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Earth and Space Sciences · 术语表

什么是 Delta?

Definition 10.9 Primary & Middle School Earth and Space Sciences · 第 10 章 — Water Shapes the Land

A delta is new, flat land built by a river at its mouth from the mud and sand it lays down. The river splits into several branches that spread across it, often in the shape of a fan.

Left: a delta seen from above; the mud and sand laid down by the branches build new land beyond the old coast. Right: the Nile delta, in Egypt, from a satellite (sea at the top): a green fan of fields on the river’s mud, in the middle of the desert. Photograph: NASA (public domain).
Left: a delta seen from above; the mud and sand laid down by the branches build new land beyond the old coast. Right: the Nile delta, in Egypt, from a satellite (sea at the top): a green fan of fields on the river’s mud, in the middle of the desert. Photograph: NASA (public domain).
Left: a delta seen from above; the mud and sand laid down by the branches build new land beyond the old coast. Right: the Nile delta, in Egypt, from a satellite (sea at the top): a green fan of fields on the river’s mud, in the middle of the desert. Photograph: NASA (public domain).
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