Blog

Geomorphometry followers may be interested in the new version of my TauDEM (Terrain Analysis Using DEMs) software available from http://hydrology.usu.edu/taudem.

TauDEM is free and open source. It comprises a set of Digital Elevation Model (DEM) tools for the extraction and analysis of hydrologic information from topography as represented by a DEM.

The new version, TauDEM 5.0 takes advantage of parallel programming using the message passing interface (MPI) and achieves improved runtime efficiency and the capability to run larger problems.

TauDEM includes functions for the development of hydrologically correct (pit removed) DEMs, calculation of flow paths, contributing area, stream networks and other flow related derived information. Its unique features are that it uses the D-Infinity flow model for evaluation of information derived from dispersed flow over hillslopes and provides objective methods for the determination of stream network delineation thresholds.

The parallel version (TauDEM 5.0) has been completely restructured as a set of command line functions in standard C++ using MPICH2. The source code has been compiled for both PC’s and parallel clusters. GeoTiff is used as the input/output file format so that the command line functions that provide core functionality are platform independent. TauDEM does include an ArcGIS toolbox Graphical User Interface (for ArcGIS 9.3.1) that has been recoded to use system calls to these command line executables.

The development of TauDEM 5.0 was supported by the US Army Engineer Research and Development Center under contracts W9124Z-08-P-0420 and W912HZ-09-C-0112.

This dataset contains a series of x,y,z LiDAR point cloud data in csv format, delimited by comma. Points are projected in the NC State Plane EPSG 3358 coordinate system with units meters.

To get more better representation of structures from LiDAR surveys,
re-interpolate to 0.3-0.5m resolution using the available external point clouds nc_coast_pointseries.zip.

Available layers:

• “JR_NED_*” - 1/3 and 1/9-Arc Second National Elevation Dataset (2 m);
• “ortho_JR_*” - Time series of ortho photos (1932, 1945, 1955, 1974, 1988, 1998, 2007, 2009);
• “JR_*.csv” - Time series of point clouds from LiDAR (1974, 1995, 1996, 1997, 1998, 1999, 2001, 2005, 2007, 2008, 2009)

Grid definition:

min max
x 912884 914112
y 250049 250905

cellsize: 2 m
cells.dim: 614 by 428

proj4: +proj=lcc +lat_1=36.16666666666666 +lat_2=34.33333333333334 +lat_0=33.75 +lon_0=-79 +x_0=609601.22 +y_0=0 +ellps=GRS80 +units=m +no_defs

Lineage:

All other data sets are from lidar, but the coverage varies, some data sets cover only beach and foredune area and do not include the main dune. Date of the surveys is in the name of of the file in the form YYYY_MM_DD.

Data owner: USGS / NCSU
Reference: Landscape dynamics from LiDAR data time series
Location: NC, United States
35° 57’ 41.148” N, 75° 37’ 49.152” W
See map: Google Maps

Attachment:

nc_coast_pointseries.zip

JR_maps

JR_2009_11_27

JR_2008_03_27

JR_2007_07_08

JR_2005_11_26

JR_2004_09_25

JR_2001_02_15

JR_1999_11_04

JR_1999_09_18

JR_1999_09_09

JR_1998_07_01

JR_1997_10_02

JR_1996_10_16

JR_1995_07_01

JR_1974_07_01

The 4th international conference + workshops on Geomorphometry / Digital terrain modelling and analysis will be held next year in Nanjing, China. If you have not done already, put this date in your agenda: October 16-20, 2013 (Wednesday to Sunday). We expect again an exciting programme with several workshops and training sessions. This edition of Geomorphometry is kindly sponsored by the Geographical Society of China, National Natural Science Foundation of China, Key Laboratory of Virtual Geographical Environment, Ministry of Education, and Nanjing Normal University. For all other info please refer to www.geomorphometry.org/meetings/nanjing-2013/

Colleagues from ESRI are actively producing geomorphometry tools and data sets for public use. This is an example of a multiscale slope map built using the ArcGIS JavaScript API. The ESRI’s World Elevation Services is expected to become fully operational in mid 2012. It will contain image services, data download services, and analysis task services available, as well as sample applications.

Google has recently released a Google Elevation service. The Elevation service provides SRTM/bathymetry elevation data for locations on the surface of the earth, including depth locations on the ocean floor (negative values). It can be used to produce elevation paths and get elevations for any point on Earth’s surface (maximum of 2,500 requests per day).

Have you missed the Geomorphometry 2011 conference? No problem. All presentations from Geomorphometry 2011 are available via the ESRI proceedings website. All papers and attached datasets can also be accessed freely from the Geomorphometry homepage.

TanDEM-X is the new generation satellite (owned by the German Aerospace Center) that aims at producing new generation radar-based DEMs with a horizontal detail of 12 meters) and a height accuracy of better than 2 m. The data will likely not be publicly available, but the new global DEM will completely change the world of geomorphometry. http://www.dlr.de/hr/en/desktopdefault.aspx/tabid-2317

A recent geography Master’s thesis by Jason Goetz from the University of Waterloo, Canada utilizes terrain analysis tools implemented in open-source software (SAGA GIS, R) for exploring the regional controls of landslide initiation on Vancouver Island, British Columbia. A nonparametric regression technique, the generalized additive model (GAM), was used to model the relationship of topography, climate, forest harvesting activities and geology to landslide initiation, underlining the importance of the impacts of logging roads. Based on the model predictions, the most susceptible 4% of the study area had 29 times higher density of landslide initiation points than the least susceptible 73% of the study area,

Attachment e_democracy_2011.xls

Following our geomoprhomerty.org 2011 conference in Redlands we created a group called geomorphomerty at arcgis.com. The objective is to facilitate and engage a larger community of people around the world outside geomorphometry.org, especially esri users as well as the general GIS community.

Group members can create and share maps within the group and to the public as well. As a start a selection of global landforms maps are displayed, which will be expanded in the future.