THE DISTRIBUTION OF THE SIZE OF FLUVIAL GRAVELS
| Autor: | Masatami Nakayama |
|---|---|
| Rok vydání: | 1952 |
| Předmět: | |
| Zdroj: | Geographical Review of Japan. 25:401-408 |
| ISSN: | 2185-1719 0016-7444 |
| Popis: | The writer investigated the distribution of the size of fluvial gravels along six streams in Kwanto, and Hokuriku Districts. In this paper, each gravel size represents the arithmetic mean value of 30 pieces of gravels that are large in size. The conclusions of this paper are as follows: 1). According to Sternberg's law, the size of fluvial gravels decreases with the distance of transport and in some streams it decreases exponentially as a function of distance. In a few streams, however, actually it does not follow this exponential law and the size decreases abruptly. 2). The distribution of the size of fluvial gravels is related to the gradient of the river floor. Therefore, selective transportation is the main factor and abrasion is secondary. 3). The correlation between the ratio of decrease in size and the meane volulae of discharge has been shown in figure 4, but this correlation is not so clearly seen. A stream gradient, therefore, must be the most important factor among those concerned with selective transportation. 4). The more increase is seen in the gradient of a river floor, the larger is the ratio of decreasing size co-efficient to decreasing height co-efficient. But this relation does not exist in such a river as having a very abrupt: gradient. |
| Databáze: | OpenAIRE |
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