Statistical texture for contour interval choice of 1:50,000 DEMs

2009 ◽  
Author(s):  
MingLiang Luo ◽  
Guoan Tang ◽  
Shijiang Yan ◽  
Youfu Dong
Keyword(s):  
Contour Interval

SOME FUNDAMENTAL CONSIDERATIONS ON GLACIER MAPPING

1966 ◽  
Vol 3 (6) ◽  
pp. 747-759 ◽  
Author(s):  
T. J. Blachut ◽  
F. Müller
Keyword(s):  
Catchment Area ◽  
Research Council ◽  
Canadian Arctic ◽  
National Research Council ◽  
Mass Change ◽  
Contour Interval ◽  
Research Section ◽  
Mcgill University ◽  
Mapping Scale ◽  
Glacier Mapping

Five glacier maps at scales of 1:5 000 and 1:10 000 were produced by the Photogrammetric Research Section of the National Research Council and the Axel Heiberg Island Expedition of McGill University for use in glaciological research in the Canadian Arctic. After general comments on the need for and scope of glacier mapping, the authors discuss in some detail the main problems encountered. It is maintained that glacier maps belong to the class of 'special maps' and that the specifications for them should be set by the glaciologists.Accuracy requirements, choice of mapping scale and contour interval, delineation of various glacier units, extent of detail plotting, etc. are critically reviewed, The 1:10 000 map of the entire White Glacier catchment area, accompanying this paper, is an example of a map which serves various glaciological purposes, primarily calculations of mass change. To facilitate future glacier mapping, the authors suggest that clear definitions of glaciological terms such as 'active glacier' or 'glacierized area' should be established and that their cartographical presentation should he further standardized.

The Calculation of Volumes of Middens, Mounds, and Strata Having Irregular Shapes

1984 ◽  
Vol 49 (3) ◽  
pp. 599-603 ◽  
Author(s):  
Peter E. Sorant ◽  
J. Richard Shenkel
Keyword(s):  
Precise Determination ◽  
Critical Aspect ◽  
Contour Map ◽  
Contour Mapping ◽  
Contour Interval ◽  
Irregular Shapes ◽  
Mound Construction ◽  
Human Effort ◽  
Mapping Program

A critical aspect in the estimation of human effort embodied in mound construction or in midden deposition is the volume of the deposit. When these deposits are of irregular contour, the use of standard geometric formulae for the determination of volumes of solids is inadequate. Given a basic contour map of a given deposit, a rather precise determination of volume can be calculated by the application of the formula derived from that for the volume of a truncated cone. The use of the formula involves the determination of the volumes between contour intervals, and then adding the successive contour interval volumes. This is done by measuring the areas of adjacent contours and inserting those data into the formula. The procedure can be accomplished by hand, using grid paper or a compensating polar plenimeter, or by computer–either mainframe or micro–by the incorporation of the formula into an existing contour mapping program.

Fish Habitat: Essential Fish Habitat and Rehabilitation

1999 ◽  
Keyword(s):  
Rhode Island ◽  
Statistical Tests ◽  
Fish Habitat ◽  
Sampling Technique ◽  
Homarus Americanus ◽  
Sidescan Sonar ◽  
Density Estimates ◽  
Side Scan Sonar ◽  
Contour Interval ◽  
Definition Of

<em>Abstract.</em> —The American lobster <em>Homarus americanus </em> is usually associated with rocky substrate that provides or can be modified into shelter and that may be an essential habitat to early benthic-phase juveniles. The dependence on shelter-providing habitat not only makes possible the definition of essential habitat for lobsters but also permits the assessment of abundance based on the areal extent of habitat. Here, we describe such a habitat-based assessment, performed in response to an oil spill on the coast of Rhode Island, USA. Results from a side-scan sonar survey performed after the spill indicated that the amount of lobster habitat affected by the oil was approximately 9.8 km2 along nearly 15 km of coastline. Postspill lobster density ranged from 0.24 lobsters m22 in the impact region to 1.63 lobsters m22 in the control region. Qualitative (map contours of lobster density) and quantitative (statistical tests) approaches suggested a significant effect of the spill had been detected by our sampling. An estimate of the total number of lobsters killed was required to scale restoration efforts. We calculated the total number of lobsters in the area by overlaying contours of lobster density on a habitat map generated by side-scan sonar, then multiplying the density of lobsters in each contour interval by the area of appropriate lobster habitat (cobble and boulder) in the contour interval. To calculate loss, we subtracted postspill abundance from prespill abundance. Prespill density was estimated to be 1.76 m22, which is an adjusted average of airlift samples taken at six Rhode Island sites four months prior to the spill. Calculations of loss based on habitat-specific density estimates were adjusted to reflect undersampling. The loss was estimated to be to be 9.0 × 106 lobsters. Variability associated with this loss estimate is large; 95% confidence intervals estimated that between 6.7 × 106 and 15.6 × 106 lobsters were lost. The calculated loss was very sensitive to changes in prespill density estimates; a change of 0.1 lobsters m22 resulted in a change of 0.75–0.9 × 106 lobsters lost. Habitatbased assessment of lobster population size is possible but requires detailed habitat maps and accurate density estimates. Natural variability and sampling limitations give such assessment a wide range of possible values. Nevertheless, the airlift sampling technique, together with sidescan sonar maps of habitat, could provide a powerful tool for estimating the abundance of inshore lobsters.

Similarities among Transformed Melodies: The Abstraction of Invariants

1986 ◽  
Vol 3 (4) ◽  
pp. 393-409 ◽  
Author(s):  
Edward C. Carterette ◽  
Donald V. Kohl ◽  
Mark A. Pitt
Keyword(s):  
Acquisition Phase ◽  
Alternative Measure ◽  
Contour Interval ◽  
Musical Transformation

In studying the abstraction of musical ideas from diverse invariants, six-note melodies of varying note durations and note intensities were used as prototypes. Four types of transformations on a prototype distorted each of four musical components: contour, interval, loudness, and duration. In an acquisition phase, listeners heard simple transformations on a single prototype, but in recognition heard both simple and compound transformations as well as the prototype, which had been unheard in acquisition. Predictions were borne out, namely, that both prototypes and simple transformations were falsely recognized with greater certainty than any other transformed melodies; and latencies of recognition of the prototypes, an alternative measure of certainty, were shorter than latencies of recognition of any other transformed melodies. It is argued that the methods used enable the examination of the properties of musical transformation spaces.

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