Saturday, July 24, 2010

Distribution of population by ecological

Population ecology is a major sub-field of ecology that deals with the dynamics of species populations and how these populations interact with the environment.[1]
The first journal publication of the Society of Population Ecology, titled Population Ecology (originally called Researches on Population Ecology), was released in 1952.[1] Population ecology is concerned with the study of groups of organisms that live together in time and space. One of the first laws of population ecology is the Thomas Malthus' exponential law of population growth.[2] This law states that:
"...a population will grow (or decline) exponentially as long as the environment experienced by all individuals in the population remains constant."[2]:18
At its most elementary level, interspecific competition involves two species utilizing a similar resource. It rapidly gets more complicated, but stripping the phenomenon of all its complications, this is the basic principal: two consumers consuming the same resource.[3]:222
This premise in population ecology provides the basis for formulating predictive theories and tests that follow. Simplified population models usually start with four key variables including death, birth, immigration, and emigration. Mathematical models used to calculate changes in population demographics and evolution hold the assumption (or null hypothesis) of no external influence. Models can be more mathematically complex where "...several competing hypotheses are simultaneously confronted with the data."[4] For example, in a closed system where immigration and emigration does not take place, the per capita rates of change in a population can be described as:
dN / dT = B − D = bN − dN = (b − d)N = rN,
where N is the total number of individuals in the population, B is the number of births, D is the number of deaths, b and d are the per capita rates of birth and death respectively, and r is the per capita rate of population change. This formula can be read as the rate of change in the population (dN/dT) is equal to births minus deaths (B - D).[2][3]
Using these techniques, Malthus' population principal of growth was later transformed into a mathematical model known as the logistic equation:
dN / dT = aN(1 − N / K),
where N is the biomass density, a is the maximum per-capita rate of change, and K is the carrying capacity of the population. The formula can be read as follows, the rate of change in the population (dN/dT) is equal to growth (aN) that is limited by carrying capacity (1-N/K). From these basic mathematical principals the discipline of population ecology expands into a field of investigation that queries the demographics of real populations and tests these results against the statistical models. The field of population ecology often uses data on life history and matrix algebra to develop projection matrices on fecundity and survivorship. This information is used for managing wildlife stocks and setting harvest quotas [3][5]

The population distribution by village

At the time of the 1981 census, the total population of Nepal was 15,022,839, the average family was made up of 5.8 persons, and life expectancy at birth was close to fifty years. As of July 1990, the population was estimated at 19,145,800 persons. The annual population growth rate increased from less than 2 percent during the 1950s to more than 2.6 percent in 1990, suggesting that despite a trend toward increasing acceptance of family planning, the program did not have much influence on reducing the population growth rate. The Central Bureau of Statistics forecast that the total population would increase to 23.6 million by 2001 (see table 2, Appendix).
The 1981 census reveals a significant variation in regional growth rates. Although the Tarai Region's annual growth rate of 4.2 percent was much higher than the national average, the Hill and Mountain regions, respectively, posted growth rates of 1.7 and 1.4 percent. In terms of regional distribution, 43.6 percent (6,556,828 persons) of the country's population resided in the Tarai, whereas the shares of the Hill and Mountain regions totaled 7,163,115 (47.7 percent) and 1,302,896 (8.7 percent), respectively.
About 70 percent of the total population was of working age, or between the ages of fifteen and fifty-nine years. More than 65 percent of this segment of the population was considered economically active in 1981 (see Labor , ch. 3). In terms of employment structure, more than 91 percent of the economically active population was engaged in agriculture and allied activities, and the rest in the secondary (industrial) and tertiary (service) sectors, including government employment. In 1981 males and females who were widowed or separated constituted only a tiny fragment of the population--0.4 percent for each sex.

The population composition by age

Nepal is a country which is surrounded by countries from all the sides. The country of Nepal is situated in the continent of South Asia. Nepal is surrounded by the countries of India and China. Kathmandu is the capital of Nepal. Nepal Population in the year 2002 census was 23,151,423. In the year 2005 until the month of July, according to the estimate of the census, the Nepal Population was 27,676,547.The growth rate of the population of Nepal as in the year 2005 was recorded to be 2 percent. In Nepal 39 percent of the population are up to 14 years old. 57.3 percent of the total population of Nepal is between the age of 15 and 64. Only 3.7 percent of Nepal Population is aged above 65.The estimate of the population of Nepal according to the July 2007 census was 28,901,790. The total median age of Nepal is 20.5 years. The Male Median age in Nepal is 20.3 years and the Female Median Age is 20.6 years. According to the estimate given in the census of 2007 the population growth rate of Nepal is 2.132 percent.The birth rate in Nepal is recorded to be 30.46 births/1,000 populations according to the estimate of the year 2007. The death rate in Nepal is 9.14 deaths/1,000 populations according to the estimate of the year 2007.

The population composition by religion

Nepal was formerly the world's only constitutionally declared Hindu state, but following the movement for democracy in early 2006 and the breaking of King Gyanendra's power, the Nepali Parliament amended the constitution to make Nepal a secular state.
According to the 2001 census, 80.6 percent of Nepalese are Hindu, 10.7 percent are Buddhist, 4.4% are Muslim[1], 3.6 percent are Kirat (an indigenous religion with Hindu influence), 0.5 percent are Christian, and 0.4 percent are classified as other groups such as Bön religion. Although the population is mostly Hindu, since the 1971 census Hindus have shown the greatest decline as a proportion of the population, and Buddhists and Kirats have increased the most: in 1971 Hindus were 89.4 percent of the population, Buddhists 7.5 percent, and Kirats statistically 0 percent. However, statistics on religious groups are complicated by the ubiquity of dual faith practices, particularly among Hindus and Buddhists. Moreover, shifts in the population's religious composition also reflect political changes.
The geographical distribution of religious groups in the early 1990s revealed a preponderance of Hindus, accounting for at least 87 percent of the population in every region. The largest concentrations of Buddhists were found in the eastern hills, the Kathmandu Valley, and the central Tarai; in each area about 10 percent of the people were Buddhist. Buddhism was more common among the Newar and Tibeto-Nepalese groups. Among the Tibeto-Nepalese, those most influenced by Hinduism were the Magar, Sunwar, and Rai peoples. Hindu influence was less prominent among the Gurung, Limbu, Bhote, and Thakali groups, who continued to employ Buddhist monks for their religious ceremonies. Since both Hinduism as well as Buddhism are Dharmic religions, they usually accept each others practices and many people practice a combination of both.

The population composition by occupation

A census of agriculture may be defined as a government-sponsored operation for the collection of quantitative information on agricultural structure, including that on persons attached to agricultural holdings, covering in principle the whole of a country within a given agricultural year. The history of modern agricultural censuses is quite long in some countries, beginning in 1840 in the United States. In the 1920s some attempts had been made to set up a world-wide agricultural census based on harmonized definitions and classifications, with the intention that the 1930 round be the first of a series of such censuses taken at ten-years intervals. However, it was only after World War II that international standards became more widely used in national agricultural censuses. Since 1950, FAO has been assisting countries in planning and conducting censuses of agriculture. Each of the decennial World Census of Agriculture Programmes prepared by FAO provided methodological guidelines for organizing national agricultural censuses. The six decennial Programmes - centred on 1950, 1960, 1970, 1980, 1990 and 2000 - gradually expanded the census scope while keeping structural aspects of the agricultural production sector as the central theme.
Agricultural census results can be used in many different ways, ranging from very general to very specific technical applications. From a strictly statistical viewpoint, the census data represents one of the most important components of the information system in a country and can serve as the basis for many other statistical activities related to food and agriculture, such as conducting various agricultural sample surveys. While the raison d’être of the agricultural census is no doubt the use of census data for agricultural development planning and formulation of national agricultural policies, a much wider application of census results is possible.
This paper looks at agricultural censuses from the point of view of their applicability for the analysis of linkages between certain aspects of rural population change, natural resources and agricultural factors. Its objective is threefold: (a) to provide an overview of demographically relevant items available from censuses of agriculture, (b) to discuss selected subject areas that can be studied using population data from agricultural censuses, and (c) to identify some of the problems of using agricultural censuses to examine interactions between agricultural factors and demographic phenomena. Because the agricultural census is of particular importance to countries in which significant segments of the population depend on agriculture for their livelihood, the focus of the paper is on developing countries

The population composition by language

Nepalese are descendants of migrants from parts of earlier Greater Nepal, Tibet, India and parts of Burma and Yunnan along with native tribal population. Among the earliest inhabitants were the Kirat of east mid-region, Newar of the Kathmandu Valley and aboriginal Tharu in the malarial southern Terai region. The ancestors of the Khas (Bahun, Chhetri, Thakuri, Sanyasi, Dalit) migrated eastward along the himalayan foothills out of Kashmir, Kumaon, Garhwal-- parts of then Greater Nepal, Karnali Pradesh (Nepal) and perhaps also north from the Gangeatic Plains during invasions. Other ethnic groups trace their origins to North Burma, Yunnan and Tibet, e.g. the Gurung and Magar in the west, Rai and Limbu in the east, and Sherpa and Bhotia in the north.
In the Terai, a part of the Ganges Basin with 20% of the land, much of the population is physically and culturally similar to the Indo-Aryans of northern India. Indo-Aryan and East Asian looking mixed people live in the hill region. The mountainous region is sparsely populated above 3,000 meters, but in central and western Nepal ethnic Tibetans inhabit even higher semi-arid valleys north of the high Himalaya. Kathmandu Valley, in the middle hill region, constitutes a small fraction of the nation's area but is the most densely populated, with almost 5 percent of the nation's population. Nepal is a multilingual, multireligious and multiethnic society.

Male and female population of Nepal

Want to know more about the population in Nepal? The following figures (all approximate) should help to answer some of your questions. The figures are all taken from surveys carried out on the Nepalese population in 2006.
The population of Nepal was estimated at just over 28,000,000 in July 2006. When the population in Nepal was surveyed in 1981, the population was only 15,000,000. The increase in population has therefore been extremely rapid and the government in Nepal are seeking to slow down the rate through economic and social reforms.
58% of the population in Nepal fall primarily into the 15 – 64 year bracket, with 38% in the 0 – 14 year old bracket and only 4% in the 64 years or over category. The median age of the population in Nepal is 20 years and the life expectancy for the Nepalese population is 60 years for both genders. The latter statistic is a significant change from a survey carried out on the population of Nepal in 1981, which concluded that the average life expectancy in Nepal to be 50 years. It is also worth noting that men in Nepal are expected to live slightly longer than women (differing by a decimal point only). This population statistic is an anomaly and hence Nepal is an exceptional case. This situation may be due to a number of reasons, but likely factors include a traditional preference for male to female offspring in Nepalese society, nutritional deprivation and socio norms and values.
The Nepalese population is growing at a rate of 2.17%.
The population in Nepal is made up from diverse ethnic groups. The largest single ethnic group is Chhettri (16%), followed by: Brahman-Hill (13%), Magar (7), Tharu (7%), Tamang (6%), Newar (5%), Muslim (4%), Kami (4%), Yadav (4%) and ‘other’ (34%).
Since Nepal is the only official Hindu state in the world, the majority of the population in Nepal practice the Hindu religion (86% of the population), whilst the remaining religions are represented by Buddhists (8%), Muslims (4%) and ‘other’ (2%).
The population of Nepal is fairly poor with a GNP per head of household of $220. The population is also ageing and since the economic and social reforms referred to earlier in this document are effective then this has further heightened the increasing proportion of elderly people in the Nepalese population.