Arithmetic Population Density
Arithmetic population density is a measure of population distribution calculated by dividing the total population of an area by its total land area. It provides a simple way to compare population densities between different regions. This measure is often used in geography to understand the concentration of people in a given area.
4 Key excerpts on "Arithmetic Population Density"
eBook - ePubPopulation Geography
A Systematic Exposition
- Mohammad Izhar Hassan(Author)
- 2020(Publication Date)
- Routledge India(Publisher)
...In the case of Egypt, while the crude density is only 93, physiological density works out to be nearly 3,498 thousand persons per square kilometres of arable land according to PRB, 2017. This measure is very appropriate for a situation where agriculture is the mainstay of population. But it is also true that not all the people in a region or country are dependent on agriculture. Thus, physiological density also does not provide an accurate picture of population pressure on land. As a further refinement, agricultural density is worked out which refers to a ratio between the number of people earning their living or subsistence from working the land and the total amount of farmland. In the economically advanced countries, agricultural densities are very low as compared to the less advanced countries. As cultivable and cultivated areas of a region or country are generally not of uniform value, agricultural density does not provide an exact account of man-land relations. Vincent, a French geographer, in 1946, therefore, suggested an index, which he termed as comparative density (Clarke, 1972:30). In the calculation of comparative density, total population of a region is related to the aggregate of weighted land under cultivation according to its productivity. Thus, it is type of physiological density taking into account the varying levels of productivity of cultivated lands in any area. It is worthwhile to note here that the measures of density discussed earlier are of no practical value for areas which are more urbanised and industrialised. In the developed countries of the West vertical expansions of residential complexes invalidate the relationship between population and areas, and these measures, therefore, reveal nothing about the concentration of people within buildings...
eBook - ePubAn Introduction to Population Geographies
Lives Across Space
- Holly R. Barcus, Keith Halfacree(Authors)
- 2017(Publication Date)
- Routledge(Publisher)
...These include proximity to resources, historical distribution of lands and land tenure issues, transportation systems, distribution of amenities and individual preferences. They are inextricably entangled with the arenas of life course construction outlined in Section 2.3. In South America, for example, the population is not evenly distributed but clustered along the coastlines and a few interior cities, leaving large areas of low population density. Knowing the extensiveness of the Amazon rainforest and the difficulty of living in the Andes mountains, for example, gives immediate physical geographic clues to these spatial patterns, even if these factors alone are unable to explain the full picture. Figure 3.2 World population distribution 2015. Data Source: Center for International Earth Science Information Network (CIESIN), Columbia University; United Nations Food and Agriculture Programme (FAO); Centro Internacional de Agricultura Tropical (CIAT) 2005; SEDAC. Fortunately, Geographers’ methods to measure population density and distribution have evolved as rapidly as the populations being measured. Censuses (Box 3.2), population registers and surveys that count the number of people who reside in a particular area help production of density measures. Advanced technologies, such as satellite images and aerial photography, can further be employed for population estimation. For example, Rindfuss et al. (2002) utilized Geographic Information Systems and remote sensing to link data about changes in village practices and landscape change in Nang Rong, Thailand. Similarly, Fox (2002) utilized aerial photography and socioeconomic data to assess the multiple dimensions of land change, including the implications of land tenure policies, on land use practices in several villages in northeastern Cambodia...
eBook - ePubDemographics
A Guide to Methods and Data Sources for Media, Business, and Government
- Steven H. Murdock, Chris Kelley, Jeffrey L. Jordan, Beverly Pecotte, Alvin Luedke(Authors)
- 2015(Publication Date)
- Routledge(Publisher)
...In international statistics, density is usually computed as persons per square kilometer or hectare. In still other cases, demographers are interested in how different types of people are distributed across the same space. For example, the segregation of racial/ethnic groups is often examined in terms of residential segregation, and such segregation is usually measured by statistical measures that examine the similarity in the relative percentage of two populations living in a given set of geographic units (such as census tracts or blocks). For example, if the residential patterns of Blacks and Whites are being compared across a common level of geography (such as tracts) and 90 percent of Blacks live in one subset of tracts in a city while 90 percent of Whites live in another largely nonoverlapping subset of tracts, these two populations are said to be highly segregated. Measures such as the Index Of Dissimilarity and the Gini Coefficient (described in the next chapter) generally have values between 0 and 1, with values closer to 1.0 indicating higher levels of maldistribution (i.e., segregation) between the populations. The composition of a population describes its characteristics. The most commonly described characteristic in demographic analyses are those shown in Figure 1.1. Below we briefly define each of these and discuss some common uses of them. Age is among the most important demographic and social factors. Age determines everything from legal rights (e.g., you must be 18 years of age or older to vote in the United States), to the likelihood of experiencing certain events (e.g., the probability of dying increases with age), to the social expectations that are placed on members of a population. For example, a person in the United States is expected to marry in his or her late teens or 20s and to raise children as a young and middle aged adult. Age also tends to be closely associated with other characteristics...
eBook - ePubApplied Population and Community Ecology
The Case of Feral Pigs in Australia
- Jim Hone(Author)
- 2012(Publication Date)
- Wiley-Blackwell(Publisher)
...Individuals are often clumped (or ‘aggregated’) (Taylor 1961) in many animal and plant populations (Anderson et al. 1982). Rarely are individuals randomly or regularly dispersed within a population (Taylor 1961). Population Density Population density is defined as the number of individuals per unit area. Density can be estimated using a range of methods (Seber 1982; Krebs 1999; Lancia et al. 2005), usually involving counting individuals or groups, mark-recapture, or counting signs such as dung. The evaluation of indices has been encouraged (Engeman 2003, 2005) and debated (Anderson 2003). In this study, indices are evaluated, as described in Chapter 4. A variety of density-estimation methods have been used in the Australian high country for feral pigs and birds. These include mark-recapture analysis (McIlroy et al. 1989; Pech & McIlroy 1990), dung counts (Hone 1988a) and area counts (Osborne & Green 1992; Hone 1995). These are described in more detail in Chapters 4–7. Dynamics Trends in wildlife density are of great interest, as they can be used to assess whether a population is increasing, decreasing or stable over time. Table 2.1 lists many measures of trend in use. The most common measures are percentage change, the finite population growth rate (λ) and the instantaneous population growth rate (r) (Table 2.1). Rates are commonly measured over 1 year. The percentage change is used in assessments of conservation status, such as those listed by IUCN: namely threatened, vulnerable and endangered (www.redlist.org). A short example illustrates the differing measures: A population that doubles from 1000 to 2000 over 1 year shows a 100% increase per year, an annual finite population growth rate (λ) of 2.0 and an annual instantaneous population growth rate (r) of 0.692. A population that halves over 1 year from 1000 to 500 shows a decrease of 50%, an annual finite rate of 0.5 and an annual instantaneous rate of −0.692...
