TIME AS AN INDEPENDENT VARIABLE FOR CURRENT RIPPLES DEVELOPING TOWARDS LINGUOID EQUILIBRIUM MORPHOLOGY

被引：18

作者：

BAAS, JH

OOST, AP

SZTANO, OK

DEBOER, PL

POSTMA, G

机构：

[1] Comparative Sedimentology Division, Institute of Earth Sciences, Utrecht, 3508 TA

[2] Department of Geology, L. Eötvös University, Budapest, H-1088

来源：

TERRA NOVA | 1993年 / 5卷 / 01期

关键词：

D O I：

10.1111/j.1365-3121.1993.tb00223.x

中图分类号：

P [天文学、地球科学];

学科分类号：

07 ;

摘要：

Flume experiments show that current ripples on very fine sand surfaces always develop towards a linguoid shape with constant height and wavelength provided that sufficient time is allowed for their formation. Straight and sinuous current ripples only reflect intermediate stages in ripple development and may be regarded as non-equilibrium bedforms. The time period which current ripples require to reach linguoid equilibrium morphology is related to an inverse power of flow velocity. In the transitional stage from current ripples to upper stage plane bed (i.e. washed-out ripple stage) only the equilibrium wavelength remains constant, whereas equilibrium height rapidly decreases to zero. Our observations imply that bed-roughness parameters in sediment transport calculations can be simplified when equilibrium conditions are attained, and that inferences about flow energy from the dimensions of current ripples in very fine sand need to be regarded with caution.

引用

页码：29 / 35

页数：7

共 18 条

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