zero balanced

As the zero-balanced surface of rainfall, the snowline can be defined as the lower limit of the perennially snow-covered area, and it is a geographic element as important as the tree line, the periglacial line and the soil line.

雪线是降水的零平衡面，作为终年积雪区的下界，是与林线、冰缘线和土壤线等界线同等重要的自然地理区划线。

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