The software LandLord 4.0 is intended for digital terrain modelling and geomorphometric studies.
Initial data are digital elevation models (DEMs) based on plane square grids and spheroidal equal angular grids.
The software LandLord 4.0 allows one to carry out the following procedures:
· Derivation of digital models of local topographic variables. Four methods can be used to process DEMs based on a plane square grid: the Evans–Young method, the Zevenbergen–Thorne method, the Shary method, and the IF-2009 method. The IF-1998 method can be used to derive partial derivatives from DEMs based on a spheroidal equal angular grid. One can calculate the following characteristics describing the geometry of the topographic surface in the vicinity of a given point on the surface:
§ All variables of the complete system of curvatures: horizontal (or tangential) curvature, vertical (or profile) curvature, mean curvature, Gaussian curvature, accumulation curvature, ring curvature, unsphericity curvature, difference curvature, minimal curvature, maximal curvature, horizontal excess curvature, and vertical excess curvature.
§ Other local morphometric variables, such as slope gradient, slope aspect, northwardness, eastwardness, rotor, Laplasian, plan curvature, shape index, curvedness, horizontal curvature deflection, vertical curvature deflection, and others.
§ Models of landscape classification using four schemes: the Gauss, the Efremov–Krho, the Shary, as well as accumulation zone ones.
· Derivation of digital models of nonlocal morphometric variables. The Martz–De Jong method is used to process DEMs based on a plane square grid. This method adapted to the geometry of the convex spheroidal equal angular grid is used to process DEMs based on a spheroidal equal angular grid. One can calculate the following characteristics describing a relative position of a given point on the topographic surface:
§ Minimal and maximal catchment area.
§ Minimal and maximal dispersive area.
· Derivation of digital models of solar morphometric variables. These variables can be derived from DEMs using methods for the calculation of local variables (see above). One can calculate the following characteristics describing relations between the topographic surface and solar irradiation in the vicinity of a given point of the topographic surface:
§ Reflectance (Lambertian and other models).
· Derivation of digital models of combined morphometric variables. These variables are derived from DEMs by the sequential application of methods for nonlocal and local variables (see above), followed by an arithmetic combination of the results. One can calculate the following characteristics considering both the local geometry of the topographic surface and a relative position of a point on the surface:
§ Minimal and maximal topographic index.
§ Minimal and maximal stream power index.
· Smoothing of digital models based on square-spaced and spheroidal trapezoidal grids:
§ Weighted average smoothing using 3 x 3, 5 x 5, and 7 x 7 kernels.
§ Calculating depression-free DEMs by the Martz–De Jong method.
· Some of the simplest mathematical operations with morphometric models: addition, subtraction, multiplication, division, logarithming, exponentiation, as well as area and volume estimation.
· Statistical analysis:
§ Derivation of linear regression-based digital models of natural properties using topographic attributes as independent variables in corresponding regression equations.
§ Estimation of root mean square errors (RMSE) for all variables of the complete system of curvatures as well as slope gradient, slope aspect, plan curvature, rotor, and derivating function derived from DEMs given by square-spaced and spheroidal trapezoidal grids.
· Visualization of DTMs using several colour and grey scales (examples can be found in publications).
· Import of Surfer binary files *.grd
· Import of quasi-global and global DEMs: ETOPO1, ETOPO2, ETOPO5, GLOBO, GTOPO30, SRTM30, SRTM30_PLUS, SRTM15_PLUS, GEBCO, IBCAO, IBCSO, SRTM3, SRTM1, ASTER GDEM, and AW3D30, as well as planetary DEMs from NASA PDS archives.
· Export of LandLord DTM files into plain text files, ArcInfo text files *.asc, and Surfer binary files *.grd.
Availability and distribution
I do not distribute the software. A collaborative research with a subsequent joint publication is the only possibility to use LandLord 4.0.
For details and examples, see: