DOI: 10.5061/dryad.tx95x6b7k
title: Land cover of the lower Amazon floodplain, ca. 2008-2009

description: Land cover of the lower Amazon floodplain ca. 2008-2009 was mapped at 30 m
 resolution using a combination of multi-temporal Landsat Thematic Mapper
 (TM) and ALOS PALSAR-1 data.  To enable mapping of seasonal
 changes in lake and channel areas, map inputs included TM scenes acquired
 at very low, mid, and high stage levels of the Amazon River. Land cover
 classes mapped were open water (with separate classes for the Amazon
 mainstem channel and floodplain lakes and channels), "campo" (3
 classes), shrub, and forest. "Campo" refers to seasonally
 flooded areas that transition among bare ground, herbaceous, aquatic
 macrophyte, and open water states. Campo areas were further divided
 between those flooded at  low-, mid-, and high-water levels.
 Excluding the main stem channel, the primary  land cover in the
 study region was seasonally inundated lakes and channels (59.4%), followed
 by permanently inundated lakes and channels (17.9%; these retained water
 even at extreme low water stage), seasonally  inundated shrub
 (17.1%), and seasonally inundated forest (5.6%).  Seasonally
 inundated lakes and channels may be further subdivided into those flooded
 at an average low water stage (27.5%), at an average mid-water stage
 (59.6%), and at an average high-water stage (12.9%). Renó et al.
 (Assessment of deforestation in the Lower Amazon floodplain using
 historical Landsat MSS/TM imagery. 2011. Rem. Sens. Envmt.
 115(12):3446-3456) estimated that 56% of the floodplain forest cover in
 the study area was lost between the late 1970s and 2008, and that 78% of
 that deforested area was replaced with non-forest vegetation,
 bare/herbaceous, or open water habitats primarily as a result of clearing
 for jute plantations and cattle ranching, with smaller areas lost to
 channel erosion. We compared 1995 JERS-1 imagery with resampled ALOS
 PALSAR imagery for 2007 in order to estimate changes in land cover during
 our study period.  The net change from forest habitat to clearing
 or water (15.2%) was almost exactly balanced by areas transitioning from
 clearing to forest (15.0%).  These results indicate that over
 those 20 years, deforestation and regrowth were more or less balanced, and
 forest coverage was relatively stable, albeit much lower than in the
 pre-colonial era. Our map of floodplain habitats provides input for
 scientifically informed policy that incorporates ecological knowledge,
 human economic decision-making, and climate-driven hydrologic variability.
 The mapped area extends from 57W, 1.4S to 52.9W, 3S and is provided in
 GeoTiff and Esri shapefile formats.
description: Mapping was carried out for the floodplain of the lower Amazon
 River (referred to locally as várzea) within a17,674 km² study area in
 Pará State, Brazil. Wetlands within a 10 km buffer of the floodplain were
 also mapped. The study area contains a mosaic of forests, lakes, and
 secondary channels that are continually re-shaped by dynamic processes of
 erosion and sedimentation. The várzea supports diverse plant communities,
 with herbaceous and shrub communities occurring near margins of lakes and
 channels, and forests occupying higher ground along natural levees. The
 annual river flood pulse as measured at the Óbidos gauge is monomodal and
 varies by 4 to 8 m annually (mean variation of 5.7 m), creating marked
 differences in floodplain conditions between high-water periods, when most
 areas are flooded, and low-water periods when only lakes and connecting
 channels retain water.  The river water level begins to rise during
 December and reaches its maximum during late May or early June. Water
 level starts to fall during August, reaching its minimum during
 November. Land cover ca. 2008-2009 was mapped at 30 m
 resolution using a combination of multi-temporal Landsat Thematic Mapper
 (TM) and ALOS PALSAR-1 data.  To enable mapping of seasonal changes in
 lake and channel areas, map inputs included TM scenes acquired at very
 low, mid, and high stage levels of the Amazon River. Land cover classes
 mapped were open water (with separate classes for the Amazon mainstem
 channel and floodplain lakes and channels), "campo" (3 classes),
 shrub, and forest. "Campo" refers to seasonally flooded areas
 that transition among bare ground, herbaceous, aquatic macrophyte, and
 open water. Campo areas were further divided between those flooded at 
 low-, mid-, and high-water levels. The forest category includes tall
 forest remnants (with emergent canopy heights to 40 m), regenerating
 forests (locally termed capoeiras) and pioneer forests, the latter two
 categories having lower and more variable canopy heights. The shrubby
 aroid <em>Montrichardia spp.</em>, 1 to 4 m in height, often
 dominates pioneer forests in areas of low elevation and was included
 within the forest category. ALOS PALSAR data
 (fine-beam, 7 swaths) was acquired during the early rising water period
 (late December to mid-January) in each of the years 2007, 2008, 2009,
 2010, and 2011 (Dec 2006 - Jan 2007 is counted as 2007, etc.). Macrophytes
 can occur within the Campo, WtrOther, or WtrMstem habitat types and are
 quite variable from year to year. Macrophyte area in this region
 consistently peaks during the early rising water period. Since PALSAR
 imagery was not consistently available for other seasons, early rising
 water presence/absence was mapped as an indicator of macrophyte spatial
 and temporal variation. Along and within the Amazon
 mainstem channel, erosion and deposition were mapped by comparing land
 cover in 2008-2009 with that ca. 1995-1997 (based on Landsat TM and JERS-1
 imagery). All classifications were carried out in
 Ecognition, using byte-transformed versions of Landsat TM Tasseled Cap
 Brightness/Greenness/Wetness, fine-beam dual-pol ALOS PALSAR-1, and the
 SRTM DEM to segment at multiple scales before an object-based
 classification using polygon metrics and relationships to neighboring
 objects. Contemporaneous QuickBird images were used as training
 data. Details of input imagery and class coding are
 given in LowerAmazonFloodplainLandCoverInputsLegends.xlsx.
  
description: # Land cover of the lower Amazon floodplain, ca. 2008-2009
 [https://doi.org/10.5061/dryad.tx95x6b7k](https://doi.org/10.5061/dryad.tx95x6b7k) ## Description of the data and file structure These analyses were funded by NASA Land-Cover and Land-Use Change program grant NNX12AD27G (L. Hess and D. McGrath, PIs): Land and resource use on the Amazon floodplain under evolving management systems and environmental change: Fish, forests, cattle, and settlements. Land cover classes were selected to emphasize habitats relevant for fish abundance and biodiversity, and fisheries productivity. ### Files and variables #### LowerAmazonFloodplainLandCoverBW\.tif, \*.tfw Single-band byte GeoTiff (UTM, zone 21S, WGS 84, (EPSG:32721), 30 m pixels) with DN codes for land cover classes. The data range is 0 to 240.  See README_LowerAmazonFloodplainLandCover.xlsx for further documentation. #### LowerAmazonFloodplainLandCoverColor.tif, \*.tfw Three-band byte GeoTiff (UTM, zone 21S, WGS 84, (EPSG:32721), 30 m pixels) with DN codes for land cover classes. Displays color-coded map in RGB. The data range is 0 to 255.  See README_LowerAmazonFloodplainLandCover.xlsx for further documentation. #### LowerAmazonFloodplainLandCover.shp, \*.shx, \*.dbf, \*.prj Esri shapefile corresponding to LowerAmazonFloodplainLandCoverBW.tif. #### LowerAmazonFloodplainMacrophyteDec-Jan2007-2011.tif, \*.tfw Five-band byte GeoTiff (UTM, zone 21S, WGS 84, (EPSG:32721), 30 m pixels) with DN codes for aquatic macrophyte presence/absence. The data range is 0 to 255.  Bands 1 to 5 correspond to 2007, 2008, 2009, 2010, 2011. See README_LowerAmazonFloodplainLandCover.xlsx for further documentation. #### LowerAmazonFloodplainMacrophyteDec-Jan2007-2011MultiYearCount.tif, \*.tfw Single-band byte GeoTiff (UTM, zone 21S, WGS 84, (EPSG:32721), 30 m pixels) with DN codes for aquatic macrophyte presence/absence. The data range is 0 to 192.  See README_LowerAmazonFloodplainLandCover.xlsx for further documentation. #### LowerAmazonFloodplainErosionDepositionColor.tif, \*.tfw Three-band byte GeoTiff (UTM, zone 21S, WGS 84, (EPSG:32721), 30 m pixels) showing areas of erosion and deposition along the Amazon mainstem channel, 1995-2009. Displays color-coded map in RGB. The data range is 0 to 255. See README_LowerAmazonFloodplainLandCover.xlsx for further documentation. #### LowerAmazonFloodplainErosionDeposition.shp, \*.shx, \*.dbf, \*.prj Esri shapefile corresponding to LowerAmazonFloodplainLandCoverErosionDeposition.tif. #### LowerAmazonFloodplainBoundary.shp, \*.shx, \*.dbf, \*.prj Esri shapefile showing Amazon floodplain boundary with the study region, Amazon River channel, and wetlands/uplands within a 10 km buffer of the floodplain (UTM, zone21S, WGS84). ## Code/software GeoTiff and Esri shapefiles can be viewed using QGIS (any version; open software), as well as in commercial image processing or GIS software. ## Access information Other publicly accessible locations of the data: * Data was derived from the following sources: * See README_LowerAmazonFloodplainLandCover.xlsx.