人 文 地 理(3轮)3.ppt

人 文 地 理 HUMAN GEOGRAPHY 第三章 人口分布与迁移Population Distribution and Migration Population geography provides the background tools and understandings of those interests. It focuses on the number,composition, and distribution of human beings in relation to variations in the conditions of earth space. It differs from demography. Demography, the statistical study of human population, in its concern with spatial analysis—the relationship of numbers to area. 第三章 人口分布与迁移Population Distribution and Migration 第一节 人口分布 一 人口密度 （Population Density ） 二 世界人口分布特征及一般规律 (World Population Distribution) 第三章 人口分布与迁移Population Distribution and Migration Margins of habitation could only be extended，of course，as humans learned to support themselves from the resources of new settlement areas. The numbers that could be sustained in old or new habitation zones were and are related to the resource potential of those areas and the cultural levels and technologies possessed by the occupying populations. We express the relationship between number of inhabitants and the area they occupy as population density. 第三章 人口分布与迁移Population Distribution and Migration Density figures are useful,if sometimes misleading, representations of regional variations of human distribution. The crude density or arithmetic density of population is the most common and least satisfying expression of that variation. It is the calculation of the number of people per unit area of land , usually within the boundaries of a political entity. It is an easily reckoned figure. 第三章 人口分布与迁移Population Distribution and Migration It can, however, be misleading and may obscure more of reality than it reveals. It is an average,and a country may contain extensive regions that are only sparsely populated or largely undevelopable along with intensively settled and developed districts. A national average density figure reveals nothing about either class of territory.in general, the larger the political unit for whi