Blog

Short title: characteristicScale.lsc

Inputs: A DEM (the Baranja Hill 25m DEM is used as an example). The name of the parameter to measure and the minimum and maximum window sizes over which to measure it.
Outputs: Two rasters, one containing the measured parameter, the other the window size at which the parameter is most extreme.

Purpose and use:

Finds the scale at which a geomorphometric parameter is most extreme for each cell in a DEM. Part of this script appears in Hengl and Reuter (2008) [the Geomorphometry book].
Script to measure surface parameter at characteristic scales. It is designed to incorporate scale-based analysis into surface parameterisation. It measures the given parameter (e.g. slope, profile curvature etc.) at a range of scales, and finds the scale at which that parameter is most extreme. Can be used to explore scale sensitivity of a surface.

Programming environment: Landserf
Status of work: Public Domain
Reference: Geomorphometry: Concepts, Software, Applications
Data set name: Baranja hill

Attachment:

characteristicScale.lsc_.zip

Maunga Whau (Mt Eden) is one of about 50 volcanos in the Auckland volcanic field. This data set gives topographic information for Maunga Whau on a 10 m by 10 m grid. A matrix with 87 rows and 61 columns, rows corresponding to grid lines running east to west and columns to grid lines running south to north.

Perspective view - volcano

Available layers:

- volcano_maungawhau.asc — the 10 m DEM digitized from the topo map;

Grid definition:

ncols: 61
nrows: 87
xllcorner: 2667400
yllcorner: 6478700
cellsize: 10 m

proj4:+init=epsg:27200

Lineage:

Digitized from a topographic map by Ross Ihaka. These data should not be regarded as accurate.

\> data(volcano)
>library(spatstat)
>LLC <- data.frame(E=174.761345, N=-36.879784)
>coordinates(LLC) <- ~E+N
>proj4string(LLC) <- CRS("+proj=longlat +datum=WGS84")
>LLC.NZGD49 <- spTransform(LLC, CRS("+init=epsg:27200"))
>volcano.r <- as.im(list(x=seq(from=2667405, length.out=61, by=10),
+     y=seq(from=6478705, length.out=87, by=10), 
+     z=t(volcano)\[61:1,\]))
>volcano.sp <- as(volcano.r, "SpatialGridDataFrame")
>proj4string(volcano.sp) <- CRS("+init=epsg:27200")
# str(volcano.sp)
# spplot(volcano.sp, at=seq(min(volcano.sp$v), max(volcano.sp$v),5),
+    col.regions=topo.colors(45))
>write.asciigrid(volcano.sp, "volcano\_maungawhau.asc", na.value=-1)

Data owner: LINZ
Location:Volcano Maungawhau, Auckland, New Zealand
36° 50’ 50.586” S,174° 45’ 56.646” E
See map: Google Maps

Attachment:
volcano_maungawhau.zip

Short title: landform

Inputs: Digital Elevation Model, classification parameters.
Outputs: Map showing landform classes according to Pennock and Corre (2001).

Purpose and use:

Landform Classification based on method of Pennock and Corre (2001). Classify landform units based on relief parameters provided using the topo.aml. Original Source are papers by Pennock et al., Rewritten in aml as closely as possible. Requirements: topo.aml, killgrids.aml, logoff.aml

Programming environment: Arc AML
Status of work: Public Domain
Reference: Geomorphometry: Concepts, Software, Applications

Short title: DEMsim

Inputs: control.txt - 1020 precise measurements (photogrametric + spot heights); elevations.txt - 2051 points (contours + spot heights); dem10m_tin.asc - 100x150 pixels 30m DEM.
Outputs: simulated DEMs, simulated error surfaces, error assessment statistics.

Purpose and use:

Script to generate and simulate DEMs and assess the error of the height measurements. Prepared for the needs of a research paper ‘Geostatistical modelling of topography using auxiliary maps’. Please consider testing the script before you use it with large datasets.

Programming environment: R / S language
Status of work: Public Domain
Reference: {Geostatistical modelling of topography using auxiliary maps}
Data set name: Zlatibor

Attachment:

zlatibor-1.zip

Short title: g_landf

Inputs: %1 - table with central values has to have same domain as the class map, %2 standard fuzziness factor (1.5), %3 - domain, %4 - SLOPE, %5 - PLANC and %6 - ACV.
Outputs: membership values (0-1) to each generic landform (stream, ridge, slope, plain, pit and peak)

Purpose and use:

Extracts six generic landforms (stream, ridge, slope, plain, pit and peak).

Programming environment: ILWIS
Status of work: Public Domain
Reference: Geomorphometry: Concepts, Software, Applications

g_landforms.zip