The region has a very high population density.

这一地区人口密度很高。

《柯林斯英汉双解大词典》

The population density of that country is 685 per square mile.

那个国家的人口密度为每平方英里685人。

《新英汉大辞典》

The average population density of the world is 47 persons per square mile.

世界平均人口密度为每平方英里47人。

youdao

We have low population density, clean air, fresh water, fertile land, an ocean on either side and a grand total of two nations on our borders. (One of which is a also a huge, stable and peaceful nation with clean air, fresh water, and fertile land and even lower population density).

FORBES: Crossroads for the Sole Superpower

Its deadliness was linked, among other things, to the weakness of buildings, the depth of the quake, the density of population, the fault and soil types, and the intensity of the shaking.

ECONOMIST: Why the Kashmir earthquake happened and what might be done

There are also huge differences in population density across the country, with the population per square kilometre ranging from nine in Eilean Siar (the Western Isles) and the Highlands to 3, 395 in Glasgow.

BBC: Census shows 'highest' Scottish population ever