yegorov
   Institute of Radio Electronics and                   Institute of Radio Electronics and                            Institute of Radio Electronics and
        Information Technology                               Information Technology                                        Information Technology
        Ural Federal University                              Ural Federal University                                       Ural Federal University
          Ekaterinburg, Russia                                 Ekaterinburg, Russia                                          Ekaterinburg, Russia
        n.s.vinogradova@urfu.ru                                    sav83@e1.ru                                               mr.stepone@mail.ru

    Abstract—The work is devoted to the study of the most                    predominance of wooded ridges and ridges, the other half -
commonly used vegetation indices in relation to the territory of             in the adjacent territories of the West Siberian Plain [2].
the Sverdlovsk region according to Landsat-7 images. For the
image fragments, vegetation maps were constructed using                          Thus, when analyzing vegetation, it must be taken into
various indices. The accuracy was evaluated of the vegetation                account that sown and meadow areas make up no more than
map according to digital topographic maps based on the                       15% of the territory while most of the vegetation indices are
criteria of false alarm errors and missing errors, as well as the            adapted specifically for such types of vegetation.
total number. The indices having the smallest errors are found.              Accordingly, it is necessary to establish which of the existing
Recommendations on the use of indices of vegetative regions                  vegetation indices are optimal specifically for the designated
covered by coniferous and mixed forests are given.                           region.
    Keywords— remote sensing data, vegetation indices, Landsat-                    II. OVERVIEW OF EXISTING VEGETATION INDICES
7, accuracy estimation                                                           There are several commonly used vegetation indices. The
                        I. INTRODUCTION                                      calculation of most of them is based on spectral brightness
                                                                             coefficients for the two most stable regions of the spectral
    Monitoring agricultural and forest land is one of the most               reflection curve of vascular plants - red and infrared bands.
important spheres for using Earth remote sensing data.                       The most common of them is NDVI [3]. NDVI values range
Assessment of vegetation cover is usually carried out using                  from -1 to 1. Along with the NDVI index under conditions
vegetation indices, which can be used for regional mapping                   when vegetation occupies less than 30% of the image, the
and analysis of various types of landscapes, studying the                    RVI index [4] is often used, which range takes values [0, ∞].
dynamics of plant communities. The results of the                            There are also perpendicular vegetation indices (PVI, WDVI,
calculation of vegetation indices are maps of forest and                     DVI [5,6,7]), transformed ones (TVI [8]) and other [8], a list
agricultural land productivity, maps of landscape types,                     of indices used in the work, as well as formulas for their
vegetation and natural zones, and it is also possible to use                 calculation, are given in the table 1.
them to obtain numerical data for use in estimating and
forecasting yields and productivity, biological diversity, and               TABLE I.        THE MAIN VEGETATION INDICES USED IN THE VEGETATION
damage from various natural and man-made disasters,                                                               ANALYSIS
accidents, etc. One of the most popular satellites used to                     Vegetation                                 Vegetati
solve the indicated problems is the Landsat spacecraft system                                    Formula                                      Formula
                                                                                 index                                    on index
[1]. Despite the fact that there is a huge springboard for                                      N IR  R E D 
research in this sphere, most of them relate to the territories                 NDVI                                       DVI                N IR  R E D
                                                                                                N IR  R E D 
of the satellite owner, that is, accordingly, in the United                                         N IR
States, numerous vegetation indices adapted in the first                         RVI                                        PVI      sin   N IR  c o s   R E D
                                                                                                    RED
category for subtropical and tropical climatic zones.                                               N IR
                                                                                 IPVI                                     WDVI             N IR    R E D
    The territory of the Russian Federation is located mainly                                   N IR  R E D 

in the subarctic and temperate climatic zones, naturally, the                                  N IR  R E D         1                   N IR  R E D
                                                                                 TVI                                      SAVI                            (1  L )
problem arises of analyzing vegetation indices as applied to                                   N IR  R E D         2                N IR  R E D  L
the designated territory. The features of the territory of the
Sverdlovsk region, which must be taken into account when
monitoring plant cover, are: a relatively short growing season                   Vegetation maps on the territory of the Sverdlovsk
(up to 130 days per year) with an average duration of snow                   Region (with a total area of 4300 sq. km), located within the
cover of 170 days per year with the accumulation of large                    boundaries of the city of Nizhny Tagil and Gornouralsky city
masses of snow; continental climate; the location is mainly in               district, are based on the Landsat-7 system data. [9]. The
the taiga zone (83% of the territory is covered by forest                    terrain is low-mountainous, the predominant type of
vegetation, 40% of which are pine forests). From the point of                vegetation is coniferous and mixed forests. Date: July 15,
view of the terrain, approximately half of the region’s                      2016. The image fragment is shown in Fig. 1. Ranges for
territory is located on the eastern slope of the Ural Mountains              various vegetation indices were limited according to
(the Middle and partially the Northern Urals) with a                         previously indicated publications [10,11,12].



Copyright © 2020 for this paper by its authors.
Use permitted under Creative Commons License Attribution 4.0 International (CC BY 4.0)
Image Processing and Earth Remote Sensing

                                                                                calculated according to the “tasseled cap” graph (Fig. 2).
                                                                                The angle of the line of soils is 9.7°. It should also be noted
                                                                                that for the SAVI vegetation index, according to the articles,
                                                                                there is uncertainty in the indication of the parameter L,
                                                                                therefore, the need arose to consider it. The results are
                                                                                presented in Fig. 3 and Fig.4. It was found that the right
                                                                                parameter value for the selected area should be equal to
                                                                                0.43.


Fig. 1. The image fragment obtained by Landsat-7 system (true colors).

    To construct the vegetation indices according to table 1,
two Landsat-7 channels were used: № 3 (wavelength is 0.63–
0.68 μm) and № 4 (wavelength is 0.84–0.88 μm). The
calculations were carried out using MATLAB 2018,b.
                             III. RESULTS
    To assess the accuracy of the obtained vegetation maps,
digital topographic maps of scale 1: 200 000 were used,
taking into account the fact that half of the territory is located
on a hilly area, the average error in the contours of areal
objects is equal to 30 m. In general, three types of errors
were calculated: δ1 is the relative missing error (in relation to
the standard) when according to the standard there should be                    Fig. 4. Vegetation maps a) SAVI; b) NDVI; c) DVI; d) PVI.
vegetation, but there is nothing on the vegetation map, and
δ2 is the relative false error when vegetation is present on the                                          IV. CONCLUSION
vegetation map, and on the standard it is absent, as well as                        The most widely used vegetation indices were studied in
the total error δ1 + δ2. The results are shown in table 2.                      relation to the territory of the Sverdlovsk region In the course
                                                                                of the work. It has been found that the most suitable index
                                                                                for the studied fragment of the territory of the Sverdlovsk
                                                                                region is IPVI the total classification error of 19,2 %.
                                                                                Vegetation maps based on indices NDVI (20,2 %), RVI
                                                                                (20.2 %) and SAVI (20,3 %) show slightly worse results. In
                                                                                general, the errors turned out to be quite large, which is due
                                                                                to the systematic deforestation and generally high dynamics
                                                                                of the terrain. In the future, it is planned to carry out a more
                                                                                detailed study of the range boundaries for the space systems
                                                                                of Landsat-7, Landsat-8 and Sentinel-2, corresponding to
                                                                                different types of vegetation, to identify the best vegetation
                                                                                indices in order to adapt them to the specifics of the
                                                                                Sverdlovsk region territory.
                                                                                                         ACKNOWLEDGMENT
Fig. 2. Red and near-infrared scatter chart («the tasseled cap»). The line of       The work was supported by the RFFI grant No.19-29-
soils is shown as dotted line
                                                                                09022\19.
                                                                                                              REFERENCES
                                                                                [1]   LandsatScience [Online]. URL: https://landsat.gsfc.nasa.gov/
                                                                                      (21.12.2019).
                                                                                [2]   Great Russian Encyclopedia. Plant resources [Online]. URL:
                                                                                      https://bigenc.ru/geography/text/5564496/ (23.12.2019).
                                                                                [3]   J.W. Rouse, “Monitoring vegetation systems in the great plains with
                                                                                      ERTS,” Third ERTS Symposium, NASA SP-351, vol. 2, pp.309-317,
                                                                                      1973.
                                                                                [4]   C.F. Jordan, “Derivation of leaf area index from quality of light on
                                                                                      the forest floor,” Ecology, vol. 50, pp. 663-666, 1969.
                                                                                [5]   A.J. Richardson and J.H. Everitt, “Using spectra vegetation indices to
                                                                                      estimate rangeland productivity,” Geocarto International, vol. 1, pp.
Fig. 3. Dependence of the total classification error on a parameter L for             63-69, 1992.
SAVI vegetation map.
                                                                                [6]   J.G.P.W. Clevers, “The derivation of a simplified reflectance model
                                                                                      for the estimation of leaf area index,” Remote Sensing of
   It should be noted that for the PVI and WDVI indices                               Environment, vol. 35, pp. 53-70, 1988.
when constructing vegetation maps, knowledge of the                             [7]   A.J. Richardson and C.L. Wiegand, “Distinguishing vegetation from
position of the line of soils was required, which was                                 soil background information,” Photogrammetric Engineering and
                                                                                      Remote Sensing, vol. 43, pp.1541-1552, 1977.



VI International Conference on "Information Technology and Nanotechnology" (ITNT-2020)                                                                   79
Image Processing and Earth Remote Sensing

[8]  J. Qi, Y.Kerr and A. Chehbouni, “External Factor Consideration in    [11] A.A. Varlamova, A.Yu. Denisova and V.V. Sergeev, “Earth remote
     Vegetation Index Development,” Proc. of Physical Measurements and         sensing data processing for obtaining vegetation types maps,”
     Signatures in Remote Sensing, ISPRS, vol. 1, pp. 723-730, 1994.           Computer Optics, vol. 42, no. 5, pp. 864-876, 2018. DOI:
[9] EarthExplorer [Online]. URL: https://earthexplorer.usgs.gov/               10.18287/2412-6179-2018-42-5-864-876.
     (15.05.2019).                                                        [12] D.E. Plotnikov, P.A. Kolbudaev and S.A. Bartalev, “Identification of
[10] S.A. Bibikov, N.L. Kazanskiy and V.A. Fursov, “Vegetation type            dynamically homogeneous areas with time series segmentation of
     recognition in hyperspectral images using a conjugacy indicator,”         remote sensing data,” Computer Optics, vol. 42, no. 3, pp. 447-456,
     Computer Optics, vol. 42, no. 5, pp. 846-854, 2018. DOI:                  2018. DOI: 10.18287/2412-6179-2018-42-3-447-456.
     10.18287/2412-6179-2018-42-5-846-854.




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