Spectral analysis of seabed elevation from the Danish Wadden Sea

Bedforms both reflect and influence shallow water hydrodynamics and sediment dynamics. A correct characterization of their spatial distribution and dimensions is required for the understanding, assessment and prediction of numerous coastal processes. A method to parameterize geometrical characteristics using two-dimensional (2D) spectral analysis is presented and tested on seabed elevation data from the Knudedyb tidal inlet in the Danish Wadden Sea, where large compound bedforms are found. The bathymetric data were divided into 20x20 m areas on which a 2D spectral analysis was applied. The most energetic peak of the 2D spectrum was found and its energy, frequency and direction were calculated. A power-law was fitted to the average of slices taken through the 2D spectrum; its slope and y-intercept were calculated. Using these results the test area was morphologically classified into 4 distinct morphological regions. The most energetic peak and the slope and intercept of the power-law showed high values above the crest of the primary bedforms and scour holes, low values in areas without bedforms, and intermediate values in areas with secondary bedforms. The secondary bedform dimensions and orientations were calculated. An area of 700x700 m was used to determine the characteristics of the primary bedforms. However, they were less distinctively characterized compared to the secondary bedforms due to relatively large variations in their orientations and wavelengths. The method is thus appropriate for morphological classification of the seabed and for bedform characterization, being most efficient in areas characterized by bedforms with regular dimensions and directions.

The effort of the Danish kings to recover the English crown after the death of Harthacnut,

Mode of access: Internet.

The gentleman and lady's key to polite literature, or, A compendious dictionary of fabulous history : containing the characters, and principal actions, ascribed to the heathen gods, goddesses, heroes, &c. and the manner in which the ancients represented the deities & heroes ... : intended for the assistance of those who would understand mythology, poetry, painting, statuary and theatrical entertainments, and particularly adapted to the use of Latin and French schools.

Frontispiece signed "Le Pautre." Engraved title-page.

The micrographic dictionary : a guide to the examination and investigation of the structure and nature of microscopic objects /

vols 1 and 2.

Ayer's American almanac : for the use of farmers, planters, mechanics, and all families ...

Issue for 1889 includes French, Spanish, Portuguese, Finnish, German, Dutch, Swedish, Norwegian-Danish, Bohemian, Welsh, and Italian sections.

A Mandarin-Romanized dictionary of Chinese, with supplement of new terms and phrases, now current,

Chinese title at head of t.-p.

Sylvelin : op. 55, [Nr.] 1 [for voice and piano] /

Text in Danish, German and English.

Adjudged words and phrases : being a collection of adjudicated definitions of terms used in the law, with references to authorities /

Mode of access: Internet.

Guide to motor vehicle titling and registration terminology. Final report.

National Highway Traffic Safety Administration, Washington, D.C.

A brief narrative of the Danish mission on the Coast of Coromandel.

Mode of access: Internet.

Glossary of library terms, English, Danish, Dutch, French, German, Italian, Spanish, Swedish,

Mode of access: Internet.

Supplement to the American and English encyclopaedia of law (2d ed.)

Mode of access: Internet.

A dictionary of photography : for the amateur and professional photographer /

Advertisements printed on endpapers, and on p. i-ix and p. 242-261.

Glossary of terms and table of conversion factors used in design of chemical propulsion systems.

Cover title.

A glossary of terms used in Grecian, Roman, Italian, and Gothic architecture.

Includes bibliographical references and index.