Environmental structure of world geography

Geographical environment is a unified whole, and its components are interrelated and mutually restricted. For example, due to climate warming, Quaternary glaciers retreated, causing sea level rise and coastal changes; On land, it causes the changes of ground shaping process, weathering mode and pedogenesis, and the movement of plants and animals to the north (in the northern hemisphere) or south (in the southern hemisphere). The change of desert area on the west coast of South America provides a vivid example of the close relationship between various parts of the geographical environment. Under normal circumstances, this area is characterized by drought in climate, topography, hydrological characteristics, soil and vegetation lifestyle. This is mainly due to the downdraft at the eastern edge of the subtropical high in the South Pacific and the cold current along the coast. However, in the year when the trade winds in the western Pacific reversed, a warm current under the water surface flowed to the eastern Pacific along the equator, which caused the sea surface on the west coast near the equator in South America to rise, and the temperature and thickness of the surface warm water increased, so a huge amount of surface warm water flowed from the equator along the coast of Ecuador to Peru, in which the coastal temperature and precipitation increased significantly, resulting in corresponding changes in hydrology, animals and plants, and the regional comprehensive characteristics changed from drought to humidity. This abnormal phenomenon occurs roughly once every two or three years or four or five years.

The earth is spherical, and the distribution of sunlight and heat on the surface changes with latitude; Secondly, the composition of the earth's surface is not uniform, and the surface structure is also different, such as the complicated distribution of land and sea, the ups and downs of the ground and so on. Therefore, there are differences among the various components of the geographical environment. Due to the former reason, it is characterized by zonal differences. From the equator to the poles, various geographical elements generally show the differentiation pattern of east-west extension and north-south replacement, thus combining into a series of natural zones; Because of the latter reason, it is manifested as non-zonal difference, so the zonal law is deviated or even covered up. These two differentiation laws are opposite to each other and penetrate each other. The complex picture of the global natural geographical environment is the embodiment of their unity of opposites. The zonal and non-zonal differences of the whole geographical environment are reflected in different degrees and contents on each continent, which is a comprehensive reflection caused by the differences in latitude position, land and sea position, continental outline and area size, topographic structure and even historical development process, thus giving each continent a unique physical geography. Clarifying the uniqueness of a continent is of great significance for understanding and discussing the structure of the global geographical environment. The uniqueness of any continent different from other continents not only reflects the integrity of the continent, but also reflects the differences of the whole geographical environment.

The following only summarizes the uniqueness of the main components of geographical environment (mainland and ocean) from the perspective of macro-comparison, aiming at revealing the heterogeneity of global geographical environment structure. brief introduction

Asia is the largest continent in the world, living in the east of Eurasia, facing the world's largest ocean Pacific Ocean, spanning all latitudes from the equator to the North Pole. So, first of all, what distinguishes Asia from other continents is almost complete climate zone, complex and diverse climate types, strong continental nature and typical monsoon. In addition to the maritime climate on the west coast of temperate zone and polar ice sheet climate, there are many climate types such as cold zone, temperate zone, subtropical zone and tropical zone. Compared with other continents at the same latitude, the vast inland and high-latitude areas generally have the characteristics of high annual temperature and high concentration of annual precipitation in summer. Asia is famous for being one of the coldest, hottest, driest and wettest regions in the world. The extreme change of climate elements is another important reflection of strong continental climate. In the monsoon climate regions of East Asia, Southeast Asia and South Asia, the seasonal variation characteristics of temperature, precipitation and wind direction are distinct and widely distributed, including temperate monsoon climate, tropical monsoon climate and subtropical monsoon climate in transition, which has unique significance in the world. The polar long cold climate (tundra climate) and the north Asian continental climate (coniferous forest climate) cross the continent from east to west, covering a wide area; Most parts of Central Asia and West Asia have temperate, subtropical and tropical arid climates, and the area of arid areas is equivalent to that of Africa. The terrain is complex and undulating, with an average elevation of 950 meters. Mountains and plateaus account for about 3/4 of the whole continent.

Generally speaking, Asia straddles tropical and temperate zones, borders the ocean on the east, north and south, and the central and western regions live in the hinterland of the Asian continent. Influenced by latitude, land and sea location and topography, the Asian climate is characterized by complexity and diversity, widespread continental climate and remarkable monsoon climate.

Basic topographic map

(1) Mountains are mostly concentrated in the south-central, closely combined with mountain plateaus and basins, forming a huge towering zone across the east and west, namely Qinghai-Tibet Plateau, Pamir Mountain Knot, Iranian Plateau, Armenian Mountain Knot and Anatolia Plateau, as well as Qilian Mountain, Kunlun Mountain, Hindu Kush Mountain, Irpur Mountain and Gogasso Mountain in the north and Himalayan Mountain, Karakorum Mountain, Suleiman Mountain and other mountains in the south. From the Pamirs to the northeast, the Tianshan Mountains and Altai Mountains sandwiched between the Tarim Basin and Junggar Basin pass through the mountains on the north and south sides of the Mongolian Plateau and are connected with the mountains in eastern Siberia.

(2) The terrain descends from the middle to the surrounding areas to the middle and low mountains, hills and plains, and the Turan Plain and the Western Siberia Plain are low in the northwest, and there are gentle Kazakh hills and the Central Siberia Plateau cut by rivers to the east of the plain. On the three southern peninsulas, eroded ancient plateaus and modern river alluvial plains are alternately distributed. From west to east, it is the Arabian Plateau, Mesopotamia Plain, Deccan Plateau, Indus-Ganges Plain, Shan Plateau and Mekong Plain. The terrain descended to the east in a ladder shape, and finally fell to the low hills in the east of China and the alluvial plains in the northeast, north China and the middle and lower reaches of the Yangtze River.

The eastern edge of Asia is a series of arc-shaped islands protruding into the Pacific Ocean, most of which are occupied by young folded mountains, and the outer side is adjacent to deep ditches. Under the comprehensive influence of topography and climate, the layout of river network presents the characteristics of asymmetric radiation. Affected by topography, most rivers in Asia originate from the central mountainous areas and plateaus, and flow radially to the surrounding oceans, with a long history. Most of the rivers in Sichuan originate from the towering middle and flow around. Except inland rivers, they flow into the Arctic Ocean, the Pacific Ocean and the Indian Ocean respectively. The river network is dense, and most of them belong to rivers in summer. These rivers have a long history. Ob river, Yenisei River, Lena River, Heilongjiang River, Yangtze River, Yellow River and Mekong River are all over 4,000 kilometers in length, of which the Yangtze River is 6,300 kilometers, making it one of the three longest rivers in the world. Their upstream passes through the mountains, forming many deep valleys with fast flowing water; The lower reaches are alluvial into a vast plain and estuary delta. The internal flow area is vast, accounting for about 30% of the total area of the whole continent, and the absolute area ranks first among all continents, mainly distributed in Central Asia and West Asia. It is inland, with dry climate and relatively closed terrain. There are no large freshwater lakes in the whole continent, but there are many kinds of lakes, many of which are world-famous. For example, the Caspian Sea is the largest lake in the world, Lake Baikal is the deepest lake in the world, and the Dead Sea is the lowest point of lakes and land in the world. As an important symbol of Asian geographical environment, vegetation and soil not only reflect the complex diversity in type composition, but also reflect the differentiation pattern of the geographical environment of the whole continent in its distribution and replacement pattern. The tundra-glacial swamp soil and coniferous forest-calcareous soil in North Asia are part of the same type of zone in the northern hemisphere, extending from east to west and alternating with north and south, reflecting obvious zonal differentiation law. Since then, due to the interference of non-zonal factors such as topography and distance from the sea, it has been divided into two different replacement sequences: coastal (East Asia-Southeast Asia) and inland (Central Asia). The former are mainly temperate deciduous broad-leaved forest-brown soil, subtropical evergreen broad-leaved forest-red soil and yellow soil, tropical monsoon forest-lateritic soil and tropical rain forest-latosol; The latter is adapted to dry and wet changes, mainly including temperate forest grassland-gray forest soil, temperate grassland-chernozem and chestnut soil, desert grassland-brown grassland soil, arid desert-calcareous soil and desert soil. There are also different vertical zonal structures in alpine and plateau areas. In a word, Asia, as the largest natural complex in the world, highlights the diversity and extremes of various geographical elements, and forms its unique geographical environment structure through the eclectic and intricate cross-relationship between zonal differences and non-zonal differences. The North American continent is clearly divided into three topographic longitudinal zones:

① Cordillera mountain system, which consists of a series of mountains, mountain plateaus and basins, is located in the western part of the mainland, with wide mountain system, high height and complex terrain;

(2) There are Appalachian highlands with long erosion time and medium height in the east of the mainland, which are northeast-southwest trending;

(3) Between the above two zones, the Laurentian low plateau and the flat central plain are shown. The topographic structure of stone pillars has great influence on the climate, water system, soil and vegetation distribution in mainland China.

The temperate continental climate is dominant, and Leng Xia is warm in winter in most areas, with high annual temperature variation. The annual precipitation is moderate, mainly in summer rain. However, North America is not as good as Asia in terms of extreme temperature changes, concentration of rain in summer and drought in winter. North America, from the cold zone to the tropical zone, from the east coast to the west coast of the mainland, has diverse climate types, which are comparable to those of Asia in terms of type diversity and have their own characteristics. There is no typical monsoon climate in East Asia in eastern North America, but it is replaced by temperate continental humid climate, subtropical humid climate and tropical maritime climate. North America has a polar ice cap climate and a temperate maritime climate on the west coast that Asia lacks, but the tropical climate is limited, basically lacking a typical equatorial rainy climate, and the tropical arid and semi-arid climate is not as widely distributed as Asia. Generally speaking, sub-frigid continental climate, temperate continental arid and semi-arid climate and temperate continental humid climate are the most widely distributed in North America, accounting for more than half of the total mainland area. Under the influence of topographic structure and climate, the regional differentiation of river network distribution and the scale and degree of water system development also have distinct characteristics. The outflow area is absolutely dominant, which is quite different from the inflow area. If frozen Greenland is not included, they account for 96.7% and 3.3% of the whole continental area respectively. Most of the rivers in the outflow area originate from Rocky Mountain, the main watershed of the mainland. Together with the Appalachian highland in the east and the moraine area in the north-central part, it forms a slightly H-shaped watershed pattern, with rivers flowing south, east and west, and the major river basin systems are obviously compared. Among them, the south-central part of the Gulf of Mexico basin system is a hydrological region with dense river networks in North America. The Mississippi River, the longest river in the mainland, is a huge water system with vast plains, abundant precipitation, converging runoff and a long history of development. Most areas were not invaded by Quaternary glaciers. After the Great Ice Age, the Missouri River and the Ohio River were accepted, which further strengthened the development of the whole water system. There are large water systems in the west, such as yukon river River, Columbia River, Colorado River and Rio Grande River (bravo river), most of which flow through arid and semi-arid mountainous areas, with many canyons and rapids, and the development of water systems shows a certain rejuvenation. There is the mackenzie river in the Arctic Ocean basin system, which is the second longest river in the whole continent. The freshwater lake area in North America is the largest in all continents, and it is famous for its numerous lakes and glaciers. In the north, Great Bear Lake, Great Slave Lake, Winnipeg Lake, Lake Superior, Lake Michigan, Lake Huron, Lake Erie and Lake Ontario are arranged in an arc, forming the largest lake belt and freshwater lake group in the world. The composition of vegetation-soil types in North America reflects the diversity of climate types, and almost all vegetation-soil types on the earth exist on this continent. On the whole, coniferous forest-calcareous soil has the widest distribution area, accounting for more than all continents in the world. Secondly, the distribution of ice sheet and tundra-glacial marsh soil is also prominent in all continents of the world, the former is second only to Antarctica, and the latter is similar to Asia. However, the proportion of tropical vegetation-soil is very small both in absolute area and in the whole continent, and desert vegetation-soil is also secondary. The distribution of vegetation-soil types is basically consistent with the structural pattern of climate types, reflecting the interaction of zonal and non-zonal factors. In the northern high latitudes, the ground does not fluctuate greatly, and the hydrothermal conditions change gradually from north to south. The ice sheet, tundra-glacial swamp soil and coniferous forest-calcareous soil are replaced in turn, which are components of the corresponding natural zones in the northern hemisphere. Entering the mid-latitude area to the south, roughly bounded by 98 west longitude, the east and west not only have their own climate and vegetation-soil types, but also have opposite arrangement patterns. The ground in the east is relatively developed, mostly flat plains, low plateaus or highlands. The temperature and precipitation increased to the south, and the replacement sequence of temperate coniferous and broad-leaved mixed forest-gray brown soil, temperate deciduous broad-leaved forest-brown soil and subtropical evergreen forest-red soil or yellow soil appeared in turn. The west is located inland, and the mountains run through the north and south. The Great Plain is suitable for the rain shadow zone of Rocky Mountain, and the precipitation decreases from east to west. The vast mountain plateaus and basins to the west of Loki Mountain belong to semi-arid or arid climate, so the distribution pattern of vegetation-soil types presents a pattern of alternating east and west and extending north and south, followed by forest grassland-leached black soil, high grassland-chernozem, short grassland-chestnut soil, semi-desert or desert-calcareous soil or desert calcareous soil. Along the Pacific coast, the climate type changes from north to south from temperate ocean type to tropical drought type, and the vegetation-soil type changes from north to south and extends from north to south, which is a comprehensive embodiment of zonal structure and non-zonal structure. The isthmus of Central America and the West Indies in the south are located in the trade winds, and the mountains are parallel to the coast. The differentiation of climate-vegetation-soil types is mainly due to the difference between windward and leeward, which belongs to tropical maritime climate-tropical evergreen forest-latosol, red soil and tropical dry and wet season climate-tropical savanna-reddish brown soil. To sum up, all groups or elements of the geographical environment in North America are dominated by temperate types, which prominently reflects the continental characteristics of temperate zones; The zonal differentiation in the north and east and the non-zonal differentiation in the west and south form the unity of opposites, which constitutes the unique geographical environment structure map of North America. With social development, population growth, especially technological progress, the scope and depth of human utilization and transformation of geographical environment are constantly expanding. At the same time, the geographical environment has a more profound impact on human activities. The production of human material data is always carried out in a certain area. The nature, content and scale of productivity distribution are not only governed by social and economic laws, but also determined by the mode of production and restricted by natural conditions. Due to the great differences in area, population, natural conditions and natural resources among countries and regions in the world, the social system and development level are also different, and the socio-economic phenomenon of productivity distribution presents a complex scene.

/kloc-after the 0/7th century, the capitalist mode of production appeared in Europe and America, and capitalist factors sprouted in the economic forms of other countries. Several major scientific and technological revolutions have brought about great development of productive forces, and the world population has also increased rapidly. The world population is1600.545 billion, 61700.900 billion, 1900 1625 billion, with growth rates of/kloc-0.00 respectively. By 1984, the world population reached 4.763 billion, which increased by 193% in 1984. Population distribution is deeply influenced by natural conditions, but it also depends on the role of socio-economic conditions. The distribution of world population on all continents has never been balanced, and most of them are concentrated in the southern half of Eurasia and Africa. Although due to the growth and migration of population, especially the large-scale migration to America and Oceania in the last two or three centuries, the scope of human life on the earth is much wider than in the past, but the sharp imbalance of world population distribution has not been alleviated. The general characteristics are that the population in the northern hemisphere is more than that in the southern hemisphere, the coastal areas are more than the inland areas, and the plain lowlands are more than the mountain plateaus. The mid-latitude zone in the northern hemisphere has a large proportion of land, good climatic conditions, rich resources, a long history of development and a high level of productivity development. It is the most densely populated area in the world, with 20 ~ 40 N and 40 ~ 60 N accounting for about 50% and 30% of the world's total population respectively. On the other hand, 35 ~ 40% of the global land is basically uninhabited, and the area with less than 2 people per square kilometer accounts for more than half of the total area. Of all continents, Asia and Europe account for 58.3% and 16. 1% of the world's total population respectively, with the highest population density. Africa accounts for 1 1.3%, Latin America accounts for 8.3%, North America accounts for 5.5% and Oceania accounts for 0.5%. Among them, four densely populated areas, namely East Asia, South Asia, Europe and East North America, account for only 1/7 of the world's total land area, but account for two-thirds of the world's total population. Another important trend of population distribution in the world is the influx of rural population into towns, which has promoted the rapid development of urbanization. 1900, the proportion of global urban population was 13.6%, and 1984 rose to 4 1%, while the total area of all urban settlements was only 500,000 square kilometers, accounting for less than 0.4% of the total land area of the world.

The population in the world belongs to three major races, namely, Mongols, blacks and Europeans. Mongols, also known as yellow race or Asian-American race, are mainly distributed in East Asia, Southeast Asia, Siberia and Central Asia. Indians in America and Inuit (Eskimos) in the Arctic also belong to the yellow race. Black people, also known as black people, are mainly distributed in south-central Africa. Black people in the United States are descendants of slaves trafficked from Africa during the slave trade. Black people living in Australia, Pacific islands and the southeast edge of Asia are also called brown people or Malay-Polynesians. Europeans, also known as Caucasians or Caucasians, are mainly distributed in Europe, North Africa, West Asia and South Asia, and the descendants of white immigrants have also become the main components of the population in America, Australia and New Zealand. In addition, the communication and integration between the major races have formed many hybrids. Central and western Asia and northeast Africa are the combination of three major races, which have produced a series of transitional ethnic types since ancient times; In modern times, America and Oceania, which accepted a large number of immigrants, were also obviously mixed-race, among which Latin American mixed-race population accounted for more than half of the total population. Due to the differences in historical development, economic life, language and customs, many different nationalities have formed in different regions. There are more than 2,000 ethnic groups in the world, of which 29 are large ethnic groups with a population of more than 25 million, accounting for about two-thirds of the world's total population; There are more than 1400 ethnic minorities with a population of less than 65,438+10,000, accounting for less than 0. 1% of the world's total population. Some countries are single ethnic groups (such as Mongolia and North Korea) or two major ethnic groups are juxtaposed (such as Cyprus and Czechoslovakia), most countries are multi-ethnic (such as China and the Soviet Union), and some of the same ethnic groups are distributed in many countries (such as Arab ethnic groups).

There are over 200 administrative units in the world, including about 170 independent countries. According to the social system and the level of economic development, today's world is generally divided into three types of countries, namely developed capitalist countries, developing nationalist countries and socialist countries. They belong to capitalist economic system and socialist economic system respectively.

Developed capitalist countries include most countries in Western Europe, the United States and Canada in North America, Japan in Asia and Australia and New Zealand in Oceania. They account for 24% of the world's total land area and 16.6% of the world's total population. They are mainly distributed in the temperate zone of the northern hemisphere and are generally called "North" in the regional pattern of the world economy. With strong economic strength, the gross national product accounts for about two-thirds of the world total (1984), of which more than four-fifths are concentrated in seven big countries, such as the United States, Japan, the Federal Republic of Germany, France, Britain, Italy and Canada. The per capita GNP of most countries is above 10000 USD, while that of other countries is above 5000 USD. The remarkable feature of the structure of material production department is that the industrial output value is much higher than the agricultural output value; In the internal structure of the industry, the manufacturing industry occupies an absolute advantage, with heavy industry as the main industry, while the mining industry and textile industry account for a low proportion; Agricultural production is highly mechanized, intensive and commercialized, and labor productivity is high. The output value of animal husbandry is generally higher than that of planting. Judging from the occupational composition of the population, the proportion of the tertiary industry is above 50-60%, the proportion of the primary industry is less than 10%, and the proportion of the secondary industry is about 25-45%, showing a stable or declining trend. Among these countries, only a few countries, such as Canada and Australia, base their economic development on rich natural resources. Most countries are poor in resources, or rich in resources, but due to long-term development and excessive consumption, their dependence on foreign countries is getting higher and higher.

Developing nationalist countries are mainly distributed in Asia, Africa, Latin America, South Pacific and Mediterranean, accounting for 49.9% of the world's land area and 5 1. 1% of the world's total population. Most of these countries are located in the south of the above-mentioned developed capitalist countries and are generally called "South" in the regional pattern of the world economy. The level of economic development is generally low, and the gross national product accounts for about1/5 of the world total (1984). Except for some high-income oil exporting countries and newly industrialized countries, the per capita GNP is mostly below $65,438+$0,000, and in many countries it is below $400 or even less than $200. Rich in resources, agriculture and mining play a major role in the national economy, and many countries have not fundamentally changed the single economic situation left over from the colonial period; The manufacturing industry is weak and the textile industry is the main industry; Agricultural technology is backward, labor productivity is low, animal husbandry is extensive, planting is generally dominant, tropical cash crops for export account for a large proportion, and food is generally not self-sufficient In the occupational composition of the population, the proportion of the primary industry is generally above 35-40%, even above 80%, while the proportion of the secondary and tertiary industries is very low. In foreign economic relations, they are generally suppliers of agricultural and mineral raw materials and fuels in developed capitalist countries, and also dumping markets for industrial products.

The distribution of world productive forces, especially industrial production, has developed in the process of the unity of opposites between centralization and decentralization. The concentration of production areas is the inevitable result of the development of science and technology and productivity to a certain level; The transformation of production areas from high concentration to diffusion is also based on the high level of productivity development and the original production concentration areas. Worldwide, industries are mainly distributed in western Europe (such as Ruhr in West Germany, Paris in France and southeast Britain), North America (northeast America), Japan (south of the central Pacific coast) and the European part of the Soviet Union. After World War II, these areas developed further and reached a stage of high concentration. The production of factories and mines tends to be large-scale and joint, and a series of large economic centers and corresponding modern big cities have emerged. At the same time, the world industrial layout began a process of rapid outward expansion. Industries in southern and eastern Europe, as well as Canada and Australia, have developed rapidly. Some developing countries, such as Brazil, Mexico and Argentina in Latin America, as well as China, India and Southeast Asian countries, have not only made outstanding progress in mining, but also made great progress in manufacturing. As far as every country is concerned, there is a trend that productivity is constantly lagging behind or expanding in underdeveloped areas. For example, the American economy has shifted to the "sunshine zone" in the south and west, Japan has developed the coastal areas of Hokkaido and the Sea of Japan, France has listed the western coastal areas and the central plateau as the focus of land consolidation, the southern economic center of West Germany, represented by Munich and Stuttgart, is taking shape, the development of the British North Sea oil field has promoted the economic development in northern Scotland, the Soviet Union has moved the productive forces eastward by vigorously developing the eastern region, the rise of heavy industrial zones in southern India, and the development of the Amazon River basin in northern Brazil. Furthermore, if we look at the countries and regions around the Pacific Ocean, from the rapid economic development of the States along the Pacific Ocean in the United States, Japan's leap to the second economic power in the capitalist world, and the eastward shift of Soviet productivity, to the great power displayed by the wave of reform and opening up in China, the rapid economic growth of some countries and regions in Southeast Asia, together with developed countries such as Canada and Australia with abundant resources and great potential, and developing countries in Latin America such as Mexico, all indicate the rapid economic rise around the Pacific Ocean and the new development of the world productivity distribution pattern.