The model presented in this paper derives toposequences from a digital elevation model (DEM). It is written in ArcInfo Macro Language (AML). The toposequences are called kth-order random toposequences, because they take a random path uphill to the top of a hill and downhill to a stream or valley bottom from a randomly selected seed point, and they are located in a streamshed of order k accordin...

This paper presents a method for predicting areas at risk from dryland salinity using information derived from multi-temporal Landsat TM satellite images combined with landform data derived from high-quality digital elevation models. The method is applied in the south west agricultural region of Western Australia to predict areas at risk from dryland salinity. This paper presents modifications ...

Water level (WL) and water volume (WV) of surface-water bodies are among the most crucial variables used in water-resources assessment and management. They fluctuate as a result of climatic forcing, and they are considered as indicators of climatic impacts on water resources. Quantifying riverine WL and WV, however, usually requires the availability of timely and continuous in situ data, which ...

This document describes a capstone learning exercise designed for undergraduates enrolled in an introductory geospatial tools course. The overarching theme of the exercise, Colorado 14ers, Pixel by Pixel, is mountain geography. While immersed in a digital mountainous landscape, students explore topics of geomorphology and geomorphometry and discover how it is possible for a summit that rises we...

Terrain patterns play an important role in determining the nature of water resources and related hydrological modelling. Digital Elevation Models (DEMs), offering an efficient way to represent ground surface, allow automated direct extraction of hydrological features (Garbrecht and Martz, 1999), thus bringing advantages in terms of processing efficiency, cost effectiveness, and accuracy assessm...

In the paper is described the process of creating digital terrain models (DTM) using different interpolation methods. The analyses show the accuracy of the DTM obtained from topographic maps at different scales and using different interpolation methods. The quality and accuracy of DTM depends on the complexity of the terrain, data sources, and methods of height interpolation. The basic idea is ...

Large gradients, when calculated by a first-difference method, have been detected in the 9 arc-second National Digital Elevation Model (DEM) of Australia released by the Australian Surveying and Land Information Group. Gradient values implied by the mean elevations in the DEM between adjacent grid cells of up to 74° have been observed, most notably in Australia’s more mountainous regions in the...

A solar 3D urban model was developed for the calculation and visualisation of the solar energy potential of buildings, integrating the potential of roofs with that of facades. To assess this potential, a digital surface model (DSM) of the urban region was built from LiDAR data and a solar radiation model based on climatic observations was applied. A shadow algorithm was developed in order to ca...

The construction of inter-visibility models for a terrain is an important tool for environmental and animal studies. E-cient crisp algorithms are known to address this problem directly on a raster digital elevation map (DEM) of the study area. Randomness plays an important role: several factors like vegetation, height of the observer, presence of unmapped human artifacts, etc. cannot be modeled...