整个流域的人口分布沿黄河河道由下游往上，人口密集程度呈梯度递减的特征。

There were grades in the population intension level from the lower reaches of the river to the upper river.

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整个流域的人口分布沿黄河河道由下游往上，人口密集程度呈梯度递减的特征。

There were grades in the population intension level from the lower reaches of the river to the upper river.

youdao