DOI: 10.5061/dryad.wstqjq314
title: Relative Terrain Height DEM transform for the mid-Juruá region, Brazilian Amazon

description: The Relative Terrain Height (RTH) is a novel DEM transform that
 facilitates 1) minimizing regional terrain height differences when
 comparing elevations of distal floodplain features; 2) optimizing terrain
 data for input to image segmentation algorithms; and 3) delineating
 boundaries of terrain features such as floodplains, fluvial terraces,
 interfluvial flats, and hillslopes. An example of RTH is given for a 2° x
 2° area including the mid-Juruá region of the Brazilian Amazon, derived
 from the Copernicus GLO-30 Digital Elevation Model (DEM), at a resolution
 of 30m. The transform is based on differencing versions of the input DEM
 at 30 m (the original resolution) and 3000 m (resampled again to 30 m).
 The resulting RTH layer reflects the height of a feature relative to its
 surroundings, while retaining the detail of the original DEM, and the
 transform can easily be produced using any image processing software. The
 RTH is provided in GeoTIFF format. The input data set used to produce the
 RTH data product was the Copernicus WorldDEM-30.
description: The Copernicus GLO-30 DEM (https://doi.org/10.5270/ESA-c5d3d65; obtained 2020-11-20) was downloaded for the region 3.5° - 6.5° S to 65.5° - 68.5° W, and transformed to the Universal Transverse Mercator projection (UTM Zone 19S) at 30 m resolution; a buffer of 0.5° was added from adjoining tiles to avoid creation of artifacts at the boundaries of the study region, which extends from  4° - 6° S to 66° - 68° W. The 30 m DEM was resampled to 3000 m pixels (i.e., by a factor of 100) using weighted average resampling, then resampled back to 30 m using cubic convolution resampling. The original 30 m layer and the twice-resampled layer were next co-registered, and the twice-resampled layer was subtracted from the original DEM. The resulting Relative Terrain Height (RTH) layer was then cropped to the original DEM tile extent.
description: # Relative Terrain Height DEM transform for the mid-Juruá region,
 Brazilian Amazon Dataset DOI:
 [10.5061/dryad.wstqjq314](https://doi.org/10.5061/dryad.wstqjq314) ##
 Description of the data and file structure The Relative Terrain Height
 (RTH) digital elevation model (DEM) transform was developed to facilitate
 terrain type mapping, land cover mapping, and analysis of floodplain
 forest structure in relation to floodplain topography in the mid-Juruá
 region (western Brazilian Amazon). RTH is a relative measure, in meters,
 of DEM height relative to the surrounding terrain. The RTH dataset is for
 a 2° x 2° area extending from 4° - 6° S to 66° - 68° W. The work was
 carried out under grants from the Belmont Forum (via the U.S. National
 Science Foundation) and Fondation BNP Paribas (via Institut de Recherche
 pour le Développement). ### Files and variables ### File:
 midJurua_GLO-30_RTH_UTM19S_30m_32bit.tfw **Description:** Standard GeoTIFF
 header file for midJurua_GLO-30_RTH_UTM19S_30m_32bit.tif #### File:
 midJurua_GLO-30_RTH_UTM19S_30m_32bit.tif **Description:** Relative Terrain
 Height (RTH) product for study area including the mid-Jurua region
 (Brazilian Amazon) in GeoTIFF format File format: Single-band GeoTIFF,
 32-bit File size: 7418 columns X 7399 rows Coordinate reference system
 name: EPSG:32719 - WGS 84  / UTM zone 19S (Universal Transverse Mercator)
 Coordinate reference system units: meters Pixel size: 30 m Upper left UTM
 19S coordinate: 610669.566E, 9557830.0S Data value units: meters Data
 value meaning: Relative Terrain Height in meters (height relative to
 surrounding terrain, using the RTH transform described in the Methods
 section). Data range: -40.2057 to 39.7468 meters ## Code/software The
 GeoTiff files can be viewed with free software such as QGIS. The final
 product is derived using generic image processing functions such as image
 resizing and image co-registration, as described in the Methods. ## Access
 information Other publicly accessible locations of the data: * N/A Data
 was derived from the following sources: * The RTH data product was
 produced using Copernicus WorldDEM-30. The Copernicus GLO-30 DEM can be
 downloaded at
 [https://doi.org/10.5270/ESA-c5d3d65](https://doi.org/10.5270/ESA-c5d3d65)