Please briefly describe the reasons why China's population is concentrated in the east from the aspects of natural conditions and social economy.

Section 1 General situation of population distribution

I. Basic characteristics of population distribution

According to the results of the third national census in July 1982, China's total population is1031890,000 (including Taiwan Province province1827,000, Jinmen Mazu Island 58,000 and Hong Kong and Macao compatriots 5.38 million). In other words, 6.4% of the world's land area is inhabited by 20.6% of the world's population. The population problem in China has attracted worldwide attention.

The population density of China is 1 14.4 people per square kilometer (1987), but the actual population density varies greatly among 9.6 million square kilometers. The regional distribution of population is the basic aspect of a country's population characteristics. It is of great practical significance to study the characteristics of population distribution in China and reveal the law of population distribution for formulating regional population policies, carrying out land development and environmental governance.

Population distribution is influenced and restricted by natural conditions, economic development and social and historical factors. Different levels of regional economic development have led to significant differences in population distribution across China. Summarizing the regularity of population distribution in China, there are the following outstanding features.

1, the population is gradually sparse from the southeast coast to the northwest inland. The distribution of population in China is extremely uneven. Most of the population is concentrated in the southeast, and the population in the western half is sparse and scattered. If a straight line is drawn from Heihe City on the border of Heilongjiang Province to Ruili County on the border of Yunnan Province, the area to the east of this line accounts for about 43% of the whole country, but the population accounts for 94.3% of the whole country, while the area to the west of this line accounts for about 57% of the whole country and the population accounts for only 5.7% of the whole country (Table 4- 1).

The reason for this feature is that the topography of the southeast coastal areas is dominated by plains (including the three major plains in China) and hills. Except for some peaks, the altitude is mostly within 500 meters, and the plain is generally within 200 meters. Low terrain and fertile land. Bordering the Pacific Ocean, the coastline stretches 18000 km, which is deeply influenced by the ocean, with a remarkable monsoon climate, mild climate and abundant precipitation. These favorable conditions have promoted economic development and population gathering. Since the Eastern Jin Dynasty in the 4th century A.D., in addition to the original Central Plains, the southeastern region of China has been gradually developed and its population has increased rapidly. Especially in modern times, due to the invasion of imperialist forces, with the abnormal development of colonial economy and productivity distribution, some parts of southeast China are highly densely populated. After the founding of New China, in order to make China's population distribution and productivity distribution more reasonable, promote national and inland economic development, strengthen national defense construction, and support the development of border minority areas, the state gradually changed the extremely unbalanced population distribution among coastal areas, inland areas and remote areas by adjusting the investment ratio between inland areas and coastal areas, organizing the population migration from coastal areas to inland areas, and formulating population policies suitable for different areas.

2. The plain area is densely populated, and the population decreases with the elevation of the terrain. The population distribution in China is extremely uneven in the horizontal direction, but it also shows a dense population in the plain area in the vertical direction. From the plain to the surrounding hills, plateaus and mountains, there is a law that the population decreases with the increase of topography. If we compare the population distribution map of China and the population density map of China with a topographic map, we will see this feature clearly and vividly.

From a national perspective, the terrain of China is high in the west and low in the east, which is roughly three steps. The Qinghai-Tibet Plateau is located in the west of China, with an average elevation of more than 4,000 meters, which is the first step of China's topography. The mountains on the plateau are juxtaposed and the ice peaks overlap, which is known as the "roof of the world". In the northern and eastern parts of the Qinghai-Tibet Plateau, huge mountains alternate with vast plateaus and basins, forming the second step of China's topography. The larger plateaus are Inner Mongolia Plateau, Yunnan-Guizhou Plateau and Loess Plateau. There are Tarim basin, Junggar basin and Sichuan basin. The third step is from Daxing 'anling, Taihang Mountain and Wushan to the east of the eastern edge of Yunnan-Guizhou Plateau. The terrain is dominated by plains and hills, and the altitude is mostly below 500 meters. The population distribution in China decreases with the elevation of the terrain, and it also tends to decrease from east to west.

However, there are many kinds of landforms in China, including plains, hills, mountains, plateaus and basins, and all kinds of landforms are intertwined and complicated, which leads to obvious local differences in population distribution in various regions of China on the basis of the above macro characteristics and laws. The plains and hills below 500 meters above sea level in China account for 22% of the total land area, but nearly 4/5 of the country's population is concentrated. Plains and hills are the main distribution areas of population in China (Table 4-2). The vast majority of the population in China is located in low-lying areas below 500m, which is consistent with the basic trend of population distribution in the world. However, at the altitude of 1000m-2000m, the population proportion is relatively high, which is mainly due to the plateau of the Loess Plateau, the Sichuan Basin between the hills and the headlands, many large and small basins (bazi) on the Yunnan-Guizhou Plateau, the Hetao Plain in the Inner Mongolia Plateau, and the Yinchuan Plain. Located at this altitude is a developed agricultural area with a dense population. The population at the altitude of 500- 1000 meters is obviously low, because it has an area of about 1/3 distributed in the western part of China, such as arid semi-desert and desert areas such as Xinjiang and Inner Mongolia, and the population is extremely sparse or uninhabited. Above 2000 meters, it is mainly the plateau and alpine zone, and most of the ethnic minorities in remote areas of China are located in this altitude zone. For example, Tibetan compatriots living on the Qinghai-Tibet Plateau have adapted to the environment of the plateau and mountainous areas through long-term life and labor, and have become world-famous plateau peoples. At present, the highest residential area in Tibet has reached 4880 meters above sea level, which is also rare in the world. The population density in this altitude area is relatively low.

Terrain and altitude have a significant impact on population distribution, because the temperature and air pressure decrease with the increase of altitude, which directly restricts people's physiological functions and life activities. With the increase of height, cold, strong wind, less heat, short growth period, less flat land, more sloping land, poor soil layer and inconvenient transportation not only deeply affect agricultural production, but also are unfavorable to other economic activities. Therefore, the population in mountainous areas and plateaus is less dense than that in plain areas, and the greater the fluctuation of altitude and topography and the steeper the slope, the more obvious this disadvantage is.

The vast majority of the population is distributed in rural areas. Due to historical reasons, China's industrial production level is not high, urbanization level is low, the proportion of urban population is small, and agriculture still dominates the economic activities of the people throughout the country. This is the characteristic of China's current economy, and it is also a sign of the current level of productivity development. This situation has played a decisive role in the basic characteristics of population distribution in China.

1982 The results of the third national census showed that the population living in rural areas accounted for 77.9% of the total population, with a total population of 803.86 million, of which 96% were engaged in agriculture.

According to relevant statistics, there are more than 4.5 million rural settlements (or natural villages) in China, with an average of 180 people per settlement. According to the land area of China, there is a village every 2. 13 square kilometers, with an average interval of 0.68 kilometers. But in fact, the scale and density of rural settlements in different regions of China vary greatly in regional distribution, and the distribution law is related to natural geographical conditions, production structure and methods, historical traditions and other factors. In the northern plains of China, such as the Northeast Plain and the North China Plain, rural settlements are large, and there are many large villages with more than 1000 people. For example, Rongcheng County in Hebei Province has an average population of 1.200, and there are about 30-80 villages per 100 square kilometers. In most areas of the middle and lower reaches of the Yangtze River in the south, villages are small in scale, with an average population of 1 200-200 people. There are more than 100 villages per 100 square kilometers, such as 400-700 in Taihu Lake Basin, 470 in Wujin County, Jiangsu Province, and more than 700 in Jiading County, Shanghai. In hilly areas, the scale of rural settlements is generally smaller than that of nearby plain areas, such as hilly areas in eastern and central Sichuan, hilly areas in the south of the Yangtze River, hilly areas in Zhejiang and Fujian, etc. And a large number of settlements are just small villages with less than 20 households. Scattered villages are caused by narrow and scattered agricultural land. In the vast arid areas of western China, rural settlements are not only small in scale, but also sparse in density. Most large-scale animal husbandry areas are inhabited by only a few families. There are dozens or even hundreds of villages in irrigated agricultural areas such as Hexi Corridor, Xinjiang Oasis and Lhasa Valley alone.

In short, in the eastern part of China, the terrain is low, the economy is developed and the rural population is dense; The mountainous areas in the western region are widely distributed, with little land and water, and the rural population is sparse. However, the spread of rural population is a common feature of the whole country.

Second, densely populated areas.

The imbalance in the geographical distribution of population in China is also manifested by great local differences. Some areas are densely populated and some areas are extremely sparsely populated. From a national perspective, the most striking densely populated areas are:

1, the lower reaches of the Yangtze River and the coast of Hangzhou Bay

Including the Yangtze River Plain, Chaohu Lake Plain, Yangtze River Delta, Taihu Lake Plain and the banks of Hangzhou Bay below Anqing City, Jiangxi Province. With a population of over 70 million and a total area of about 90,000 square kilometers, this area has gathered 20 cities and 85 counties including Shanghai, Nanjing, Hangzhou and Suzhou. The population density is as high as 778 people per square kilometer, which is the area with high population density in China. The population in this area is most concentrated along the Shanghai-Nanjing, Shanghai-Hangzhou and Hangzhou-Ningbo railways and along the Yangtze River estuary. This fertile plain has good conditions for developing production and a long history of development. At present, industrial and agricultural production is very developed and plays an important role in the economic development of China.

2. Huang Huai Hai Plain and Shandong Peninsula

Including the Yellow River, Huaihe River, the lower reaches of Haihe River and Shandong Peninsula, there are more than 40 cities and 380 counties in the jurisdiction, including Beijing, Tianjin, Shijiazhuang, Jinan and Zhengzhou, covering an area of about 500,000 square kilometers, with a total population of over 250 million and a population density of 500 people per square kilometer. The area is densely populated, especially along the Jingshan and Beijing-Guangzhou railways in Hebei Province. Eastern Henan is the Luoyang-Zhengzhou-Xuchang-Zhoukou line; The population along the Yellow River and the Grand Canal in Luxi and Shandong Peninsula is the most concentrated. It has a mild climate, low terrain and a long history of development. Known as the cradle of the birth of the Chinese nation, it has long been a gathering place of China's economy and culture.

3. Sichuan Basin

The area is about 1 0.5 million square kilometers, with a population of more than 70 million and a population density of 538 people/square kilometers, including Chengdu, Chongqing, Yibin and Luzhou1city and 95 counties. Chengdu Plain and other places in the region have a long history of agricultural development and superior natural conditions, enjoying the benefits of Dujiangyan water conservancy project at home and abroad and enjoying the reputation of "Land of Abundance" for a long time. The population around Chengdu Plain and Chongqing is relatively concentrated. The climate in Sichuan Basin is warm and humid, and it has been one of the developed agricultural areas in China for more than 2000 years.

4. Plain in the middle reaches of the Yangtze River

Including Nanyang Basin in Henan Province, Jianghan Plain in Hubei Province, Dongting Lake Plain in Hunan Province, banks of Xiangjiang River in Jiangxi Province and Poyang Lake Plain, covering an area of about 240,000 square kilometers. The population is more than 80 million, and the population density is 333 people per square kilometer. There are 20 cities such as Wuhan, Changsha, Zhuzhou and Nanchang in the jurisdiction, and 120 counties. This area is one of the agricultural areas with a long history in China. After the founding of People's Republic of China (PRC), the industry has developed greatly, and it has become a new type of economically developed and densely populated area in China.

In addition, there are some small-scale densely populated areas, such as the Pearl River and Hanjiang Delta in the southeast coastal zone and the coastal plains in central Fujian, central Zhejiang and western Taiwan. Guangzhou, Foshan, Shenzhen, Jiangmen, Zhuhai, Hong Kong, Macau, Fuzhou, Xiamen, Shantou, Wenzhou, Taipei, Kaohsiung and many other large and medium-sized cities are located in this area. Secondly, the population density in the middle and lower reaches of Weihe River and Fenhe River and the central and southern parts of Liaoning Province is relatively high.

Three. Areas with no residents and few residents

At present, China still has a land area of1855,000 square kilometers, accounting for about 19.32% of the national area. Due to the harsh natural conditions, it is still difficult to transform and utilize, and it is not suitable for human living and living, making it a non-populated area. A large area of no man's land in China is mainly located in the western half, including Qiangtang Plateau, central Tarim Basin and Alashan Plateau.

1, Qiangtang Plateau

The northern Tibetan Plateau, also known as Qiangtang Plateau, covers an area of 580,000 square kilometers with an average elevation of more than 5,000 meters. The ice peaks are green, the snow-capped mountains are continuous, and the climate is extremely dry and cold. It was once called "dry and cold core" and "land of death". The annual average temperature is below -8℃, the most Leng Yue average temperature is below-12℃, the hottest month is below 12℃, the annual precipitation is below 150mm, and the daily average temperature is not more than 2 months. On average, there is 1 settled population every 60 square kilometers. It can be said that this area is basically uninhabited.

2. Central Tarim Basin

Located in the north of Qinghai-Tibet Plateau and the south of Xinjiang. In the middle of the huge basin surrounded by Pamir Plateau, Kunlun Mountain and Tianshan Mountain, there is a vast Taklimakan Desert, which is connected with Kumtag Desert and Gashun Gobi Desert, covering an area of about 330,000 square kilometers. It is the driest area in China, with annual precipitation less than 15mm and dryness as high as 80. ① The daily average temperature difference is often around 20℃. Throughout history, this desert has always been an uninhabited world except for Chinese and foreign explorers and expeditions who have participated in it for nearly a hundred years.

3. Deserts and Gobi in western Inner Mongolia

It starts from Wushaoling-Helan Mountain in the east and reaches Shule River in the west. It is a vast area of 290,000 square kilometers north of the Great Wall, stretching from east to west 1000 kilometers. That is the world of quicksand Gobi. The annual precipitation is between 50-200mm, the climate is dry, the sandstorm is rampant and the vegetation is sparse. Almost no one has settled in history.

Fourth, the difference and division of population density.

Population density refers to the number of people living per unit land area in a certain period, and it is an important indicator to explain the regional population, usually expressed by the number of permanent residents per square kilometer. It's just an average. Generally speaking, the smaller the statistical unit, the smaller the difference between natural conditions and economic conditions in the unit, and the closer the quantitative indicators reflected are to the actual situation. When investigating population density, we should not only analyze the ratio of total land area to population, but also pay attention to the "economic density of population", such as cultivated land area and population, resource reserves and population, output (or output value) and population, national income and population. In practical sense, the size of economic density of population can better reflect the reasonable degree of population distribution in a region, as well as the relationship and constraints among population, resource conditions and economic development. Because population distribution and its change can not be separated from certain social and economic background and specific environmental conditions at any time, in order to actively establish a more coordinated and reasonable relationship between economic development and population development, it is necessary to study and evaluate the characteristics of population density in various regions, thus providing a comprehensive scientific basis for the establishment of the above relationship.

1, the difference of population density among provinces.

Besides Shanghai, Tianjin and Beijing, the provinces and cities with the highest population density in China are Jiangsu, Shandong and Henan. The above three provinces and cities are located in the eastern coastal areas and areas dominated by plains. The provinces with the lowest population density are Xizang Autonomous Region, Qinghai and Xinjiang Uygur Autonomous Region, which are distributed in remote areas with poor natural conditions in western China. The population density of Heilongjiang and Yunnan provinces in the eastern frontier is lower than the national average. The population density varies greatly among provinces and regions. For example, Shanghai with the highest population density has an average of 2044 people /km2, while Xizang Autonomous Region with the lowest population density has an average of 1.57 people /km2, with a difference of 1.302 times. Excluding the three municipalities directly under the central government, the average density of Jiangsu, Shandong and Henan provinces with the highest population density is 494.3 people /km2, compared with Xizang Autonomous Region, Qinghai and Xinjiang Uygur Autonomous Region with the lowest population density. Looking further by county, the population density in some parts of China is the highest in Chenghai County, Guangdong Province, with 0/.752 people per square kilometer, and the lowest in Ritu County, Xizang Autonomous Region, with only 0.066 people per square kilometer, with a difference of 26,553 times. According to statistics, there are 17 counties with an average population density of more than 0/000 people per square kilometer, including 4 counties in Guangdong, 4 counties in Shanghai, 3 counties in Zhejiang, 2 counties in Fujian and Taiwan, and 0 counties in Sichuan and Jiangsu. The total area of these 17 counties is12,643 square kilometers, accounting for 0. 13% of the national total area, but there are14.45 million people, accounting for10.44% of the national total area. On the other hand, there are 34 counties in China whose population density is lower than per square kilometer 1 person, including 6 counties in Tibet/kloc-0, 8 counties in Qinghai, 5 counties in Xinjiang, 3 counties in Inner Mongolia and 2 counties in Gansu. Area 1.96 thousand square kilometers, accounting for 20.4% of the country, while the population is less than 590 thousand, accounting for only 0.058% of the country's total population. The average population density is more than 3000 times different from the top 65,438+07 counties with the highest population density.

2. Per capita economic indicators and population density of each province

(1) Regional differences and population density of cultivated land per capita. Cultivated land is the most basic material basis for agricultural production and the basic condition for regional industrial and agricultural development. The amount of cultivated land per capita affects the development of the whole economy and the improvement of people's material living standards. The total cultivated land area in China is about 654.38+05 billion mu, accounting for 654.38+00.4% of the national territory. According to the national average, the per capita arable land is about 654.38+0.36 mu, which varies greatly among provinces. Beijing, Shanghai and Tianjin and Zhejiang, Fujian, Hunan and Guizhou provinces have the least arable land per capita, with an average of less than 1 mu. The provinces with the largest cultivated land per capita are Heilongjiang Province, Xinjiang and Ningxia, and the cultivated land per capita in these three provinces exceeds 3 mu. The per capita cultivated land quantity in each province is obviously restricted by population density and cultivated land quantity. As shown in Table 4-3, provinces with high population density and less cultivated land have less cultivated land per capita, while provinces with low population density and more cultivated land have more cultivated land per capita.

As can be seen from the table, the population density of provinces with per capita arable land less than the national average is greater than the national average, while the population density of provinces with per capita arable land greater than the national average is less than the national average. We can also compare the proportion of cultivated land to population in each province. Generally speaking, the proportion of population in provinces with less cultivated land per capita is greater than that in the whole country, while the proportion of population in provinces with more cultivated land per capita is less than that in the whole country. On the other hand, in terms of absolute quantity, the per capita arable land in all provinces and regions of China is generally low, which is caused by China's large population and high population density, while the total area of arable land and the proportion of arable land in the land area are small.

(2) Regional differences and population density of per capita grain. According to 1982 agricultural production statistics synchronized with the census, 1982 was a bumper harvest year, in which the national average grain reached 685 Jin. Judging from the specific situation of each province, there are five provinces, including Jiangsu, Zhejiang, Hunan, Hubei and Jilin, where the per capita grain exceeds 800 kg. Except for the three municipalities directly under the central government, Guizhou, Tibet, Gansu and other provinces and regions have the least per capita grain, and the per capita grain is less than 500 Jin. This difference between provinces is directly related to factors such as population density, natural conditions, production level, departmental structure of agricultural production and tasks undertaken in regional division of labor across the country. Provinces with more grain per capita are those with superior natural conditions and high production level, such as Jiangsu, Zhejiang, Hunan and Hubei. Although the population density of these provinces is high, the per capita arable land is lower than the national average, and some even have a per capita shortage of 1 mu, but the production level and favorable natural conditions have played an important role; The other is that the production level and natural conditions are better, the population is sparse (or less), and the per capita cultivated land is more, such as Heilongjiang and Jilin. Guizhou, Tibet, Qinghai and Gansu provinces have low population density and more arable land per capita, but the natural conditions are poor and the production level is low, so they are the provinces with less grain per capita in China.

The amount of food that a region can provide to its residents is the basic material premise that restricts the population size and population density in this region. Judging from the actual situation in China, the difference of per capita grain in different regions is greatly influenced by the level of agricultural production in different regions. Only with the development of production level, the productive potential of land is continuously explored and improved, and the unbalanced population distribution in China will be gradually improved.

(3) Regional differences in per capita industrial and agricultural output value and population density. The per capita agricultural output value of each province in China is calculated according to the average of pure agricultural population, which varies greatly among provinces, but is generally low, reflecting the low level of agricultural productivity in China. The provinces and regions with the highest per capita agricultural output value are Shanghai, Heilongjiang, Jiangsu and Jilin, all exceeding 400 yuan/person, while the lowest are Guizhou and Gansu provinces, and the agricultural output value is less than 200 yuan/person. In terms of per capita industrial and agricultural output value, Shanghai, Tianjin and Beijing are the highest, followed by other provinces, Liaoning, Jiangsu and Heilongjiang, with per capita over 654.38+10,000 yuan. The lowest per capita industrial and agricultural output value is Guizhou, as well as Yunnan and Guangxi Zhuang Autonomous Region. Height difference 16 times. The main reason for the obvious difference lies in the difference in the level of urban industrial development and the proportion of urban and rural population between provinces. For example, in addition to the three municipalities directly under the central government, the proportion of urban population in Liaoning Province and Heilongjiang Province reaches 35%, and the industrial output value also accounts for a large proportion. Although the urban population in Jiangsu Province is not prominent, small and medium-sized cities and township enterprises are developed, which not only have a large number, but also have high labor productivity, making the industrial and agricultural output value of Jiangsu Province second to none in the country, reaching 73.6 billion yuan. The low level of industrial development and the small proportion of urban population in Guizhou, Yunnan and Guangxi provinces are the main reasons for the low per capita industrial and agricultural output value in the three provinces.

The population density characteristics of provinces, municipalities and autonomous regions are as described above. In fact, there are great differences among counties in many provinces and regions (Table 4-4). The larger the general area, the more complicated the situation and conditions, and the more obvious the difference.

(4) Population density zoning. According to population density, per capita arable land, per capita grain and per capita industrial and agricultural output value, 29 provinces and regions in Chinese mainland are divided into 6 types. ① Areas with high population density A. Cultivated land types with low and high yield are: Beijing, Tianjin, Shanghai, Jiangsu, Zhejiang, Liaoning, Jilin, Shandong, Guangdong, Hubei and Hunan. B The types of low-yield cultivated land are: Anhui, Henan, Jiangxi, Guizhou, Guangxi, Fujian and Sichuan. C. Types with more cultivated land and higher output are: Shanxi, Hebei and Shaanxi. ② Areas with low population density: A. How high is the cultivated land? The output types are: Heilongjiang. From the current situation and development potential, Inner Mongolia and Xinjiang also belong to this type. B the types of cultivated land with low yield are: Ningxia, Qinghai, Gansu and Tibet. C. Types of low-yield cultivated land are: Yunnan.

Whether in high population density areas or low population density areas, to complete the transformation from low output type to high output type, we must start from two aspects: population control and production development. On the one hand, it is necessary to strictly implement family planning and control the population growth in high population density areas; On the other hand, it is necessary to strictly control urban and rural construction land and resolutely stop the indiscriminate occupation of cultivated land for any reason. Develop production, speed up urbanization and improve labor productivity. In areas with low population density, family planning should also be strictly implemented to control the free growth of population, but it is necessary to encourage the inflow of talents and accelerate the mechanical growth of population. Strive to realize urbanization, develop production according to local conditions, and accelerate the moderate population size.