A first order stream may be very small, seasonal or ephemeral and not have a formal name.

一阶流可能非常小、季节性 或短暂且没有正式名称。

Then when two first order streams join, they create a second order stream. And on and on.

然后，当两个一阶流加入时，它们会 创建一个二阶流。 不断地。