Issues of determining the effects of migration on population growth in Ulaanbaatar

: Since Mongolia's transition to a market economy in the 1990s, the “Great Migration” from rural to urban areas due to job shortages and natural disasters (droughts and dzud - disaster affecting livestock caused by severe natural conditions) in rural areas has continued. Many of these in-migrants have settled in large cities and their suburbs, especially in Ulaanbaatar, leading to many problems, including environmental pollution, traffic congestion, and overcrowding of social services. In addition, a number of studies have been conducted in Mongolia about the types of internal migration, factors influencing it, causes, characteristics of migrants, consequences and vulnerabilities. However, there is a lack of research about population location, density, settlement and their changes due to migration, especially the urban-rural population ratio, urban population growth and the impact of migration on it. Therefore, the main purpose of this study is to analyze the main indicators of population migration in Ulaanbaatar, to determine its impact on population growth, to evaluate and to determine future trend. Within the framework of the study, spatial and statistical analysis of data and materials of the last 30 years (1990-2019) of the main population indicators of Ulaanbaatar was conducted and future trend was determined based on the population projections. According to the research results, in-migrants were always dominant in Ulaanbaatar from 1990 to 2019, and the intensity of migration generally increased in the years following droughts and dzuds. In addition, a total of 663.1 thousand people migrated to Ulaanbaatar from aimags and rural areas over the last 30 years, which is equal to 45.2 percent of the total population of Ulaanbaatar in 2019. As a result, urban population of Mongolia counted 2,212.9 thousand in 2020, and the urbanization rate reached 68.0 percent, of which 67.7 percent is concentrated in Ulaanbaatar alone. Between 2000 and 2009, 47.4 percent of the total in-migrants (1990-2019) or 314.5 thousand people moved to Ulaanbaatar, which was the peak of migration to Ulaanbaatar. From a population perspective, Ulaanbaatar's population is expected to reach 2.5 million or the equivalent of 50.5 percent of the total population of the country in 2050. In order to reduce overcrowding in Ulaanbaatar, it is necessary, in the future, to reduce inland migration from rual areas to Ulaanbaatar, reduce the gap between urban and rural development levels, support and develop regional development cities, and diversify settlements system.


INTRODUCTION
Population migration is one of the most important issues of population geography, which has both positive and negative impacts on all aspects of the country's society, economy, population growth, jobs, comfortable living environment, culture, education and health service quality and access, citizens' standard of living, social welfare, protection, and urban planning [1].The government of Mongolia develops and implements social and economic policies and programs in order to respect the right to move freely anywhere in the vast territory of the country, to create conditions for choosing a place to live and work, and to gradually eliminate the differences in the level of urban and rural development.Migration from rural to urban areas is not decreasing due to the lop-sided development of infrastructure, information, communication, comfortable working environment, as well as a quest for a better place to get quality education and health care [2].According to the 1990-2019 statistics, a total of 663.1 thousand people migrated to Ulaanbaatar from rural areas, while 179.2 thousand people out migrated to rural areas.The net migration was 483.9 thousand people, which is equal to 45.2 percent of the total population of Ulaanbaatar in 2019 [3].
After Mongolia transitioned to market economy in the 1990s, there has been a continued "Great Migration" from rural to urban areas, particularly of livestock breeders who have lost their livestock due primarily to natural disasters (drought, and drud) [4] depriving of their livewlihood mainstay, and also because they could not find appropriate jobs in the rural areas.These in-migrants settled in the central part of our country, in large cities and their suburban areas.This has had a real impact on many social and economic factors, such as the loss of population distribution and proper settlement system, increasing the burden of urban areas, creating excessive population concentration, increasing environmental pollution, and differences in regional economic development [5].As a result, as of 2020, Mongolia's urban population reached 2212.9 thousand, and the level of urbanization was 68.0 percent, which is an increase of 1037.5 thousand people or 88.2 percent, and the level of urbanization has increased by 13.5 points, respectively, compared to 1990 [6].This trend was calculated based on the prospective estimation of Mongolia's population projection until 2045 released by the NSO in 2015.The total population of Mongolia will be 5,010.4thousand, of which the population of Ulaanbaatar will be 2,868.7 thousand or 57.2 percent of the total population of the country in 2045, which is expected to increase rapidly [7].
Due to the internal migration of the population, there are significant changes in the location, density, and settlement of the country's population [8], and researchers in this field in our country have been studying the types of migration, the factors affecting inland migration, their causes, characteristics, consequences, and the vulnerability encountered by the migrants [3].However, there has been almost no research into the changes in the location, density, and settlement of the population due to internal migration, especially the ratio of the urban and rural population, the growth of the urban population, and the impact of migration on it.In addition, internal migration of population is one of the main factors affecting the formation of a proper system of population distribution and settlement.It is necessary to study the growth, trends, and the impact of migration on the population of Ulaanbaatar, based on scientific research, at a time when the Government of Mongolia is developing the Regional Development Policy and the General Plan for the Development of Population Distribution and Settlement.Therefore, the main goal of this research work is to

PMAS
Proceedings of the Mongolian Academy of Sciences determine population migration of Ulaanbaatar and its impact on population growth, and the following objectives are proposed, including: 1.To determine the characteristics of population migration in Ulaanbaatar 2. To detect the effect of migration on population growth in Ulaanbaatar.

Literature review
Scholars and researchers of the Department of Social and Economic Geography of the Institute of Geography (former name) of the Mongolian Academy of Sciences have played an important role in reviewing the studies conducted in the field of internal migration of the population of Mongolia.For example, Academician B. Gungaadash (1963Gungaadash ( , 1986) ) analyzed the changes in the number, age structure, and settlement of the country's population and concluded that the net growth of the population not only directly affects the distribution and changes of labor resources, but also the migration of the population is important.Professor M. Bayantor (1971,1995) considered population migration in connection with the development of urban areas and concluded that the intensity of population migration and the settlement of migrants have a significant impact on the development of urban areas.He suggested that the result of migration is represented by settlement and location of the population.Geographer O. Sukhbaatar (1973) made the first attempt to systematically study the population migration of Mongolia and wrote a book called "Population migration of the Mongolian People's Republic ".Dr. J. Oyungerel (2005) studied in detail the "geographic issues of population migration in Mongolia in the new social and economic conditions" and classified the factors affecting migration into social, economic and ecological, and determined the territorial differences in migration.regions and Ulaanbaatar city according to the criteria of in-migrants and out-migrants after birth over a period of the last 5 years and 1 year, and migration participants were disintegrated by age, gender and education.It also analyzed the reasons for migration, the problems faced by migrants, changes after migration, the policies and programs of the government regarding future migration.
If we look at the studies conducted in the field of internal migration of population in Mongolia, we find that there are many studies that analyze the types of migration, factors, characteristics, vulnerabilities, and problems of migrants, but there are almost no studies detailing the location and settlement of the population, especially the effects of migration on the growth of the population of Ulaanbaatar.However, this matter was analyzed by M. Altanbagana et al. (2022) within the framework of a project called "Redevelop the basis of the theory, integrated methodology, and method of regional development in Mongolia " and S.

PMAS
Proceedings of the Mongolian Academy of Sciences Narantulga (2018) had taken up this matter in her work on migration in the Mongolian society.Population migration is a socioeconomic geographic process with spatial and temporal dimensions, which depends on many social, economic, and natural factors and resources.In order to detect the territorial disparities of migration, the basic indicators of in-and out-migrants, and the intensity of migration are used [8].The amount of population migration or the number of migrants is an indicator of the total sum of the number of in-and outmigrants in a given country or a region for a certain partial period (year, month).But the intensity of migration is the ratio of the total number of people who have left and arrived within a certain period of time per 1,000 or 10,000 people in that country or region.Migration gap or net migration refers to the difference between the number of people who have moved and migrated to a country or state in a certain period of time, and if the number of migrants exceeds the number of emigrants, it is net migration, and otherwise, it is net migration [18].The main indicators of population migration are compared to 1,000 people to eliminate the population's effects.However, the ratio of the difference between the number of people who have migrated and those who have migrated to the average annual population is called the net migration coefficient.It is calculated using the following formulas [19].On the one hand, the phenomenon of population change depends on the net growth of the population or the normal growth of the population, and on the other hand, on the mechanical growth of the population (migration).Normal growth is calculated by subtracting the number of deaths from the number of children born in a given year and depending on the number of births and deaths, this indicator can be either positive or negative.

Key
But mechanical growth or net migration refers to the difference between inmigrants and out-migrants to a country or region in a certain period of time, and if the number of in-migrants exceeds the number of out-migrants, then it is called net migration [18].The method of calculating population changes using these indicators is called the component method and is calculated using the demographic balance formula.

In -Total in-migrants Out -Total out-migrants
The population calculated by the population balance formula sometimes differs from the year-end population declared by official statistics.This is due to differences in one or more of the birth, death, or migration indicators used in the component calculation, or in the census population.In other words, in practice, the information is incomplete or incorrectly recorded, and this type of error is common in countries with poorly developed civil registration and information systems.In such a case, the demographic balance formula is computed as follows.

𝑃𝑡 -𝑃𝑜 = (𝐵 − 𝐷) + (𝐼𝑛 − 𝑂𝑢𝑡) + 𝑒 (5) e-is closure error, or the difference in estimates due to demographic phenomena or missing/incorrect registration of population numbers
Population change data calculated using the component method can be used to determine the percentage, level, and component contribution of population growth.In doing so, the parameters of the population balance formula will be compared to the average annual population and will be calculated using the following formula [19].
The ratio of mechanical growth to net growth is one indicator of how migration has affected population growth, which is calculated using the following formula.

Ratio of MG to NG -is the ratio of mechanical growth to net growth
If the ratio of MG to NG is >0, this means that migration has had a positive effect on population growth or the population has increased due to migration, and if the ratio of MG to NG is >100, this means that net migration has had a greater impact on population growth than normal growth, respectively [20].

RESULTS AND DISCUSSION
The new Constitution of Mongolia has given the citizens the right to freely choose their place of residence.It put an end to previous society's administrative regulation of migration of citizens, as a result of which population migration intensified in the 1990s.In 1991-1992, the privatization of collective and fund enterprises took place in rural areas, and people interested in taking part in the privatization process migrated from cities to rural areas [8].Considering the intensity of population migration in Ulaanbaatar from 1990 to 2019, it was stable from 1990 to 2002, from 13.5 to 29.1, to 46.Our estimated results, effects of migration on population growth in Ulaanbaatar on the last three decades are 40-50%, which is different by nearly 70% of recent population growth owing to migration, estimated by Yecheng Xu et al (2021) [21].It is believed that the reason lies in the fact that our calculations are based only on statistical data.
If this trend continues, by 2045, the total population of Mongolia will reach 5010.4 thousand, of which the population of Ulaanbaatar will be 2868.7 thousand or 57.2 percent of the total population of the country, and it will increase rapidly.In order to reduce overcrowding in Ulaanbaatar in the future, it is important to curtail migration to Ulaanbaatar from rural areas, reduce the gap between urban and rural development level, support and develop regional development cities, and establish diversified settlements system.

CONCLUSIONS
By carrying out this research work, we have achieved a set of goals and objectives, basing on which we can draw the following conclusions: -Considering the main indicators of population migration in Ulaanbaatar in the last 30 years, the number of participants in total migration and the intensity of migration were relatively stable in the first ten years, which then increased sharply in the mid decade and reached their peak values, but in the last ten years there has been a steady decline.In total, 663.1 thousand people migrated to Ulaanbaatar city from rural aimags and villages from 1990-2019, 179.2 thousand people left, and net migration was 483.9 thousand people.
-The highest number of migrants was in the years immediately after droughts and dzud, i.e. in 2003-2004 and 2010, and considering the number of migrants by aimag, more than 40,000 people migrated from Central, Darkhan-Uul, Zavkhan and Selenge aimags respectively.Although the number of migrants has been increasing since 2005, migration has always dominated over the past 30 years.Considering the number of migrants by aimag, more than 10,000 people migrated to such rural provincesas Central, Darkhan-Uul, Orkhon, Selenge, Dornogovi, and Khentii.
-From 1990 to 2019, the population of Ulaanbaatar increased by 929.5 thousand, but according to the component method, normal growt is 483.9 thousand and mechanical growth is 469.8 thousand.24.2 thousand people are related to errors in the civil registration system.The share of mechanical growth in population growth is 50.7.When comparing the share of mechanical growth in population growth by three decades, it is 50.8 percent in 1990-1999, 70.0 percent in 2000-2009, and 32.7 percent in 2010-2019.In addition, 47.4 percent of those who migrated in the last 30 years or 314.5 thousand people migrated to Ulaanbaatar in 2000-2009.Therefore, it was concluded that the years 2000-2009 were the peak period of immigrants in Ulaanbaatar.

Acknowledgement
This study was supported by 2022-2024 basic research project "Spatial patterns and influencing factors of internal population migration in Mongolia" and I would like to thank the leader of the project, Dr. M.Altanbagana and the researchers in the field.
Davaanyam et al. (2023) in the report entitled "General Project of Population distribution and settlement development of Mongolia" In addition, a researcher B.
statistical indicators of population migration in Mongolia and Ulaanbaatar and the changes in the last 30 years (from 1990 to 2019) were analyzed in this study.The main sources of the key indicators of population size, growth, and migration are the Population and Housing Census, which is conducted once every 10 years by the National Statistics Office, as well as the end-of-year data on resident population and migration population reports.Indicators were collected from the Statistical Yearbook of Mongolia and the statistical database from the site www.1212.mnat the province and capital levels for the years 1990-2019, and initial data processing was done on MS Excel to create a database.
of migration b -Number of in-migrants c -Number of out-migrants d -Population b(k) -Ratio of in-migrants b -Number of in-migrants d -Population c(k) -Ratio of out-migrants c -Number of out-migrants d -Population - = ( − ) + ( − ) (4) Pt -Population of the last year Po -Population of the first year B -Total births D -Total deaths PMAS Proceedings of the Mongolian Academy of Sciences 6 in 2003, to a peak of 74.4 in 2004, from 33.9 to 40.2 in 2005 to 2009, and to 46.8 in 2010,from 27.9 to 31.7 in 2011-2016, which sharply decreased to 8.9-15.4 in 2017-2019.