Fortune Telling Collection - Free divination - Analysis on the present situation of land resources in Xinjiang

Analysis on the present situation of land resources in Xinjiang

By the end of 2005, the total land area of Xinjiang Uygur Autonomous Region was 65.438+66.49 million square kilometers (equivalent to 2.497 billion mu), accounting for about 65.438+0/6 of the total land area of the whole country. Agricultural land is 63.0607 million hectares (946 million mu), accounting for 37.88% of the total land area, including 4.0634 million hectares (60.9565438 mu) of cultivated land, accounting for 6.45% of the agricultural land area; The garden area is 354,300 hectares (5314500 mu), accounting for 0.56% of the agricultural land area; Woodland is 6,770,700 hectares (1.0 1.5605 million mu), accounting for1.74% of the agricultural land area; Grassland is 5 1 160700 hectares (7674 10500 mu), accounting for 81.13% of the agricultural land area; Other agricultural land is 7 1. 1.6 million hectares (1.0674 million mu), accounting for1.3% of the agricultural land area; The construction land is 6.5438+0.2207 million hectares (/kloc-0.8 million mu), accounting for 0.73%, of which 976.3 million hectares are residential and industrial land (6.5438+0.4644 million mu), accounting for 79.97% of the construction land area; The traffic land is 610.2 million hectares (910.8 million mu), accounting for 5.01%of the construction land area; Land for water conservancy facilities183,300 hectares (2,749,500 mu), accounting for1505,438+0% of the construction land area; Unused land 102208300 hectares (15.33 million mu), accounting for 6 1.39%. The utilization rate of land development is 38.6 1%. The per capita arable land is 0.20 hectares (3.03 mu).

Section 1 Spatial Distribution of Land Resources

The total area of the whole territory is1664,900 square kilometers; Among them, 39 1.850 hectares in northern Xinjiang; It accounts for 23.54% of the total area of the region. South Xinjiang/KLOC-0.063389 million hectares, accounting for 63.87% of the total land area. Dongjiang is 20,965,800 hectares, accounting for 12.59% of the total land area.

I. Agricultural land

Agricultural land is 63.0607 million hectares (946 million mu), accounting for 37.88% of the total land area. 32.3689 million hectares in northern Xinjiang, accounting for 51.3% of the total agricultural land area; South Xinjiang has 254 1.9 1 10,000 hectares, accounting for 40.3% of the total agricultural land area; Dongjiang has 5,272,700 hectares, accounting for 8.4% of the total agricultural land area, including:

(1) cultivated land

The total area is 4,063,400 hectares, accounting for 6.44% of the agricultural land area. North Xinjiang is 22910.8 million hectares, accounting for 56.4% of the cultivated land area; South Xinjiang1637,900 hectares, accounting for 40.31%of the cultivated land area; Dongjiang has 133700 hectares, accounting for 3.29% of the cultivated land area.

(2) Garden

The total area is 354,300 hectares, accounting for 0.56% of the agricultural land area. 43,500 hectares in northern Xinjiang, accounting for12.28% of the garden area; 275,300 hectares in southern Xinjiang, accounting for 77.70% of the garden area; Dongjiang River covers 35,500 hectares, accounting for 10.2% of the garden area.

(3) Woodland

The total area is 6,770,700 hectares, accounting for 10.74% of the agricultural land area. 24910.6 million hectares in northern Xinjiang, accounting for 36.8% of the forest land area; South Xinjiang has 3,686,800 hectares, accounting for 54.48% of the forest land area; Dongjiang covers an area of 590,400 hectares, accounting for 8.72% of the forest area.

(4) Grassland grazing

The total area is 5 1 160700 hectares, accounting for 8 1. 13% of the agricultural land area. There are 27.2683 million hectares in northern Xinjiang, accounting for 53.3% of the grassland area; There are 19420500 hectares in southern Xinjiang, accounting for 37.96% of the grassland area; Dongjiang River is 44710.9 million hectares, accounting for 8.74% of the grassland area.

Second, the construction land

The total area is 654.38+0.2207 hectares, accounting for 0.73% of the total land area. 480,000 hectares in northern Xinjiang, accounting for 39.32% of the total construction land area; 528,700 hectares in southern Xinjiang, accounting for 43.31%of the total construction land area; Dongjiang 21.2000 hectares, accounting for 17.38% of the total construction land area. These include:

(1) Industrial and mining land in residential area

The total area is 976,200 hectares, accounting for 79.97% of the construction land area. 409,300 hectares in northern Xinjiang, accounting for 41.93% of the industrial and mining land area of residential areas; South Xinjiang has 365,700 hectares, accounting for 37.46% of the industrial and mining land area in residential areas; Dongjiang River is 2010.2 million hectares, accounting for 20.6 1% of the industrial and mining land area in residential areas.

(2) Traffic land

The total area is 61.2000 hectares, accounting for 5.0 1% of the construction land area. 29,000 hectares in northern Xinjiang, accounting for 47.38% of the traffic land area; 23,700 hectares in southern Xinjiang, accounting for 38.73% of the traffic land area; Dongjiang River covers 8500 hectares, accounting for 13.89% of the traffic land area.

(3) Land for water conservancy facilities

The total area is 183300 hectares, accounting for 15.02% of the construction land area. North Xinjiang is 410.7 million hectares, accounting for 22.75% of the land area for water conservancy facilities; South Xinjiang 139300 hectares, accounting for 76% of the land area of water conservancy facilities; Dongjiang is 2300 hectares, accounting for 65438 0.25% of the land area of water conservancy facilities.

Third, idle land.

The total area is 102208300 hectares, accounting for 6 1.39% of the total land area. 6336 1 10,000 hectares in northern Xinjiang, accounting for 6.20% of the total area of unused land; South Xinjiang is 8039. 1 10000 hectares, accounting for 78.65% of the total unused land area; Dongjiang 1548.5438+0 10000 hectares, accounting for 15. 15% of the total unused land area. The spatial distribution of land resources in Xinjiang in 2005 is shown in tables 2- 1- 1 and 2- 1-2.

Table 2 Present situation of land use in Xinjiang in 2005

Table 2- 1-2 Composition of Land Use Status in Xinjiang

Section 2 Land Use Change

Based on the investigation of all kinds of land resources in the whole region during 1996 ~ 2005, the dynamic changes of land use during 1996 ~ 2000 and 200 1 ~ 2005 were analyzed.

From 1996 to 2000, the change of land use area, grassland and unused land decreased, while other land types increased. The total area of cultivated land in the whole region has increased from 65,438 3,985,700 hectares in196 to 465,438 0,640 hectares in 2000, with an increase of 65,438 0.783 hectares and a growth rate of 4.48%. The garden area increased from164,600 hectares in 1996 to192,200 hectares in 2000, with an increase of 27,600 hectares and an increase rate of 16.77%. The forestland area increased from 65,438+6,400,900 hectares in 1996 to 65,645,438+0,000 hectares in 2000, an increase of163,200 hectares, with a growth rate of 2.55%; The residential and industrial land increased from 65,438+868,000 hectares in 1996 to 886,800 hectares in 2000, with an increase of 1.89 million hectares and a growth rate of 2 1.8%.

From 200 1 to 2005, the most obvious change in land use was that the total cultivated land area in the whole region decreased from 200 1 to 4 16400 hectares year by year. By the end of 2005, the total cultivated land area in the whole region was 4,063,400 hectares, and the cultivated land decreased by 100600 hectares, with a reduction rate of 242%. Garden, woodland, residential area and industrial and mining land have increased steadily, with the garden area increasing from 200196800 hectares to 354300 hectares in 2005, an increase of 157500 hectares, with a growth rate of 80.03%. The forestland area increased from 6,567,200 hectares in 200 1 year to 6,770,700 hectares in 2005, an increase of 203,500 hectares, with an increase rate of 3.10%; Residential areas and industrial and mining land increased from 888,900 hectares in 200/kloc-0 to 976,300 hectares in 2005, an increase of 87,400 hectares, with a growth rate of 9.83%.

I. Agricultural land

(A) Analysis of the change trend of cultivated land area

1996 ~ 2005, the total area of cultivated land in the whole region was 3,985,700 hectares, expanding to 4,063,400 hectares. Among them, 168300 hectares was increased during the ninth five-year plan period; The decrease of 90,600 hectares during the Tenth Five-Year Plan period is mainly due to the ecological conversion of farmland and the adjustment of agricultural structure.

Figure 2-1-11996 ~ 2005 cultivated land change trend map in Xinjiang

Figure 2- 1-2 1996 ~ 2005 cultivated land change trend map in Xinjiang

From 1996 to 200 1, the cultivated land areas in southern, northern and eastern Xinjiang all showed an increasing trend, and decreased in 2002. In 2003, the cultivated land area in southern and northern Xinjiang decreased further, while the cultivated land area in eastern Xinjiang increased slowly. In 2005, the cultivated land area in Xinjiang increased completely.

The biggest feature of land use change in 2002 is the obvious acceleration of ecological returning farmland and the intensification of agricultural structure adjustment. According to the statistics of land change in Xinjiang, the total cultivated land area is 4 1 15900 hectares. According to the analysis of land use change in Xinjiang, the direction of cultivated land reduction is mainly in the following four aspects: the area of ecological returning farmland is 53 thousand hectares, and the agricultural structure adjustment occupies 36 thousand hectares. Construction occupies 3600 hectares of cultivated land, and natural disasters destroy cultivated land 1800 hectares. Ecological returning farmland and agricultural structure adjustment account for 6. 1% and 38.2% of the decrease of cultivated land in Xinjiang respectively. In 2002, Xinjiang reclaimed 47,500 hectares of cultivated land through land consolidation, and the supplementary cultivated land was 425,438+00,000 hectares more than the cultivated land occupied by construction and damaged by disasters. If we do not consider the occupation of cultivated land by agricultural structural adjustment and ecological returning farmland, we will basically achieve the balance of occupation and compensation of cultivated land.

In 2003, the cultivated land area in Xinjiang was 4,037,200 hectares. The changes of cultivated land are: increasing cultivated land by 39,400 hectares, increasing source consolidation by 30,600 hectares, developing 265,438 hectares+0,000 hectares, reclaiming 0,200 hectares, adjusting agricultural structure by 23,000 hectares and other 42,000 hectares. The whole region reduced cultivated land by 1 1.85438+0 million hectares. The reasons for the decrease are: 2400 hectares occupied by construction, 6 1900 hectares of ecological farmland, 53 1000 hectares of agricultural structure adjustment, 0 1000 hectares damaged by natural disasters and 0,600 hectares of others. Compared with 2002, the cultivated land in the whole region decreased by 78,700 hectares.

In 2004, the cultivated land area in Xinjiang was 4,025,500 hectares. The change of cultivated land is: increasing cultivated land by 22,200 hectares. 60,000 hectares of new source land were arranged, 850,000 hectares were developed, 80,000 hectares were reclaimed, 508,000 hectares of agricultural structure were adjusted, and 720,000 hectares were other. The whole region reduced 33,900 hectares of cultivated land. Reasons for the decrease: construction occupied 0. 1.9 million hectares, ecological returning farmland/kloc-0.1.7 million hectares, agricultural restructuring 1.8 1.00 million hectares, natural disasters damaged 0.6 million hectares and others 0.2/kloc. Compared with 2003, the total cultivated land area decreased by 1. 1.7 million hectares.

In 2005, the cultivated land area in Xinjiang was 4,063,400 hectares. The change of cultivated land is: increasing cultivated land by 60 1 10,000 hectares. The sources of increase are: land consolidation 0.0 1.3 million hectares, development/kloc-0.8 million hectares, reclamation 0.25 million hectares, agricultural restructuring/kloc-0.27 million hectares and other 29,000 hectares. The whole region reduced cultivated land by 22,200 hectares. Reasons for the decrease: 2,600 hectares were occupied by construction, 4,300 hectares were returned to farmland, 65,438+4,200 hectares were adjusted in agricultural structure, 0 1800 hectares were damaged by natural disasters, and 0,900 hectares were other. Compared with 2004, the cultivated land in the whole region increased by 37,900 hectares.

(2) Analysis of the change trend of garden area.

From 1996 to 2005, the garden area increased from 164600 hectares to 354300 hectares, an increase of 189700 hectares, and the growth rate was 1 15%, which was a huge increase.

Figure 2- 1-3 1996 ~ 2005 Landscape Changes in Xinjiang

Figure 2- 1-4 1996 ~ 2005 Landscape Change Trend in Xinjiang

From 1996 to 200 1, the garden areas in southern Xinjiang, northern Xinjiang and eastern Xinjiang all showed an increasing trend, with the growth rates of 18%, 25% and 19.5% respectively, with a relatively large growth rate in the whole region. From 200 1 to 2005, the garden area in southern Xinjiang, northern Xinjiang and eastern Xinjiang showed a rapid growth trend, especially in southern Xinjiang, with the growth rates of 94. 16%, 17.64% and 27.85% respectively.

The regional particularity of light, heat and other resources in Xinjiang is conducive to the development of forest and fruit industry with local characteristics. In recent years, due to market demand, the garden area in Xinjiang has shown a great growth trend. The abundant light and heat resources in southern Xinjiang are conducive to the development of horticultural production and vigorously develop the characteristic high-quality forest and fruit industrial belt around Tarim Basin, thus promoting the garden area in southern Xinjiang to increase substantially.

(3) Analysis of the change trend of forestland area

From 1996 to 2005, the forest land grew steadily, and the area expanded from 6.4009 million hectares to 6.7707 million hectares, an increase of about 370,000 hectares, with a growth rate of 5.77%. From 200 1, the increase is very large.

Fig. 2- 1-5 1996 ~ 2005 Change Trend of Woodland in Xinjiang

(D) Analysis of the change trend of grassland area

From 1996 to 2005, the grassland area decreased from 5 1596000 hectares to 502 15800 hectares, a decrease of 1380200 hectares. The area of artificial grassland increased from 94,700 hectares to 246,200 hectares, increasing by 15 150 hectares, with a growth rate of 160%.

Second, the main construction land changes

Total construction land increased from1087,000 hectares in 2006 to1220,700 hectares in 2005. Among them, residential areas and industrial and mining land increased by 1.89 million hectares during the Ninth Five-Year Plan period and by 87,500 hectares during the Tenth Five-Year Plan period; Transportation land increased by 1.4 1 10,000 hectares; Land for water conservancy facilities increased by1.1.4000 hectares.

Fig. 2- 1-6 1996 ~ 2005 grassland changes in Xinjiang

Figure 2- 1-7 1996 ~ 2005 Change Trend of Artificial Grassland in Xinjiang

Figure 2- 1-8 1996 ~ 2005 Change Trend of Construction Land in Xinjiang

Through the investigation of residential and industrial land area in the whole region from 1996 to 2005, the changing trend of residential and industrial land area in the whole region is obtained (see Figure 2- 1-9).

Figure 2- 1-9 1996 ~ 2005 residential and industrial land change trend map in Xinjiang

Figure 2-1-101996 ~ 2005: the change trend of residential areas and industrial and mining land in Xinjiang.

From 1996 to 200 1, the residential areas and industrial and mining land areas in southern Xinjiang, northern Xinjiang and eastern Xinjiang all showed an increasing trend, with growth rates of 2.97%, 2.93% and 0.43% respectively. From 200 1 to 2004, the area of residential areas and industrial and mining land in southern Xinjiang, northern Xinjiang and eastern Xinjiang continued to increase, especially in northern Xinjiang, with growth rates of 3.95%, 15.88% and 6.28% respectively.

In 2005, the total area of residential land and industrial and mining land in the whole region was 976,300 hectares, of which 39,400 hectares were urban land, accounting for 4.04% of the total area; 46,200 hectares, accounting for 4.73%; The village land is 479,600 hectares, accounting for 49 12%.

The scale of urban land use in the autonomous region has been expanding. Compared with 1996, the urban land in 2005 was 39,400 hectares, an increase over 1 1.6 1%. The scale of urban land use is also expanding. The scale of residential land shows a sustained and steady upward trend.

Figure 2-1-11kloc-0/996 ~ 2005 urban land use change in Xinjiang

Figure 2-1-121996 ~ 2005 land use change in Xinjiang.

Figure 2-1-131996 ~ 2005 Rural Residential Land Change

Section 3 Characteristics of Land Resources

1. Oasis characteristics of land resources development and utilization

Xinjiang has a vast land area of 6.5438+0.6649 million square kilometers, but the main space of human activities is concentrated in oases. Xinjiang oasis area 125900 square kilometers, accounting for 7.56% of the total land area in Xinjiang. Among them, the artificial oasis covers an area of 99,800 square kilometers, accounting for 5.99% of the total land area in Xinjiang, and the natural oasis covers an area of 2,665.438 million square kilometers, accounting for 1.57% of the total land area in Xinjiang.

Artificial oasis includes cultivated land, garden, plantation, artificial grassland, industrial and mining land, traffic land and water conservancy facilities. Artificial oasis reflects the degree of land resources development and utilization in Xinjiang, and almost all social and economic activities in Xinjiang are concentrated on artificial oasis, which has become a unique land development and utilization model in Xinjiang.

Natural oases include plain valley forests, plain shrubs, plain meadows, rivers, lakes, open-pit mines and other land types. The condition of natural oasis reflects the protection degree and quality of land resources utilization environment in Xinjiang, which is closely related to artificial oasis. Most artificial oases are evolved from the development and utilization of natural oases, and there are complex constraints between artificial oases and natural oases.

The quality and development scale of oasis are ultimately restricted by water supply. The oasis utilization form of land use in Xinjiang is the biggest feature of land resources utilization in Xinjiang. Correctly handling the relationship among natural oasis, artificial oasis and desert land and reasonably determining the scale of artificial oasis are problems that must be considered in the development and utilization of land resources in Xinjiang.

Second, the characteristics of developing characteristic agriculture

Abundant light and heat resources and relatively stable ecological conditions of oasis irrigation agriculture make Xinjiang have the objective conditions for developing characteristic agriculture. First of all, the irrigation of agricultural water has a certain guarantee, and it can be irrigated in a timely and appropriate amount according to the needs of crop growth, which lays a reliable foundation for crops to make full use of light and heat resources and soil nutrients and achieve high quality and high yield. Meanwhile, water resources are relatively stable. The interannual variation coefficient of total surface runoff in Xinjiang is only 0. 13, and the relative variation rate is 38%. In warm years, frozen snow in high mountains melts and supplies more, while precipitation in middle and low mountains supplies less; In cold and wet years, there are more precipitation supplies in middle and low mountains and less snow supplies in high mountains. This water supply law ensures that water resources can play a complementary role in warm years or cold and wet years, and the water source remains basically stable. Secondly, abundant light and heat resources are an important guarantee for the development of characteristic agriculture in Xinjiang. Due to drought and lack of rain, sunny weather, low air humidity and high atmospheric transparency, solar radiation in Xinjiang reaches 1.30 ~ 1.50km/cm2 a year, second only to the Qinghai-Tibet Plateau. The sunshine time is long, and the annual sunshine hours are hundreds of hours more than those in the same latitude areas in China. The diurnal temperature range is large, and the effective cooperation of irrigation can reach the same period of water and heat, with good photosynthesis and more dry matter accumulation. Therefore, Xinjiang has a good foundation for developing characteristic agriculture. Such as high-quality wheat, corn, rape, oil sunflower, safflower, peanut, high-quality cotton, beet, flax, high-quality fruits, vegetables and fruits. Therefore, in the development and utilization of land resources, we should fully grasp the characteristics of land resources in Xinjiang and develop characteristic agriculture.

Third, it has the characteristics of fragile ecological environment.

Xinjiang is located in the hinterland of Eurasia, with an average annual precipitation of 65,438 0.50 mm, accounting for only 4% of the country. Forest and grassland vegetation is mainly distributed in mountainous areas, and the vast plains are desert vegetation, with easy desertification and fragile ecological environment. The annual gale frequency in plain area is as high as 10 ~ 20 days, and the sandstorm frequency accounts for more than 15% of the annual gale frequency. At the same time, there are abundant sand sources, and strong winds and sand raising provide dynamic conditions for land desertification, which is quite serious. Secondly, land salinization is widespread in Xinjiang. Due to drought and lack of rain, soil leaching is weak; Due to excessive irrigation and serious water leakage in the canal system, the groundwater level rises, and soil salinization is serious under the strong evaporation. Thirdly, in the deep inland of Xinjiang, all rivers in Xinjiang belong to inland rivers except Irtysh River, and toxic substances dissolved along the rivers can only gather in the basin, which leads to low self-purification ability of land resources and easy accumulation of toxic substances. Therefore, the fragile ecological environment must be fully considered when developing and utilizing land resources in Xinjiang.

Four, the development and utilization of land resources has obvious watershed characteristics.

The development and utilization of land resources in Xinjiang is based on river basins. Xinjiang mainly relies on precipitation in mountainous areas, and rivers flow to basins. There is little precipitation in the plain, and oasis, agriculture and ecology all need irrigation. Due to the restriction of irrigation conditions of water resources, the development and utilization of land resources are distributed in river basins. Humans first developed and utilized land from the lower reaches of the river delta. In ancient times, due to backward production tools and low productivity, most of them developed in the downstream areas with flat terrain, developed water network and easy water diversion. For example, ancient oases such as Niya and Loulan, buried deep in the desert of Tarim Basin, were developed by chasing aquatic plants. With the improvement of people's productivity and the progress of water conservancy technology, land development and utilization are gradually carried out in the middle and upper reaches by building dams, repairing canals and reservoirs. Therefore, the problem of rational distribution of water resources in the whole basin has emerged. Due to the excessive diversion of water from the upstream land development and utilization, the downstream reaches are cut off, the rivers become shorter and the lakes dry up. For example, the lower reaches of Tarim River have been cut off for many years, Lop Nur has dried up, and Ebinur Lake has shrunk, indicating that land development and utilization have not taken into account the characteristics of the basin. According to the basin characteristics of land use in Xinjiang, the unified management of land development and utilization first needs to manage water resources in accordance with the basin distribution. Therefore, the development and utilization of land in Xinjiang needs a unified water resources management policy and the coordination of land resources development and utilization.

Section 4 Xinjiang Oasis Area and Distribution

First, the concept and classification of Xinjiang oasis

(A) the concept and classification of oasis

1. The concept of oasis

Oasis can be defined as an area with stable water source, abundant light and heat resources and good soil quality, which can meet the normal reproduction of mesophytes and is suitable for human beings to continue to engage in social and economic activities in the arid and desert geographical environment.

2. The connotation of oasis

The so-called "oasis" must include the following connotations:

(1) Oasis is located in arid desert area.

(2) Stable water source is the basic condition or leading factor for the existence of oasis.

(3) Green vegetation is the basic feature of oasis. Lush vegetation is the main landscape of natural oasis, and artificial ecology is the main landscape of artificial oasis.

(4) Oasis should constitute a unique eco-geographical system.

(B) the classification of oasis

The classification of oasis types is helpful for human beings to deeply study the formation and evolution of oases, and it is also convenient for human beings to adopt corresponding development and utilization methods and appropriate construction and protection measures according to different oasis types.

The classification of oasis types should follow the principles of historical evolution, functionalization and practical principles.

In academic circles, there have been many views on the division of oasis, and there is also a lot of knowledge. Because of the different classification angles, multi-level division can be adopted. For example, according to the intervention degree of human activities, oases can be divided into natural oases, artificial oases and semi-artificial oases (or quasi-oases). According to the time scale of formation, it can be divided into ancient oasis, old oasis, new-old oasis and new oasis. According to the spatial scale, it can be divided into super-large oasis, large oasis, medium oasis and small oasis; Or it can be divided into oasis groups (composed of many oases with the same geographical unit), oases (referring to complete oases of considerable scale) and oases (referring to scattered oases with smaller scale). According to its leading role in social economy, it can be divided into agricultural oasis, urban oasis, industrial and mining oasis and animal husbandry oasis.

Limited by data and work basis, natural oases are divided into natural grassland oases and natural wetland oases according to the principle of rough but not refined; Artificial oases can be divided into towns, agriculture, forests, animal husbandry oases and industrial and mining oases. See table 2- 1-3 for details. Second, the area, structure and distribution of Xinjiang oasis

Table 2- 1-3 Classification of Oasis Types in Xinjiang

(A) the scope and area of Xinjiang Oasis

According to the concept of oasis and its basic conditions of existence, oasis is formed in desert areas. Therefore, when dividing oasis, it is necessary to divide desert area and non-desert area (semi-humid and humid area) to confirm the scope of oasis in desert area. See table 2- 1-4 for details.

Table 2- 1-4 Xinjiang desert area and regional distribution unit: 10,000 hectares

1. Division of desert areas

Desert area is characterized by scarce precipitation, arid climate, abundant light and heat resources, less surface runoff, sparse or no vegetation coverage, and desert and Gobi are widely distributed, showing desert landscape.

2. The division of oasis scope

Oasis is a special geographical landscape formed in desert environment and has its own characteristics. Oasis can be divided according to the following signs:

(1) signs for dividing oases:

(1) Water is the basic condition for the existence of oasis. Any area with abundant water sources (groundwater, rivers, lakes, etc.). ) Desert areas that can meet the reproductive needs of mesophytes and hygrophytes belong to oasis.

(2) Irrigation agriculture is an important symbol of the existence of oasis. Irrigation channels or pipelines control the oasis, and the irrigation surplus water can reach and satisfy the growth of mesophytes.

(3) The distribution of trees, shrubs and meadow vegetation around rivers, lakes and swamps in desert areas.

④ Wasteland (such as small sandy land, saline-alkali land, bare land, grassland, etc.). ) and abandoned farmland, waste canals, roads, residential sites, historical sites and other land within the oasis with less than 100 hectares can all be included in the oasis.

⑤ According to the types of land use, oasis land cover includes cultivated land, garden, pasture (artificial grassland and meadow grassland), woodland (plantation, valley forest), industrial and mining land in residential areas (townships, towns and villages), channels, reservoirs, lakes, pits and ponds, various roads and cemeteries.

(2) Methods and steps of oasis division:

① The 1975 Landsat MSS (resolution 79m), 2000 Landsat TM (resolution 30m) and 2005 CBERS (resolution 20m) between China and Pakistan (in which Kashgar, Yili and Tacheng are French Spot satellites with resolution 10m) are accurately registered in Xinjiang, and converted into Albert equal area cone projection.

(2) According to the oasis division sign and the principle of dividing natural oasis and artificial oasis, the oasis interpretation sign on the remote sensing image is established, and the remote sensing image of the same area is interpreted independently by two interpreters. If the interpretation is consistent, the interpretation type can be determined, and the interpretation type can only be determined after the third party reinterprets it.

(3) On the basis of checking the administrative boundaries of counties in Xinjiang, according to the oasis maps, calculate the oasis areas of counties (cities) and make statistics to prefectures (cities) and autonomous regions step by step.

3. Calculation results of oasis area

After this investigation, the total oasis area in Xinjiang was 1.975, in 2000 and 2005, respectively, 1.765, 438+0.99 hectares, 1.536 million hectares and 1.259 million hectares, respectively, accounting for the territory of Xinjiang. Among them, the artificial oases are 6,002,300 hectares, 8,620 862. 1.44 million hectares and 9,980,600 hectares respectively, and the natural oases are 4,765,438+0.75 million hectares, 2,965,438+0.47 million hectares and 2,665,438+0.23 million hectares respectively. See table 2- 1-5 for details.

Table 2- 1-5 Xinjiang Oasis Area in Different Periods Table Unit: 10,000 hectares

4. Changes of oasis area in Xinjiang.

Oasis area is historical and dynamic data. In the past 50 years, the area of artificial oasis in Xinjiang has been expanding continuously. By 2005, the area had reached 9.9806 million hectares, accounting for 6.04% of the total land area in Xinjiang. Compared with the early days of liberation, the area of artificial oasis in Xinjiang in 1949 was about 2.25 million hectares, which increased to 4.44 times in 56 years. It can be seen that the expansion speed of modern Xinjiang artificial oasis is still very fast. The rapid expansion of artificial oasis area mainly depends on the large-scale development of the north and south of Tianshan Mountain, especially the development of Junggar Basin in northern Xinjiang. Before 1980s, the area of artificial oasis in Xinjiang was the largest in southern Xinjiang. At present, after more than 50 years of development, especially in recent 30 years, the area of artificial oasis in northern Xinjiang has surpassed that in southern Xinjiang, accounting for 49.92% of the total area of artificial oasis in Xinjiang, while southern Xinjiang has retired to the second place, accounting for 46.04% and eastern Xinjiang only accounts for 4.04%.

The natural oasis in Xinjiang covers an area of 2,665,438 0.23 million hectares, accounting for 65,438 0.58% of the total land area in Xinjiang and 20.74% of the oasis area. Natural oases are mainly distributed in southern Xinjiang, with197.110000 hectares, accounting for 75.45% of the total number of natural oases in Xinjiang. There are only 628,000 hectares of natural oases in northern Xinjiang, accounting for 24.04% of the total area of natural oases in Xinjiang, mainly distributed in Altay, Tacheng and Yili. The natural oasis area in Dongjiang is 1.3 1.0000 hectares, accounting for only 0.50% of the natural oasis area in Xinjiang.

(1) The regional distribution of Xinjiang oasis.

See table 2- 1-6 for the regional distribution of Xinjiang oasis.

As can be seen from the table:

Table 2- 1-6 Xinjiang Oasis Area and Specific Gravity Unit: 10,000 hectares

—— In terms of regional distribution of oases, southern Xinjiang is more than northern Xinjiang, while in terms of oasis coverage rate (i.e. the proportion of total oasis area), northern Xinjiang is higher than southern Xinjiang.

Judging from the situation of natural oases, the area with the largest natural oasis area and the highest coverage rate is in southern Xinjiang.

Judging from the situation of artificial oasis, the area of northern Xinjiang is slightly larger than that of southern Xinjiang, and the coverage rate of artificial oasis is also higher in northern Xinjiang than in southern Xinjiang.

(2) The ranking of oasis 10 top counties (cities).

There are great differences in oasis area (scale) among counties (cities) in Xinjiang. As far as oasis is concerned, bachu county, with the largest area, is 610.02 million hectares, which is 277 times that of Wuqia County with the least oasis area. Among the natural oases, Ruoqiang County is the largest, reaching 352,600 hectares. The counties and cities with the largest artificial oasis area are Shawan County, Aksu City, bachu county, Wusu City, Manas, Qitai County, Hutubi County, emin county, shache county and Awati. Shawan County, with the largest artificial oasis area of 443,300 hectares, is 2 1 times of Wuqia County, with the smallest area of 0.2 1 10,000 hectares. See table 2- 1-7 for the ranking of counties (cities) before Xinjiang oasis area (scale).

Table 2- 1-7 Top Oasis Area in Xinjiang 10 County (city) area: 10,000 hectares.