Hengl & Reuter poster at Geomorphometry.org/2011


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A proposal for a global database with DEM-derivatives.

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Hengl & Reuter poster at Geomorphometry.org/2011

  1. 1. An open database of DEM-derivatives of the WorldT. Hengl & H.I. ReuterGlobal DEM-derivatives Proposed implementationThe idea of a global repository of DEM-derivatives is not new. USGS has The database needs to guarantee the following five criteria (Hengl & Reuterbeen maintaining the global 1 km HYDRO1k (http://eros.usgs.gov) --- a 2008):repository of DEM derivatives (elevation, WTI, slope, aspect, flow direction,flow accumulation, drainage basins and streams). San Diego Supercomputer Precision --- It needs to provide the best estimates of surface measures andCenter hosts a project called "Open Topography" objects, derived from the most accurate and current data and al-(http://opentopography.org/) that aims at serving high resolution (LiDAR) gorithms.data and tools. Esri™ will build and host a collection of multiresolution DEM Multiscale --- Input DEM need to reside within a multi-scale GIS so that it canderivatives, starting with SRTM and analytic services against it, as well as be available at various resolutions.higher resolution DEM derivatives for places where the data is freelyavailable. The data will all be available for free on ArcGIS.com. Open structure --- Users should be able to modify and adjust spatial queries to tailor surface measures and objects to fit specific needs. Web access --- The system should provide a high performance cached map services and interactive analytic functions as web services (e.g. viewshed and watershed delineation). Quality --- the input (DEMs) and algorithms should be continually evaluated and improved and maintained to ensure their fitness for use (minimum artifacts). Spatial query GEOMORPHOMETRIC ATLAS Thematic properties DEM - LSP/LSOs type - algorithms - pre-processing steps Function library Spatial properties - coordinate system - spatial resolution *Activate functions LSPs / matching the best - extent (boundaries)Fig. 1: An example of a complete topographic model of the world at resolution of 1 km. For more info LSOs with users’ request according to the see: http://commons.wikimedia.org/wiki/File:Globedem.png organizer criteria WEB-INTERFACEOn the other hand, it is difficult for asingle investigator or even one group toundertake complex geomorphometry on a New data Outputsglobal scale --- instead, cooperative type dateinitiatives (such as thegeomorphometry.org) are needed. Fig. 3: Conceptual design for a geomorphometric atlas: a user definesAn open database of DEM- various parameters and then downloads the data. Processing and derivation of surface descriptors is done directly on the server.derivatives LSP/LSO = Land Surface Parameters/Objects.We propose here initiation of open Conclusionsdatabase of DEM derivatives (a geo-morphometric atlas) --- an international Demand for DEMs and their derivatives, evident from many differentnetwork of mirrored servers that will host disciplines and applications, will prompt ever higher expectations for rigorthe largest collection of DEM derived and force the global scientific community to commit to an ongoing review ofproducts including reference methods, data standards. The Global DEM-derivatives initiative is a platform forsoftware tools and standards. meeting these expectations. Fig. 2: The landform classification followingSuch geo-database would support the Iwahashi and Pike (2007). Relief classes References: which are classified using an unsuperviseddevelopment of knowledge libraries, as nested-means algorithms. Hengl, T., Reuter, H.I. (eds) 2008. Geomorphometry: Concepts, Software, Applications. Developments in Soil Science, vol. 33, Elsevier, 772 pp.well as continued testing and comparison Kleiner, K., 2011. Data on demand. Nature Climate Change 1, 10–12.of geomorphometric methods by the scientific community (Kleiner, 2011). Iwahashi, J. and R. J. Pike, 2007. "Automated classifications of topography from DEMs by an unsupervised nested- means algorithm and a three-part geometric signature." Geomorphology 86(3-4): 409-440.ISRIC - World Soil Information, Wageningen UniversityPO Box 353, 6700 AJ Wageningen, the NetherlandsURL: http://www.isric.orgE-mail: {tom.hengl; hannes.reuter}@wur.nl