Analysis of current situation of land resources in Xinjiang

At the end of 2005, the total land area of ??the Xinjiang Uygur Autonomous Region was 1.6649 million square kilometers (equivalent to 2.497 billion acres), accounting for approximately 1/6 of the country's total land area. There are 63.0607 million hectares (946 million acres) of agricultural land, accounting for 37.88% of the total land area. Among them, 4.0634 million hectares (60.951 million acres) of cultivated land, accounting for 6.45% of the agricultural land area; 354,300 hectares (5.3145 million acres) of garden land, accounting for 0.56% of the agricultural land area; forest land 6.7707 million hectares (101.5605 million acres), accounting for 10.74% of the agricultural land area; pastureland 51.1607 million hectares (767.4105 million acres), accounting for 81.13% of the agricultural land area; other agricultural land 711,600 hectares (10.674 million acres), accounting for 1.13% of the agricultural land area; construction land is 1.2207 million hectares (18 million acres), accounting for 0.73%, of which 976,300 hectares (14.6445 million acres) are residential and industrial and mining land, accounting for 10% of the construction land area 79.97%; 61,200 hectares (918,000 acres) of transportation land, accounting for 5.01% of the construction land area; 183,300 hectares (2.7495 million acres) of water conservancy facility land, accounting for 15.01% of the construction land area; 102.2083 million hectares (153.33 million acres) of unused land billion acres), accounting for 61.39%. The land development and utilization rate is 38.61%. The per capita cultivated land is 0.20 hectares (3.03 acres).

Section 1 Spatial Distribution of Land Resources

The total land area of ??Xinjiang is 1.6649 million square kilometers, of which 39.185 million hectares are in northern Xinjiang, accounting for approximately 23.54% of the total land area of ??Xinjiang; Southern Xinjiang has 106.3389 million hectares, accounting for approximately 63.87% of the total land area of ??Xinjiang; Eastern Xinjiang has 20.9658 million hectares, accounting for approximately 12.59% of the total land area of ??Xinjiang.

1. Agricultural land

Agricultural land is 63.0607 million hectares (946 million acres), accounting for 37.88% of the total land area. Northern Xinjiang has 32.3689 million hectares, accounting for 51.3% of the total agricultural land area; Southern Xinjiang has 25.4191 million hectares, accounting for 40.3% of the total agricultural land area; Eastern Xinjiang has 5.2727 million hectares, accounting for 8.4% of the total agricultural land area, including:

(1) Cultivated land

The total area is 4.0634 million hectares, accounting for 6.44% of the agricultural land area. Northern Xinjiang has 2.2918 million hectares, accounting for 56.4% of the cultivated land area; Southern Xinjiang has 1.6379 million hectares, accounting for 40.31% of the cultivated land area; Eastern Xinjiang has 133,700 hectares, accounting for 3.29% of the cultivated land area.

(2) Garden land

The total area is 354,300 hectares, accounting for 0.56% of the agricultural land area. The northern Xinjiang has 43,500 hectares, accounting for 12.28% of the garden area; the southern Xinjiang has 275,300 hectares, accounting for 77.70% of the garden area; the eastern Xinjiang has 35,500 hectares, accounting for 10.2% of the garden area.

(3) Forest land

The total area is 6.7707 million hectares, accounting for 10.74% of the agricultural land area. Northern Xinjiang has 2.4916 million hectares, accounting for 36.8% of the forest area; Southern Xinjiang has 3.6868 million hectares, accounting for 54.48% of the forest area; Eastern Xinjiang has 590,400 hectares, accounting for 8.72% of the forest area.

(4) Pastureland

The total area is 51.1607 million hectares, accounting for 81.13% of the agricultural land area. Northern Xinjiang has 27.2683 million hectares, accounting for 53.3% of the pasture area; Southern Xinjiang has 19.4205 million hectares, accounting for 37.96% of the pasture area; Eastern Xinjiang has 4.4719 million hectares, accounting for 8.74% of the pasture area.

2. Construction land

The total area is 1.2207 million hectares, accounting for 0.73% of the total land area. Northern Xinjiang has 480,000 hectares, accounting for 39.32% of the total construction land area; Southern Xinjiang has 528,700 hectares, accounting for 43.31% of the total construction land area; Eastern Xinjiang has 212,000 hectares, accounting for 17.38% of the total construction land area. Among them:

(1) Industrial and mining land in residential areas

The total area is 976,200 hectares, accounting for 79.97% of the construction land area. The northern Xinjiang has 409,300 hectares, accounting for 41.93% of the industrial and mining land area in residential areas; the southern Xinjiang has 365,700 hectares, accounting for 37.46% of the residential industrial and mining land area; the eastern Xinjiang has 201,200 hectares, accounting for 20.61% of the residential industrial and mining land area.

(2) Transportation land

The total area is 61,200 hectares, accounting for 5.01% of the construction land area. There are 29,000 hectares in northern Xinjiang, accounting for 47.38% of the transportation land area; 23,700 hectares in southern Xinjiang, accounting for 38.73% of the transportation land area; and 8,500 hectares in eastern Xinjiang, accounting for 13.89% of the transportation land area.

(3) Land for water conservancy facilities

The total area is 183,300 hectares, accounting for 15.02% of the construction land area.

There are 41,700 hectares in northern Xinjiang, accounting for 22.75% of the land area for water conservancy facilities; 139,300 hectares in southern Xinjiang, accounting for 76% of the land area for water conservancy facilities; and 2,300 hectares in eastern Xinjiang, accounting for 1.25% of the land area for water conservancy facilities.

3. Unused land

The total area is 102.2083 million hectares, accounting for 61.39% of the total land area. Northern Xinjiang has 6.3361 million hectares, accounting for 6.20% of the total unused land area; Southern Xinjiang has 80.3911 million hectares, accounting for 78.65% of the total unused land area; Eastern Xinjiang has 15.4811 million hectares, accounting for 15.15% of the total unused land area. The spatial distribution of land resources in Xinjiang in 2005 is detailed in Table 2-1-1 and Table 2-1-2.

Table 2-1-1 Current status of land use in Xinjiang in 2005

Table 2-1-2 Current status of land use in Xinjiang

Section 2 Land Use Changes

Through the investigation of various land use areas of land resources in the region from 1996 to 2005, the dynamic changes in land use in the two periods of 1996 to 2000 and 2001 to 2005 were analyzed.

Changes in land use area from 1996 to 2000, pasture and unused land decreased, while other land types increased. The total area of ??cultivated land in the region expanded year by year from 3.9857 million hectares in 1996 to 4.164 million hectares in 2000, an increase of 178,300 hectares, an increase of 4.48%; the area of ??garden land increased from 164,600 hectares in 1996 to 2,000 hectares. The area of ??forest land expanded from 6.4009 million hectares in 1996 to 6.5641 million hectares in 2000, with an increase of 163,200 hectares of forest land, an increase of 2.55%; residents Residential, industrial and mining land increased from 868,000 hectares in 1996 to 886,800 hectares in 2000, with an increase of 18,900 hectares of residential, industrial and mining land, an increase of 2.18%.

From 2001 to 2005, the most obvious change in land use was that the total area of ??cultivated land in the region decreased year by year from 4.164 million hectares in 2001. By the end of 2005, the total area of ??cultivated land in the region was 4.0634 million hectares, with a decrease of 100,600 hectares. hectares, a decrease of 2.42%. The garden land, forest land, residential areas and industrial and mining land have grown steadily. Among them, the garden land area has increased from 196,800 hectares in 2001 to 354,300 hectares in 2005, an increase of 157,500 hectares, an increase of 80.03%, a huge increase; the forest land area has increased from 196,800 hectares in 2001 to 354,300 hectares in 2005. 6.5672 million hectares expanded to 6.7707 million hectares in 2005, with an increase of 203,500 hectares of forest land, an increase of 3.10%; residential and industrial and mining land increased from 888,900 hectares in 2001 to 976,300 hectares in 2005, an increase of 87,400 hectares. The increase was 9.83%, which was a relatively large increase.

1. Agricultural land

(1) Analysis of changing trends in cultivated land area

From 1996 to 2005, the total area of ??cultivated land in the region expanded from 3.9857 million hectares to 4.0634 million hectares hectares. Among them, there was an increase of 168,300 hectares during the "Ninth Five-Year Plan" period; a decrease of 90,600 hectares during the "Tenth Five-Year Plan" period, mainly due to the ecological return of farmland and the adjustment of agricultural structure.

Figure 2-1-1 The change trend of cultivated land in Xinjiang from 1996 to 2005

Figure 2-1-2 The change trend of cultivated land in various regions of Xinjiang from 1996 to 2005

From 1996 to 2001, the area of ??cultivated land in southern, northern, and eastern Xinjiang showed an increasing trend, and then declined in 2002. In 2003, the area of ??cultivated land in southern and northern Xinjiang further decreased, and in eastern Xinjiang, there was a slow growth. In 2005, the area of ??cultivated land in Xinjiang The area of ??cultivated land has increased.

The biggest feature of land use changes in 2002 is that the ecological return of farmland has accelerated significantly, and agricultural structural adjustment has intensified. According to statistics on land change data in Xinjiang, the total area of ??cultivated land was 4.1159 million hectares. According to land use changes in Xinjiang Situation analysis shows that the reduction of cultivated land is mainly in the following four aspects: 53,000 hectares of ecologically converted farmland, 36,000 hectares of cultivated land occupied by agricultural structural adjustment, 3,600 hectares of cultivated land occupied by construction, 1,800 hectares of cultivated land destroyed by natural disasters, 0.18 million hectares of cultivated land destroyed by ecological disasters and agricultural structural adjustment They accounted for 6.1% and 38.2% respectively of the reduced cultivated land in Xinjiang. In 2002, Xinjiang added 47,500 hectares of cultivated land through land consolidation, reclamation and development, and the replenished cultivated land was 42,100 hectares more than the cultivated land occupied by construction and destroyed by disasters. If the adjustment of agricultural structure and the occupation of cultivated land such as ecological return of farmland are not considered, a balance between occupation and compensation of cultivated land will basically be achieved.

In 2003, the cultivated land area in Xinjiang was 4.0372 million hectares. The changes in cultivated land are: 39,400 hectares of cultivated land increased, 30,600 hectares of additional source land consolidation, 2,100 hectares of development, 0,200 hectares of reclamation, 2,300 hectares of agricultural structure adjustment, and 4,200 hectares of others. The area's cultivated land decreased by 118,100 hectares.

The reasons for the decrease are: construction occupation of 2,400 hectares, ecological conversion of 61,900 hectares, agricultural structural adjustment of 53,100 hectares, natural disaster damage of 0,100 hectares, and other 0,600 hectares. Compared with 2002, the region's cultivated land decreased by 78,700 hectares net.

In 2004, the cultivated land area in Xinjiang was 4.0255 million hectares. The changes in cultivated land are as follows: an increase of 22,200 hectares of cultivated land. The additional sources of land consolidation include 0.6 million hectares, development of 0.85 million hectares, reclamation of 0.8 million hectares, agricultural structure adjustment of 0.508 million hectares, and others of 0.72 million hectares. The region's cultivated land decreased by 33,900 hectares. Reasons for the decrease: 1,900 hectares were occupied for construction, 11,700 hectares were abandoned for ecological purposes, 18,100 hectares were adjusted for agricultural structure, 0,060 hectares were damaged by natural disasters, and 2,100 hectares were damaged by others. Compared with 2003, the region's cultivated land decreased by 11,700 hectares net.

In 2005, the cultivated land area in Xinjiang was 4.0634 million hectares. The changes in cultivated land are as follows: an increase of 60,100 hectares of cultivated land. The sources of increase are: land consolidation of 0.13 million hectares, development of 18.000 hectares, reclamation of 0.25 million hectares, agricultural structure adjustment of 12.7 thousand hectares, and other 29.000 hectares. The region’s cultivated land decreased by 22,200 hectares. Reasons for the decrease: 2,600 hectares were occupied for construction, 4,300 hectares were abandoned for ecological purposes, 14,200 hectares were adjusted for agricultural structure, 0,180 hectares were damaged by natural disasters, and 0,900 hectares were damaged by other areas. Compared with 2004, the region's cultivated land increased by 37,900 hectares net.

(2) Analysis of changing trend of garden area

From 1996 to 2005, the garden area increased from 164,600 hectares to 354,300 hectares, an increase of 189,700 hectares, an increase of 115%. The increase is huge.

Figure 2-1-3 The change trend of gardens in Xinjiang from 1996 to 2005

Figure 2-1-4 The change trend of gardens in Xinjiang from 1996 to 2005

From 1996 to 2001, the area of ??gardens in South, North and East Xinjiang all showed an increasing trend, with growth rates of 18%, 25% and 19.5% respectively. The growth rate in the whole region was relatively large. From 2001 to 2005, the area of ??gardens in southern, northern, and eastern Xinjiang all showed a rapid growth trend, especially in southern Xinjiang, which grew the fastest, with growth rates of 94.16%, 17.64%, and 27.85% respectively.

The regional particularity of Xinjiang’s light, heat and other resources is conducive to the development of the forest and fruit industry with local characteristics. In recent years, due to market demand, Xinjiang's garden area has shown a significant growth trend. In addition, the rich light and heat resources in southern Xinjiang are conducive to the development of horticultural production, and vigorous development of the characteristic high-quality forest and fruit industry belt around the Tarim Basin has led to the expansion of southern Xinjiang's garden area. magnitude growth.

(3) Analysis of forestland area change trends

From 1996 to 2005, forestland increased steadily, with the area expanding from 6.4009 million hectares to 6.7707 million hectares, an increase of approximately 370,000 hectares. is 5.77%. It has increased significantly since 2001.

Figure 2-1-5 Change trend of forest land in Xinjiang from 1996 to 2005

(4) Analysis of change trend of pasture area

From 1996 to 2005, grassland The area decreased from 51.596 million hectares to 50.2158 million hectares, a decrease of 1.3802 million hectares. However, the area of ??artificial grassland increased from 94,700 hectares to 246,200 hectares, an increase of 151,500 hectares, an increase of 160%.

2. Changes in main construction land

The total amount of construction land increased from 1.087 million hectares in 1996 to 1.2207 million hectares in 2005. Among them, residential and industrial and mining land increased by 18,900 hectares during the Ninth Five-Year Plan and 87,500 hectares during the Tenth Five-Year Plan; transportation land increased by 14,100 hectares; water conservancy facility land increased by 11,400 hectares.

Figure 2-1-6 Change trend of pasture grassland in Xinjiang from 1996 to 2005

Figure 2-1-7 Change trend of artificial grassland in Xinjiang from 1996 to 2005

Figure 2-1-8 Change trend of construction land in Xinjiang from 1996 to 2005

Through the survey of the area of ??residential land and industrial and mining land in the whole region from 1996 to 2005, the changes in the area of ??residential land and industrial and mining land in the whole region were obtained trend (see Figure 2-1-9).

Figure 2-1-9 Change trends of residential areas and industrial and mining land in Xinjiang from 1996 to 2005

Figure 2-1-10 Residential areas and industrial and mining land in Xinjiang from 1996 to 2005 Change trend chart

From 1996 to 2001, the area of ??residential areas and industrial and mining land in southern, northern, and eastern Xinjiang all showed an increasing trend, with growth rates of 2.97%, 2.93%, and 0.43% respectively. From 2001 to 2004, the area of ??residential areas and industrial and mining land in southern, northern and eastern Xinjiang continued to show a growth trend, especially in northern Xinjiang, which grew the fastest, with growth rates of 3.95%, 15.88% and 6.28% respectively.

In 2005, the total area of ??residential, industrial and mining land in the region was 976,300 hectares, of which 39,400 hectares were urban land, accounting for 4.04% of the total area; 46,200 hectares were organized town land, accounting for 4.73%; village land was 479,600 hectares, accounting for 49.12%.

The scale of urban land in the autonomous region has been expanding. Compared with 1996, the urban land in the region in 2005 was 39,400 hectares, an increase of 11.61% over 1996. The scale of land used in organized towns is also showing an expanding trend. The size of land used in residential areas has shown a continuous and steady upward trend.

Figure 2-1-11 Changes in urban land use in Xinjiang from 1996 to 2005

Figure 2-1-12 Changes in land use in organized towns in Xinjiang from 1996 to 2005

Figure 2-1-13 Changes in land use in rural residential areas from 1996 to 2005

Section 3 Characteristics of land resources

1. Oasis characteristics of land resource development and utilization

Xinjiang has a land area of ??1.6649 million square kilometers, which is vast, but the main space for human activities is concentrated in oases. Xinjiang’s oasis area is 125,900 square kilometers, accounting for 7.56% of Xinjiang’s land area. Among them, artificial oasis area is 99,800 square kilometers, accounting for 5.99% of Xinjiang’s land area, and natural oasis area is 26,100 square kilometers. It accounts for 1.57% of the total land area of ??Xinjiang.

Artificial oasis includes cultivated land, garden land, artificial forest land, artificial grassland, industrial and mining land, transportation land, water conservancy facilities and other land. Artificial oases reflect the extent of land resource development and utilization in Xinjiang. Almost all social and economic activities in Xinjiang are concentrated on artificial oases, and artificial oases have become a unique model of land development and utilization in Xinjiang.

Natural oases include plain valley forests, plain shrubs, plain meadows, rivers, lakes, mines and other land types. The condition of natural oases reflects the degree of environmental protection and quality of land resource utilization in Xinjiang, and is closely related to artificial oases. Most artificial oases evolved from the development and utilization of natural oases. 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 resource utilization in Xinjiang. Correctly handling the relationship between natural oases, artificial oases and desert land, and reasonably determining the scale of artificial oases are issues that must be considered in the development and utilization of land resources in Xinjiang.

2. It has the characteristics of developing characteristic agriculture

The very rich light and heat resources and relatively stable agricultural ecological conditions for oasis irrigation give Xinjiang the objective conditions to develop characteristic agriculture. First of all, water for irrigated agriculture is guaranteed and can be irrigated at the right time and in the right amount according to crop growth needs, laying a reliable foundation for crops to make full use of light and heat resources and soil nutrients to achieve high quality and high yields. At the same time, water resources are relatively stable. The interannual variation coefficient of total surface water runoff in Xinjiang is only 0.13, with a relative variation of 38%. In warm years, the melting of frozen snow in the high mountains provides more supplies, while in the middle and low mountains, precipitation supplies less; in cold and wet years, in the cold and wet years, the middle and low mountains provide more precipitation, while in the high mountains, the melting of snow and ice supplies less. This water supply pattern ensures that Whether in warm or cold or humid years, water resources can play a role in adjusting and supplementing each other, keeping water sources basically stable. Secondly, the abundant light and heat resources are an important guarantee for the development of characteristic agriculture in Xinjiang. Due to drought, less rain, more sunny weather, less air moisture, and high atmospheric transparency, Xinjiang’s solar radiation reaches 130 to 150 km/cm2·year, ranking second only to in the Qinghai-Tibet Plateau. The sunshine hours are long, and the annual sunshine hours are hundreds of hours more than those at the same latitude in China. The daily temperature range is large, and combined with effective irrigation, the water and heat are in the same period. Plants can photosynthesize well and accumulate a lot of dry matter. Therefore, Xinjiang has a good foundation for developing characteristic agriculture. Such as high-quality wheat, corn, rape, sunflower, safflower, peanuts, high-quality cotton, sugar beets, flax, high-quality vegetables, fruits, etc. Therefore, in the development and utilization of land resources, it is necessary to fully grasp the characteristics of Xinjiang's land resources in developing characteristic agriculture.

3. It has the characteristics of fragile ecological environment

Xinjiang is located in the hinterland of Eurasia, with an average annual precipitation of 150 mm, accounting for only 4% of the country's precipitation. Forest and grassland vegetation are mainly distributed in mountainous areas, while the vast plains are desert vegetation. The land is easily desertified and the ecological environment is fragile. The plain area has strong winds for up to 10 to 20 days a year, and sand-generating winds account for more than 15% of the annual wind frequency. It also has abundant sand sources. Strong winds and sand blowing provide dynamic conditions for land desertification, and the threat of desertification is quite serious. Secondly, land salinization is widespread in Xinjiang. Due to drought and lack of rainfall, soil leaching is weak; and due to excessive irrigation and serious water leakage in canal systems, the groundwater level rises. Under strong evaporation, soil salinization is serious. Thirdly, Xinjiang is deep inland. Except for the Irtysh River, Xinjiang’s rivers are all inland rivers. Toxic and harmful substances dissolved along the rivers can only accumulate in the basins, resulting in low self-purification capacity of land resources and easy accumulation of toxic substances. . Therefore, the development and utilization of land resources in Xinjiang must fully consider the fragile ecological environment.

4. The development and utilization of land resources has significant river basin characteristics

The development and utilization of land resources in Xinjiang is developed and utilized according to river basins.

Xinjiang mainly relies on precipitation in mountainous areas, and rivers of different sizes flow into basins. There is very little precipitation in the plains, and oases, agriculture, and ecology all need irrigation. The development and utilization of land resources are distributed according to watersheds due to restrictions on water resources and irrigation conditions. Humans first developed and utilized land in the delta zone downstream of the river. In ancient times, due to backward production tools and low productivity, most projects were developed in downstream areas with flat terrain, developed water networks, and easy water diversion. For example, ancient oases such as Niya and Loulan, which are now buried deep in the desert of the Tarim Basin, were developed in a water-seeking way. With the improvement of people's productivity level and the advancement of water conservancy technology, construction of dams, canals and reservoirs has gradually led to land development and utilization in the middle and upper reaches. As a result, the problem of rational distribution of water resources in the entire river basin has arisen. Due to excessive water diversion for upstream land development and utilization, downstream areas have been cut off, rivers have been shortened, and lakes have dried up. For example, the lower reaches of the Tarim River have been drying up for many years, Lop Nur has dried up, and Lake Aibi has shrunk. This means that land development and utilization have not taken into account the characteristics of the river basin. According to the requirements of the river basin characteristics of land use in Xinjiang, the unified management of land development and utilization first requires the unified management of water resources allocated according to river basins as a basis. Therefore, land development and utilization in Xinjiang requires unified water resources management policies to coordinate with the development and utilization of land resources.

Section 4: Area and Distribution of Oasis in Xinjiang

1. Concept and Classification of Oasis in Xinjiang

(1) Concept and Classification of Oasis

Oasis can be defined as: in an arid desert geographical environment, with stable water sources, abundant light and heat resources, and good soil quality, which can satisfy the normal reproduction of mesophytic plants and is suitable for human sustainability Areas engaged in socio-economic activities.

2. The connotation of oasis

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

(1) Oases are located in arid desert areas.

(2) A stable water source is the basic condition or dominant factor for the existence of an 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 ecological geographical system.

(2) Classification of Oasis

Dividing oasis types will help humans conduct in-depth research on the formation and evolution of oasis, and also facilitate humans to adopt corresponding development and utilization methods and appropriate methods according to different types of oases. construction protection measures.

The division of oasis types should follow the principles of historical evolution, functionality and practicality.

In academia, there are many opinions on the classification of oasis, and there is a lot of knowledge. Due to different classification angles, multi-level classification can be adopted. For example, oases can be divided into natural oases, artificial oases, and semi-artificial oases (or quasi-oasis) according to the degree of intervention by human activities. According to the time scale of formation, it can be divided into ancient oases, old oases, new and old combined oases, and new oases. According to the spatial scale (scale), it can be divided into extra-large oases, large oases, medium-sized oases and small oases; or it can be divided into oasis groups (composed of many oases of the same geographical unit), oasis patches (referring to complete oases of considerable scale) and oasis Points (referring to smaller scattered oases). According to the dominant socio-economic functions, it is divided into agricultural oasis, urban oasis, industrial and mining oasis and animal husbandry oasis.

Limited to the data and work basis, a two-level classification is made based on the principle of being coarse rather than fine: natural oases can be divided into natural forest and grass oases and natural wetland oases; artificial oases can be divided into urban, agricultural, and forest oases. , pastoral oases and industrial and mineral oases. See Table 2-1-3 for details. 2. Area, structure and distribution of oases in Xinjiang

Table 2-1-3 Classification of oase types in Xinjiang

(1) Scope and area of ??oases in Xinjiang

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

Desert areas have sparse precipitation. The climate is arid, with abundant light and heat resources, lack of surface runoff, sparse or no vegetation coverage on the surface, and widespread desert and Gobi desert landscapes.

2. Division of Oasis Scope

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

(1) Signs for dividing oasis:

① Water is the basic condition for the existence of oasis, and it is the source of abundant water (groundwater) in desert areas. , rivers, lakes, etc.), places that can meet the propagation needs of mesophytic and hygrophytic plants belong to the scope of oasis.

② Irrigated agriculture is an important symbol of the existence of oasis. Any area where irrigation channels or pipelines control and reach the remaining irrigation water can satisfy the growth of mesophytic plants.

③The area where trees, shrubs, and meadow vegetation grow along rivers, around lakes, and in swamps in desert areas.

④ Wasteland within the scope of the oasis (such as small pieces of sandy land, saline-alkali land, bare land, grassland, etc.) and abandoned farmland, abandoned channels, roads, homesteads, historic sites, etc. less than 100 hectares of land can be used Included in the oasis area.

⑤ According to the land use type, the surface cover in the oasis includes cultivated land, garden land, pasture (artificial grassland and meadow pasture), woodland (artificial forest, river valley forest), residential areas (towns, townships, Villages) industrial and mining land, channels, reservoirs, lakes, ponds and various roads, cemeteries, etc.

(2) Methods and steps for oasis division:

① Combine the 1975 American Land SatMSS (79-meter resolution), 2000 Land SatTM (30-meter resolution) and The 2005 China-Brazil CBERS (20-meter resolution) (the three places (prefectures) of Kashgar, Ili, and Tacheng have the 10-meter resolution of the French Spot satellite) are accurately registered to Xinjiang 1/ which has been converted into the Albert equal-area conic projection. 250,000 on the topographic map.

② In accordance with the signs of oasis division and the principles of division of natural oases and artificial oases, establish oasis interpretation signs on remote sensing images, and have two interpreters independently interpret the remote sensing images of the same area. , the interpretation type can be determined if the interpretation is consistent, and the type can be determined only after consensus is obtained on the basis of re-interpretation by a third party.

③Based on checking the administrative boundaries of Xinjiang counties, calculate the area of ??various types of oases in each county (city) based on the interpretation of the patterns of various oases, and count them step by step to prefectures (states, cities) ,autonomous region.

3. Calculation results of oasis area

After this survey, the total oasis area in Xinjiang in 1975, 2000 and 2005 was 10.7199 million hectares, 11.5365 million hectares and 12.5929 million hectares respectively. hectares, accounting for 6.49%, 6.79% and 7.63% of Xinjiang’s land area respectively. Among them, the artificial oases are 6.0023 million hectares, 8.6214 million hectares and 9.9806 million hectares respectively, and the natural oases are 4.7175 million hectares, 2.9147 million hectares and 2.6123 million hectares respectively. See Table 2-1-5 for details.

Table 2-1-5 Oasis area in Xinjiang in various periods Unit: 10,000 hectares

4. Changes in the area of ??oasis in Xinjiang

Oasis area is a historical Dynamic data shows that over the past 50 years, the area of ??artificial oases in Xinjiang has continued to expand, until it reached 9.9806 million hectares in 2005, accounting for 6.04% of the total land area of ??Xinjiang. Compared with the beginning of liberation, the area of ??artificial oasis in Xinjiang was approximately 2.25 million hectares in 1949, which expanded to 4.44 times in 56 years. It can be seen that the expansion rate of artificial oases in modern Xinjiang is still very fast. The rapid expansion of artificial oasis area mainly depends on the large-scale development in the north and south of the Tianshan Mountains, especially the development of the Junggar Basin in northern Xinjiang. Before the 1980s, the area of ??artificial oasis in Xinjiang was larger than that in southern Xinjiang; but now, after more than 50 years of development, especially in the past 30 years, the area of ??artificial oasis in northern Xinjiang has exceeded that in southern Xinjiang, accounting for the entire artificial oasis area in Xinjiang. of 49.92%, with Southern Xinjiang relegated to second place, accounting for 46.04%, and Eastern Xinjiang only accounting for 4.04%.

The area of ??natural oasis in Xinjiang is 2.6123 million hectares, accounting for 1.58% of the total land area of ??Xinjiang and 20.74% of the oasis area. Natural oases are mainly distributed in southern Xinjiang, with 1.9711 million hectares, accounting for approximately 75.45% of the total natural oases area in Xinjiang; northern Xinjiang has only 628,000 hectares of natural oases, accounting for 24.04% of the total natural oases area in Xinjiang, mainly distributed in Altay, Tajikistan Cheng and Yili areas; the natural oasis area in East Xinjiang is 13,100 hectares, accounting for only 0.50% of the natural oasis area in Xinjiang.

(1) Regional distribution of Xinjiang oases.

The regional distribution of Xinjiang’s oasis area is shown in Table 2-1-6.

It can be seen from the table:

Table 2-1-6 Oasis area and proportion in Xinjiang region Unit: 10,000 hectares

——From the oasis area In terms of distribution, there are more oasis areas in southern Xinjiang than in northern Xinjiang, and in terms of oasis coverage (that is, the proportion of oasis total area), northern Xinjiang is higher than southern Xinjiang.

——From the perspective of natural oases, the area with the largest area and highest coverage of natural oases is in southern Xinjiang.

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

(2) Ranking of the top 10 counties (cities) by oasis area.

The area (scale) of oasis in Xinjiang varies greatly among counties (cities). In terms of overall oases, Bachu County has the largest area of ??610,200 hectares, which is 277 times that of Wuqia County, which has the smallest oasis area of ??2,200 hectares. Among natural oases, Ruoqiang County has the largest scale, reaching 352,600 hectares; artificial oases The counties and cities with the largest oasis area are Shawan County, Aksu City, Bachu County, Wusu City, Manas, Qitai County, Hutubi County, Emin County, Shache County and Awati County. Shawan County has the largest artificial oasis area of ??443,300 hectares, which is 211 times that of Wuqia County, which has the smallest area of ??2,100 hectares. The ranking of the top 10 counties (cities) in oasis area (scale) in Xinjiang is shown in Table 2-1-7.

Table 2-1-7 Ranking of the top 10 counties (cities) by oasis area in Xinjiang Unit: 10,000 hectares