https://www.clw.csiro.au/aclep/documents/McBratney%20et%20al.%202003.pdf

On digital soil mapping

https://cyberleninka.org/article/n/352063.pdf

87Sr/86Sr, δ13C and δ18O evolution of Phanerozoic seawater

Landslide hazard evaluation: a review of current techniques and their application in a multi-scale study, Central Italy

The Mars Orbiter Laser Altimeter (MOLA), an instrument on the Mars Global Surveyor spacecraft, has measured the topography, surface roughness, and 1.064-μm reflectivity of Mars and the heights of volatile and dust clouds. This paper discusses the function of the MOLA instrument and the acquisition, processing, and correction of observations to produce global data sets. The altimeter measurements have been converted to both gridded and spherical harmonic models for the topography and shape of Mars that have vertical and radial accuracies of ~1 m with respect to the planet's center of mass. The current global topographic grid has a resolution of 1/64° in latitude × 1/32° in longitude (1 × 2 km^2 at the equator). Reconstruction of the locations of incident laser pulses on the Martian surface appears to be at the 100-m spatial accuracy level and results in 2 orders of magnitude improvement in the global geodetic grid of Mars. Global maps of optical pulse width indicative of 100-m-scale surface roughness and 1.064-μm reflectivity with an accuracy of 5% have also been obtained.

/pdf/mars-orbiter-laser-altimeter-experiment-summary-after-the-3w1byzpn90.pdf

Mars Orbiter Laser Altimeter: Experiment summary after the first year of global mapping of Mars

A model for the topographic influence on shallow landslide initiation is developed by coupling digital terrain data with near-surface through flow and slope stability models. The hydrologic model TOPOG (O'Loughlin, 1986) predicts the degree of soil saturation in response to a steady state rainfall for topographic elements defined by the intersection of contours and flow tube boundaries. The slope stability component uses this relative soil saturation to analyze the stability of each topographic element for the case of cohesionless soils of spatially constant thickness and saturated conductivity. The steady state rainfall predicted to cause instability in each topographic element provides a measure of the relative potential for shallow landsliding. The spatial distribution of critical rainfall values is compared with landslide locations mapped from aerial photographs and in the field for three study basins where high-resolution digital elevation data are available: Tennessee Valley in Marin County, California; Mettman Ridge in the Oregon Coast Range; and Split Creek on the Olympic Peninsula, Washington. Model predictions in each of these areas are consistent with spatial patterns of observed landslide scars, although hydrologic complexities not accounted for in the model (e.g., spatial variability of soil properties and bedrock flow) control specific sites and timing of debris flow initiation within areas of similar topographic control.

/pdf/a-physically-based-model-for-the-topographic-control-on-3babhrnl49.pdf

A physically based model for the topographic control on shallow landsliding

Mathematical proof establishes identity of hypsometric integral and elevation-relief ratio, two quantitative topographic descriptors developed independently of one another for entirely different purposes. Operationally, values of both measures are in excellent agreement for arbitrarily bounded topographic samples, as well as for low-order fluvial watersheds. By using a point-sampling technique rather than planimetry, elevation-relief ratio (defined as mean elevation minus minimum elevation divided by relief) is calculated manually in about a third of the time required for the hypsometric integral.

Elevation-Relief Ratio, Hypsometric Integral, and Geomorphic Area-Altitude Analysis

Slope failure and shoreline retreat during northern California's latest El Nino

Automated classifications of topography from DEMs by an unsupervised nested-means algorithm and a three-part geometric signature

The transition from small simple craters to large complex or modified craters is characterized by eleven changes in the shape of fresh lunar craters which occur within a diameter range of 10 to 30 km In the present paper, seven ratio-level variations - those of rim-crest diameter with depth, rim height, flank width, rimwall slope, floor diameter, circularity, and rim-crest evenness - are defined for fresh-appearing craters from the new Apollo data and are expressed mathematically where practicable These relations constitute a shape model for interpreting fresh craters on the moon The size dependent changes reflect the occurrence of central peaks, rimwall terraces, and a flat floor within craters measuring 10 to 20 km in diameter

Size-dependence in the shape of fresh impact craters on the moon.

Topography of various types and scales can be fingerprinted by computer analysis of altitude matrices (digital elevation models, or DEMs). The critical analytic tool is the geometric signature, a set of measures that describes topographic form well enough to distinguish among geomorphically disparate landscapes. Different surficial processes create topography with diagnostic forms that are recognizable in the field. The geometric signature abstracts those forms from contour maps or their DEMs and expresses them numerically. This multivariate characterization enables once-in-tractable problems to be addressed. The measures that constitute a geometric signature express different but complementary attributes of topographic form. Most parameters used here are statistical estimates of central tendency and dispersion for five major categories of terrain geometry; altitude, altitude variance spectrum, slope between slope reversals, and slope and its curvature at fixed slope lengths. As an experimental application of geometric signatures, two mapped terrain types associated with different processes of shallow landsliding in Marin County, California, were distinguished consistently by a 17-variable description of topography from 21×21 DEMs (30-m grid spacing). The small matrix is a statistical window that can be used to scan large DEMs by computer, thus potentially automating the mapping of contrasting terrain types. The two types in Marin County host either (1) slow slides: earth flows and slump-earth flows, or (2) rapid flows: debris avalanches and debris flows. The signature approach should adapt to terrain taxonomy and mapping in other areas, where conditions differ from those in Central California.

Richard J. Pike

Papers

Elevation-Relief Ratio, Hypsometric Integral, and Geomorphic Area-Altitude Analysis

Slope failure and shoreline retreat during northern California's latest El Nino

Automated classifications of topography from DEMs by an unsupervised nested-means algorithm and a three-part geometric signature

Size-dependence in the shape of fresh impact craters on the moon.

The geometric signature: Quantifying landslide-terrain types from digital elevation models