| 释义 |
zero population growth
zero population growthn. The lack of an increase in the number of individuals in a given population, occurring when the birth rate equals the death rate.ze′ro popula′tion growth`
n. a condition in which the population is maintained at a constant level by a balance between the number of births and deaths. [1965–70] Translationszero population growth
zero population growth[′zir·ō ′päp·yə‚lā·shən ‚grōth] (ecology) A theory which advocates that there be no increase in population, that each person replace only oneself, and that birth control be practiced in all nations. zero population growth
The birth rate at which there is no net increase in population—a goal of some birth control programs—and the number of births equals the number of deathszero population growth, ZPGThe demographic equilibrium in which in a given period of time the population neither increases nor decreases, that is, the death and birth rates are equal.zero population growth (ZPG) a state in a population in which births equal deaths, so that overall numbers remain in a steady state. ZPG (or even negative growth) has been achieved in many Western countries where the family size is low but has, so far, proved an impossible target for most Third World countries, the state being achieved only where there is widespread use of contraceptives (see BIRTH CONTROL, DEMOGRAPHIC TRANSITION)Zero Population Growth
Zero Population GrowthA situation in which the number of persons born in a population equals the number of persons who die. The fertility rate necessary for zero population growth varies, but is generally between 2 and 3. Some countries concerned about overpopulation aim for zero-population growth, while others dealing with an aging population may wish to increase the growth rate.AcronymsSeeZPG |