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UID:pretalx-foss4g-2022-academic-track-GDD8XU@talks.osgeo.org
DTSTART;TZID=CET:20220825T093000
DTEND;TZID=CET:20220825T100000
DESCRIPTION:Lake Maggiore and the Ticino River are water bodies shared by\n
 Italy and Switzerland: they are important resources for drinking\nwater\, 
 irrigation and hydroelectricity generation as well as for\ntourism and bio
 diversity. The cross-border character and the\noften conflicting needs of 
 the different users make the shared\nmanagement of this resource very comp
 lex\, but of great importance.\nThe `‘Parchi Verbano Ticino´’ project
 \, funded by Regione\nLombardia / EU – INTERREG Italia Svizzera 2014/202
 0\, aims\nto study the effects of water levels of the lake on various envi
 ronmental\ncomponents with a particular focus on protected\nnatural areas.
  The level of the lake is regulated by a dam located\nat the southern shor
 e of the lake. In this framework\, this\nstudy aims to analyse the effect 
 of water level on bird migration\nby: 1) Calculate the inundated bird habi
 tat using a simulation\nbased on measured water level\; 2) calculate the i
 nundated habitat\nfrom Sentinel-1 remote sensing imagery 3) Use the floode
 d\narea derived from S1 as ground truth to validate the previous\nsimulati
 on 1).\nThe study area is centerend around Bolle di Magadino (Switzerland\
 ,\n8°51’56.90”E\, 46°9’42.17”N\, a protected wetland located\non
  the north shore of lake Maggiore at the confluence with the\nTicino river
 . The area is a recognized nesting and stopover\nsite for birds\, listed a
 s a Ramsar Wetland of International Importance\nand as Important Bird and 
 Biodiversity Area (IBA).\nWe defined the habitats of interest  using\na ve
 getation map provided by Fondazione Bolle di Magadino.\nThe vegetation typ
 es collected from a phytosociological field\nstudy were aggregated into te
 n land cover classes that described\nthe habitat types and land use. The f
 inal habitat map covers\nan extent of 6.7 km²\, including the 1500 ha of 
 wetland called\nBolle di Magadino. Daily passage of migrant birds have bee
 n\nrecorded at Magadino ringing station and since 2019\, traditional\nnet 
 captures were coupled with an Avian Vertical-looking Radar\nIn this study 
 we focus on the following periods\, during which\nbird monitoring systems 
 were both deployed: P1: 2019-05-01–\n2019-06-20\; P2 2019-10-01–2020-0
 2-20 and P3 2021-02-01–\n2021-07-20.\nThe lake level measured at the hyd
 rological station of Locarno\n(CH) was used to determine the inundated are
 a in GRASS GIS\nusing ther.fill module (GRASS Development Team\, 2022) and
 \na DTM that included the lake bathymetry (cell size 0.5 m). The\nlake lev
 el fluctuated between 192.3 and 194.9 m.a.s.l. over the\nstudy period\, wi
 th a minimum in April and May\, when the waters\nare used to irrigate the 
 rice fields downstream\, and a maximum\nin late autumn.\n\nWe used the Goo
 gle Earth Engine Platform (GEE) (Gorelick et\nal.\, 2017) to extract Senti
 nel-1 Synthetic Aperture Radar (SAR)\nimages (ESA\, 2021) as they are suit
 ed for surface water mapping\nand not affected by cloud coverage (Ovakoglo
 u et al.\, 2021).\nWe used Edge Otsu Algorithm with terrain correction (Ma
 rkert\net al.\, 2020) to estimate the inundated areas of the collection of
 \na total of 236 images for the three time periods when bird migration\nwa
 s also monitored. The calculation was implemented\nGEE with the approach d
 escribed by Gorelick et al. (2017) calibrating\nthe threshold for our stud
 y area\, adapting the code provided\nby Open Geo Blog (2021). The inundate
 d areas were then\noverlapped with the land use map in order to estimate t
 he extent\nof the submerged vegetation over the three time period defined.
 \nThe resolution of all maps was 10 m\, except the DTM that has\n0.5 m\, t
 he CRS used in this work were WGS84 in GEE and the\nlocal CRS GCS CH1903 f
 or all the other analysis.\nThe area covered with water\, according to S1\
 , varied between\n103.9 and 471.7 ha (210+- 83.6)\, some of the surface is
  a permanent\nwetland so it is never completely dry. Each habitat was\naff
 ected differently by the flooding: when the water was at its\nhighest\, cr
 oplands were completely inundated\, grasslands and\nreeds were submerged f
 or 80% of their extent whereas urban\nareas and infrastructures were not a
 ffected (less than 1% underwater).\nThe flooded area calculated by filling
  the terrain model\nat the level of the ranged from 130.4 to 248.90 ha (20
 8+- 48.6).\nThe correlation between inundated areas obtained using r.fill 
 in\nGRASS and S1 on the same dates was fair for P1 and P2\, but\nnot for P
 3\, when the water of the lake were taken for irrigation\,\nbut the habita
 ts were flooded by rainfall. An interpolation of the\nflooded from S1 is a
  more efficient way to obtain an estimate of\nthe flooded habitat on a dai
 ly basis\, that is necessary to study\nits effect on migratory birds.\nThe
  results presented here will contribute to the definition sustainable\nman
 agement tools of water management of lake Maggiore\ntaking into account th
 e effect of lake level on biodiversity\nin general and on bird habitat in 
 particular.
DTSTAMP:20260413T210748Z
LOCATION:Room Modulo 3
SUMMARY:Effect of water level on bird habitat at lake Maggiore - Clara Tatt
 oni
URL:https://talks.osgeo.org/foss4g-2022-academic-track/talk/GDD8XU/
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