(Anhui Geological Survey Institute, Hefei 23000 1)
Based on ETM remote sensing data, the present situation of land use in Anhui Province was investigated, the structure and layout of land use in Anhui Province were analyzed, and the utilization potential of land resources was evaluated.
Keywords: current situation of land use; Land resources evaluation; Remote sensing survey
Land is a precious and limited natural resource, a basic means of production for agriculture, forestry, animal husbandry and by-fishing, and an indispensable material basis for production departments such as industry, transportation and urban construction. With the rapid development of economic construction and the acceleration of urbanization, the demand for land is increasing, and the contradiction between man and land is becoming increasingly prominent. Therefore, it is of great significance to use high-tech remote sensing to investigate and evaluate the present situation of land use quickly and economically, so as to rationally utilize land resources, comprehensively plan and protect land, fully tap the potential of land use, and promote the healthy and sustainable development of the national economy.
1 remote sensing survey method of land resources
The remote sensing survey of land resources in Anhui Province belongs to the general survey, which is based on the indoor interpretation of remote sensing images of different land types and the same land type at different times, supplemented by necessary field verification, to investigate the present situation of land use, and to calculate various land use areas and various land use indexes on MAPGIS and other platforms according to the requirements of Technical Specification for Land Use Survey.
1. 1 remote sensing interpretation sign of land type
The remote sensing survey of land use status in Anhui Province mainly takes 1:65438+ 10,000 ETM images in 2000 as the main data source. Due to the complex landform types and diverse land use types in Anhui Province, in order to ensure the accuracy of important land types such as cultivated land, woodland, garden land and residential traffic land, 1986 ~ 1999 color infrared aerial photos and black-and-white aerial photos were used to investigate the sloping cultivated land in mountainous areas, cities and their surrounding areas. The classification principle of land use survey is based on the Technical Specification for Land Use Survey formulated by the National Agricultural Division Committee. The primary classification is divided into 8 categories, and the secondary classification is divided into 4 categories according to the specific situation of land use in our province and the possibility of this remote sensing survey. The first and second land types are merged, and * * * is divided into 12 land types. See table-1 for ETM image interpretation signs of various land use conditions.
1.2 conversion method of small feature area
In principle, the minimum Tu Tu spot area is 2× 3 = 6 (mm2), which is equivalent to the field of view area of 90 mu (1: 65438+ million, but there are still 1238 spots less than 6mm2), that is, 1:65438.
According to the physical and geographical characteristics of the whole province, the whole province is divided into five units: Huaibei Plain, Jianghuai Hilly, Riverside Plane, Western Anhui and Southern Anhui Mountainous Area. Based on1:250,000,1:000,1:50,000 topographic maps, aerial survey and remote sensing data, combined with field investigation, the fine classification correction coefficients in different units are determined.
Remote sensing interpretation marks of land use classification in table 1 ETM images
2 Land use structure and layout
2. 1 land use structure
According to the statistics of remote sensing survey, the total land area of Anhui Province is 140 16595 hectares (2 10248926 mu, the spatial analysis value of MapGIS, the same below), of which 5966237 hectares (89493547 mu) are cultivated land, accounting for 42.57% of the total land area. Garden 34 1775 hectares (5 126632 mu), accounting for 2.44%; Woodland 338 1080 hectares (507 16 193 mu), accounting for 24.12%; Grassland is 37,525 hectares (562,877 mu), accounting for 0.27%; Residential land and industrial and mining land 1267 145 hectares (19007 175 mu), accounting for 9.04%; Traffic land is 273,850 hectares (4 107743 mu), accounting for1.95%; Water area 19978 15 hectares (29,967,223 mu), accounting for14.25%; The unused land is 75 16 18 hectares (1 1274275 mu), accounting for 5.36%. The largest land area is 1843042 hectares (27645623 mu) in Lu 'an, and the smallest is 10604 1 hectare (1590609 mu) in Tongling. According to the population of the whole province in 200 1 year, the per capita land area is 3.32 mu, of which Huangshan City has the largest per capita land area (9.89 mu/person), Huainan City has the least (1.53 mu/person), and most cities have less than 3 mu per capita.
Figure 1 Land Use Structure Map of Anhui Province
2.2 Cultivated land
According to remote sensing survey, the total cultivated land area in the province is 5966237 hectares (89493547 mu), and the cities with cultivated land area of about100000 mu are Chuzhou, Lu 'an, Fuyang, Suzhou and Bozhou. These five cities account for 56 1% of the province's cultivated land area, and Tongling has the smallest cultivated land area (less than 400,000 mu). According to the total population of the province in 200 1 year, the per capita cultivated land area is 1.4438+0 mu; According to the agricultural population, per capita 1.77 mu, per farmer, the average household is 6.87 mu. According to the total population statistics, the per capita land varies greatly among cities. According to the statistics of per capita land owned by agricultural population, only Chuzhou, Bengbu and Huaibei are more than 20% higher than the provincial average, while Huangshan, Anqing, Tongling and Fuyang are more than 20% lower than the provincial average. Chuzhou is the most prominent, with an agricultural population of 3.2 1 mu, and Huangshan is the least, with an agricultural population of 60. Generally speaking, the per capita arable land in the province is quite balanced.
Cultivated land is divided into paddy field and dry land. Paddy fields include irrigated paddy fields and Wangtian, covering an area of 2,562,005 hectares (38,430,070 mu), accounting for 42.94% of the cultivated land area; The dry land area is 3404232 hectares (5 1063477 mu), accounting for 57.06%. In terms of space, the dry land is mainly distributed in Huaibei Plain, accounting for 75% of the dry land area in the whole province, followed by Chuzhou City and Lu 'an City in the east of Jianghuai Hill. Paddy fields are mainly distributed in the hilly areas of the Yangtze River and the plain areas along the Yangtze River, around Chaohu Lake and in the middle, middle and southeast between the Yangtze River and the Yangtze River, with the most concentrated cities such as Lu 'an, Chuzhou, Chaohu Lake, Anqing, Xuancheng, Wuhu, Maanshan and Hefei, accounting for about 90% of the paddy fields in the province. The proportion of paddy fields in Huaibei Plain is small.
2.3 Garden
Gardens mainly include tea gardens, orchards and mulberry gardens. The garden area of the province is 34 1.775 hectares (5 1.26632 mu), accounting for 2.44% of the total land area of the province. The per capita garden in the province is 0.08 mu according to the total population of 200 1. Hefei, Bengbu, Maanshan and other cities 13 are more than 50% below the average level, while Huangshan, Chizhou and Xuancheng are more than 30% above the average level. Huangshan is the most prominent city, with 79,405 hectares (1 19 1077 mu), accounting for 8.2% of its total land area. According to the agricultural population, the per capita garden area is 1.0 1 mu, followed by Lu 'an (57 134 hectares). However, the per capita garden area in Hefei and other cities is only 0.00 1 mu.
Figure 2 Changes of per capita cultivated land area in Anhui Province over the years
Obviously, the gardens in Anhui Province are widely distributed and relatively concentrated in space. Tea gardens and mulberry gardens are mainly distributed in the south of Huaihe River, especially in the mountainous areas of southern Anhui and western Anhui, and orchards are mainly concentrated in Huaibei Plain. Among them, the old course of the Yellow River in Huaibei Plain and its vast area are the main fruit producing areas in Anhui Province.
2.4 Woodland
There are 338 1.080 hectares (507 1.6 1.93 mu) of forest land in the province, including forest land, shrub land, sparse forest land, gardens and nurseries. , accounting for 24. 12% of the total land area of the province. Huangshan City has the largest forested area, accounting for 696,244. It accounts for 7 1.9% of its total land area, followed by Xuancheng 629606 hectares (944087 mu), Lu 'an 589773 hectares (8846599 mu) and Anqing 56 14 1465438 hectares (842/kloc-0). From the perspective of per capita ownership, there are great differences among cities. The average per capita of Huangshan City is 7. 1 1 mu, while that of Bengbu City is only 0.03 mu, a difference of more than 200 times.
In a word, the spatial distribution of forest land is obviously neutral, mainly distributed in southern Anhui and western Anhui.
2.5 grassland
The province has 37,525 hectares (562,877 mu) of grassland, including natural grassland and artificial grassland, accounting for only 0.27% of the province's land area and 0.009 mu of grassland per capita. The largest grassland area is Chuzhou14,835 hectares (222,530 mu) and Huangshan13,557 hectares (203,355 mu), while there are almost no large grasslands in Bengbu and other cities. The spatial distribution of grassland in the province is highly dispersed, with different areas. Most small plots are not on the map, and there are farmland and woodland mixed.
2.6 Residential land and industrial and mining land
The total residential land and industrial and mining land in the province is 1267 145 hectares (19007 175 mu), accounting for 9.04% of the total land area in the province. Based on the population of 200 1 year-end, the per capita residential land and industrial and mining land in rural areas are slightly higher than the provincial average, and most of them are smaller than those in cities. Lu 'an 14007 1 hectare (21kloc-0/068 mu) with a large residential land and industrial and mining land area, and Tongling 1 1877 hectares (17868 mu) with the smallest. The per capita possession of most cities is between 0.22 and 0.32 mu, and only Chuzhou is larger (0.458 mu). In a word, the per capita possession of residential land and industrial and mining land in cities in Anhui Province is relatively close, and the per capita possession in rural areas is greater than that in cities.
2.7 traffic land
The transportation land in the province is 273,850 hectares (4 107743 mu), accounting for 1.95% of the total land area in the province. In 2006, the per capita population was 0.065 mu, 438+0. The largest traffic area is Suzhou with 33,805 hectares (507,077 mu), and the smallest is Maanshan 1700 hectares (2,5501mu). The per capita area is the largest in Bengbu (0.11mu) and the smallest in Maanshan (0.02 1 mu). Generally speaking, the traffic land in the north is larger than that in the south, and the plain is larger than the mountainous area.
2.8 waters
Waters include rivers, lakes, reservoirs, pits and ponds. The water area of the province is 19978 15 hectares (29,967,223 mu), accounting for 14.25% of the total land area of the province, with a per capita of 0.474 mu 200 1. Anqing has the largest water area, with 3 18389 hectares (4775828 mu), followed by Lu 'an with 259869 hectares (3898033 mu), Chaohu with 2 18632 hectares (3279484 mu) and Chuzhou with 2 15787 hectares (. Chizhou has the largest per capita water area (0.839 mu), Huaibei has only 0. 195 mu, Fuyang has 0. 196 mu, Bozhou has 0.234 mu and Suzhou has 0.264 mu, which are far below the provincial average. Obviously, the water distribution of the vast Huaibei Plain in Anhui Province is very small both in total and per capita.
2.9 Unused land
The unused land mainly includes grassland, saline-alkali land, ridge, bare rock (gravel) and so on. The province's unused land is 75 16 18 hectares (11274,275 mu), accounting for 5.36% of the province's total land area, and the population at the end of the year is 200 1. The unused land is mainly distributed in Chaohu City (12 1 147 hectares) and Chuzhou City (105 196 hectares). 93,995 hectares in Lu 'an (1.409,927 mu), 90,748 hectares in Anqing (1.365,438 mu) and 87 hectares in Chizhou (65,438 mu+0.307,989 mu). These six cities have no land in the whole province. The largest per capita unused land is Chizhou (0.85 mu), and the smallest is Fuyang (0.0 1 mu) and Bozhou (0.0 1 mu). Generally speaking, the total amount and per capita possession of unused land in the northern plain is much lower than that in western Anhui, southern Anhui, along the Yangtze River and Jianghuai areas.
3 land resources evaluation
3. 1 favorable conditions for land use
Mountains, hills, hills and plains in Anhui Province are distributed alternately, and the landform types are complex and diverse. From north to south, it is Huaibei Plain, West Anhui Mountain and Jianghuai Hills, Riverside Plain and Southern Anhui Mountain Hills. The complex landscape pattern forms a variety of land types, and the main land resource types are relatively concentrated. Climate, soil and vegetation have obvious characteristics of north-south transition, which makes the land use types and farming systems in this province bear the brand of north-south transition. Strong land suitability and high natural productivity. These specialized production and the comprehensive development of regional agriculture in Anhui province have created a good and diversified natural environment for choosing suitable land use methods and making full use of land resources.
Anhui province is located in the transition zone between north and south, and its social economy is also in the transition zone from the developed economic zone in the eastern coastal area to the backward economic zone in the western inland area. Economic development will accelerate the comprehensive development and utilization of land resources in Anhui Province and improve the economic benefits of land use.
3.2 land development and utilization degree and economic benefit analysis
(1) Land reclamation rate: that is, the ratio of cultivated land area to total land area, and the province's reclamation index is 42.57%, which generally reflects the height of land development and planting development in Anhui Province. However, there are great differences in reclamation indicators among cities. Bozhou City has the highest reclamation index, reaching 70.70%, followed by Fuyang City, Huaibei City, Bengbu City and Suzhou City, with indexes above 60.00%, and Huangshan City has the lowest reclamation index, accounting for only 8.90%.
(2) Land utilization rate: that is, the ratio of the utilized land area to the total land area, and the average land utilization rate in the whole province is 94.64%. Obviously, the land utilization rate in Anhui Province is very high, and the land utilization rate in Bozhou City reaches 99.70%. The utilization rate of other cities is in a high state, and the difference is not significant.
(3) Construction land rate: the construction land rate is the ratio of residential land+industrial and mining land+traffic land to total land area, and the construction land rate in the whole province is also at a high level, with an average of 10.99%, and the growth rate of construction land is relatively high. The construction land rate varies greatly in different cities. The highest is Huainan City, 18.8%, and the lowest is Huangshan City, 3.8%. The indexes of Chizhou and Xuancheng are also very low.
(4) Land productivity: GDP per unit area, that is, land productivity, can roughly reflect the macroeconomic effects of land in Anhui Province. The land productivity in Anhui province is 234.73 million yuan per hectare (output value is 200 1). There is a big difference among cities, the highest is Maanshan, which is 8 1, 26 1, followed by Tongling, Wuhu, Huainan and Hefei, all of which are more than twice the provincial average, while Chizhou, Huangshan and Lu 'an, which are on the low side, are less than 1 000 yuan.
3.3 The main problems of land use
For decades, Anhui Province has made great achievements in the development and utilization of land resources and the development of agricultural production. However, compared with some neighboring provinces, the production level of agricultural land resources is still low, and the land productivity in some cities is not high, and the potential of land resources has not been fully exerted. The main problems existing in the current land use are:
(1) irrational land use structure, low land productivity and low economic benefits. For a long time, due to over-emphasis on the development of planting industry, the structure of agricultural output value and land use in Anhui Province are not in harmony, and many types of land resources, especially mountainous areas and water surfaces, have not been fully utilized, and the output value of forestry and fishery is not in harmony with its area composition. Although the province has concentrated a lot of manpower, material resources and financial resources to produce grain, its agricultural production, especially grain production, is still at a low level due to frequent natural disasters, many land obstacles, poor labor quality and less investment in science and technology. In addition, the average plot ratio of cities and towns in Anhui Province is only about 0.3, and the land used in cities and towns and independent industrial and mining areas is extensive, resulting in poor economic benefits per unit area.
(2) The contradiction between land supply and demand is prominent, especially the shortage of cultivated land and the serious shortage of land reserve resources. In the land structure of the province, the proportion of cultivated land is much higher than the national average, but the per capita cultivated land is very limited. Calculated by 200 1 population, the per capita arable land is only 1.4 1 mu (including low-quality production areas). Anhui province has a long history of agriculture. Cultivated land resources are fully utilized, and the proportion of unused land is low, mainly distributed in remote mountainous areas. It is difficult to develop and utilize, and the reserve cultivated land resources are very limited. In addition, Anhui Province is in the early stage of industrialization. With the acceleration of industrialization and urbanization, residential areas, industrial and mining and traffic construction will continue to occupy a large number of cultivated land, and the situation of cultivated land is not optimistic.
(3) Land pollution is serious, industrial wastewater and pesticides pollute farmland, industrial waste residue and domestic garbage occupy a large amount of land, unreasonable underground mining causes ground collapse, and the discharge of harmful gas and dust forms acid rain, which all lead to the destruction of land resources. Especially in the 1990s, the use of pesticides increased year by year, but the area and extent of crop diseases and insect pests increased obviously, forming a vicious circle in some areas. Pesticides have caused substantial pollution to soil, air, water and crops, and pesticide residues in grain, fruits and vegetables in many areas have seriously exceeded the standard.
(4) The uneven distribution of water resources has not alleviated the serious water shortage in Huaibei plain and hilly areas, which has seriously restricted the development and utilization of land resources.
(5) Land rights are excessively dispersed, and tens of millions of farmers own their own fields, which is rare in today's countries. The circulation of rural land has not been pushed away, and the land has lost its inherent assets and commodity attributes, which is also a factor restricting the transformation of Anhui Province from a large agricultural province to a strong agricultural province.
3.4 land use potential analysis and countermeasures
The potential of land resources refers to the breadth and depth that human beings can achieve in developing and utilizing land resources under certain social and economic conditions, including natural production potential and transformation and utilization potential. Anhui province is populous and sparsely populated. Although the suitability of land resources is good, the overall land quality is not high and the land reserve resources are insufficient. Therefore, analyzing the potential of land resources, rationally utilizing land resources and improving land productivity are the fundamental strategies for land planning and utilization in Anhui Province.
3.4. 1 cultivated land
The natural production potential of land resources is the amount of materials that can be produced by natural fertility and natural supply conditions such as water and heat, and Anhui Province is still a high-value area. The north of Huaihe River has a warm temperate semi-humid monsoon climate, and the south of Huaihe River has a subtropical humid monsoon climate. This superior climate resource is not only suitable for the growth of cool crops such as wheat, rape and leguminous crops in the afternoon, but also beneficial to the cultivation of isothermal crops such as rice and cotton. The natural productivity of land in the whole province is decreasing from south to north, and the natural productivity potential of several major agricultural areas (see Table 2).
Table 2 Division of natural production potential of land resources in Anhui Province
Anhui province has a large land reclamation coefficient, and there is little room for expansion of cultivated land utilization. With the needs of ecological planning such as returning farmland to forests, grasslands and lakes, the area of cultivated land will decrease with the increase of urban and rural construction land. However, due to the level of land management and the natural, economic and technical conditions of production in Anhui Province, crops are far from reaching the upper limit of their productivity. Therefore, the potential of cultivated land is still great. It is suggested that the following measures and ways should be taken to tap the potential of cultivated land utilization:
First, give priority to the capital construction of farmland water conservancy, supplemented by measures to increase fertilizer and improve soil, and improve medium and low-yield fields. The area of cultivated land in Anhui Province is the largest in Huaibei Plain, and the proportion of medium and low yield fields is significant (765,438+0%). The main influencing factors are irrigation conditions and soil fertility. It is necessary to combine drainage and irrigation, combine drought and flood, and develop dry farming and supplementary irrigation; Increase fertilizer, especially organic fertilizer, adjust the ratio of nitrogen, phosphorus and potassium, and improve the fertilization structure.
Second, continue to popularize new technologies, vigorously carry out scientific farming, scientific seed selection, breeding, cultivation, fertilization, irrigation, and pesticides, quickly transform agricultural scientific and technological achievements into productive forces, gradually improve the quality of agricultural labor, and increase various agricultural inputs.
Third, protect the environment, attach importance to the improvement of the external environment of farmland, do a good job in afforestation, surrounding greening and farmland shelterbelt network construction, and establish a virtuous circle of farmland ecosystem.
Fourth, adjust the crop structure, rotate crops rationally, and appropriately increase the multiple cropping index.
3.4.2 Garden
Vegetable garden is the production land of cash crops such as tea, mulberry and fruit. The climate in this province is superior, and the landform and soil types are complex and diverse, which is suitable for the production and cultivation of cash crops such as tea, mulberry, fruit, medicinal materials and mint. There are 34 1.800 hectares of various gardens in the province, accounting for only 2.44% of the total land area. The park occupies less cultivated land and has poor site conditions. About 80% is built on the basis of developing barren hills, slopes, wasteland, wasteland and "four sides". Soil fertility, fertilizer and water conservation performance, poor irrigation conditions and inconvenient transportation. The proportion of low-yield gardens in existing gardens is relatively high, accounting for 56.6% of the total garden area, while the proportion of famous, excellent and special products is not large, and the level of large-scale and intensive management is not high. According to the actual situation in Anhui Province, the suggestions are as follows: First, tap the potential, transform low-yield gardens, and improve product quality and output; Second, increase material and technical input, strengthen scientific management, and newly (expand) build a variety of cash crop bases such as tea and mulberry fields; The third is to strengthen the research on land suitability, gradually expand the area of famous, excellent and special gardens, and increase the total number of famous, excellent and special genera to meet market demand.
In addition, the regional distribution of tea, mulberry, fruit and medicinal materials in the province should be reasonable, and the development of major agricultural areas should be focused on each other. Huaibei plain is the main development area of fruits, medicinal materials and mint, so sericulture production should be actively and steadily developed; Dabie mountain area in western Anhui is an important development area for cash crops such as tea, mulberry and medicinal materials. The hilly area in southern Anhui is an important base for cash crops such as tea, mulberry, fruit and medicinal materials, and it should also be the main production base for efficient agriculture and foreign exchange earning agriculture in Anhui Province. The hilly area of Jianghuai is suitable for planting cash crops such as fruits, mint and medicinal materials. The plain areas along the Yangtze River should focus on developing cash crops such as fruits, flowers and tea.
woodland
Forest is an important natural resource for human survival and development, which not only has direct economic benefits of providing wood and forest by-products, but also has ecological and social benefits such as water conservation, soil and water conservation, wind and sand fixation, climate regulation, air purification, tourism and health care. In 1990s, Anhui forestry maintained a sustained, stable and healthy development trend, making it the fourth province in China to completely eliminate barren hills suitable for forest and basically afforest. In particular, plain forestry started from Huaibei agricultural area and gradually advanced to Jianghuai hills and plains along the river, and the province initially established a perfect farmland shelterbelt system framework. Whether in mountainous areas, hills or plains, forest resources have greatly increased and entered a virtuous circle. According to investigation and statistics, the existing forest land area in Anhui Province is 338 1.08 hectares, accounting for 24. 12% of the total land area, and the per capita forest land is 0.8 mu, far below the national average. The total amount of forest resources in Anhui Province is still insufficient, the forest quality is poor, the advantages of forest products have not been formed, the proportion of forestry output value in the economic composition is too small (even stagnant after 85 years), and the level of forestry productivity is not commensurate with the better natural conditions as a key province in southern collective forest areas. Therefore, it is suggested that: first, improve the utilization rate of forest land, speed up the transformation and tending of forest land, make irrigated and sparse forest land become forest land as soon as possible, and speed up the transformation of low-yield forest land; Second, continue to do a good job in returning farmland to forests, expand the area of economic forests, and attach importance to the development and utilization of sporadic barren hills and wasteland; Third, we will further promote the afforestation project without forest land in Huaibei, Jianghuai and riverside areas, and pay attention to the unity of forestry ecology and economic benefits. Fourth, establish a big agricultural concept, deepen the development of non-wood resources and realize the adjustment of forestry structure.
3.4.4 Grassland grazing
Grassland in Anhui Province is mainly forest (agricultural) grassland and forested grassland. The quality of grassland is poor, and many grasslands are still in the stage of natural utilization, with low productivity and failure to tap the production potential. A small part of the grassland is naturally grazed, and most of it is not developed and utilized, resulting in a great waste of resources. The grassland to be developed and utilized in the province is large in area, diverse in grassland types and rich in forage resources. The distribution of grassland is more conducive to the comprehensive development of agriculture, animal husbandry and forestry, and has become a large-scale and efficient agricultural ecosystem. Dabie mountain in western Anhui and hilly land in southern Anhui, among which Xuanlangguang hilly land and Guichi grassland are of great development value. Other lakes, beaches and sandbars also have good seasonal grasslands. It is suggested to continue to expand the pasture area of Huangshan and Guichi. Attach importance to the improvement of the existing grasslands in the province, introduce high-quality pastures, and improve the grassland carrying capacity. In the overall layout of animal husbandry development, the imbalance between the number of herbivorous livestock structures and the distribution of grasslands in southern and northern Anhui will be gradually solved, and the transformation of local agricultural production methods will be guided.
Feasible water surface
The province has a mild climate, abundant rainfall, vast water surface, Yangtze-Huaihe River crossing, numerous lakes, dotted ponds and criss-crossing ditches. 200 1 year, the output of aquatic products in the whole province is/kloc-0 1.5994 million tons, and the per capita possession of aquatic products is 25.3 kilograms. The output of aquatic products is growing rapidly, and the proportion of water output value in economic composition has been greatly improved in recent years. However, the potential of water resources in our province is still great, the utilization rate of water surface is not high, the proportion of low-yield water surface in water surface is high, and the area of barren water surface is large. It is suggested to improve the utilization rate of arable water surface; Transform the stable deep subsidence in the coal mining area into a water surface that can be raised, and expand the water area in many ways. In addition, in Chaohu Lake and other waters, grass carp farming and other ways will be developed to promote the improvement of the ecological environment.
3.4.6 Construction land
The per capita comprehensive land use index of cities and towns in Anhui Province is reasonable, but the growth rate is relatively fast. Generally speaking, in urban land, public facilities and green land are generally insufficient. The residential land in towns (including villages) is generally too large, which is caused by the slow transformation of old cities and the low level of buildings in small towns and villages in some places. There is a lot of idle land in the market town. There is enclosure waste in economic development zones. About 80% of the village construction land is suitable for arable farmland, and the proportion of library plus land exceeds 10% of the village land. The vast majority of cultivated land occupied by township enterprises has convenient transportation, close to water sources, good arable property, and there is also a phenomenon of land occupation and waste. Traffic land has increased rapidly in recent years, with expressway and rural roads accounting for a large proportion.
Cities such as Hefei, Xuancheng and Wuhu have expanded rapidly, and the built-up area of Hefei delineated by two remote sensing images in 2000 and 1990 has more than doubled. However, the expansion of construction land is inevitable, and the excavation of construction land potential focuses on rational planning and reducing waste.
In short, in the future land use of Anhui Province, firstly, we should adjust the structure of agricultural land, fully tap the potential of land use, and pay attention to ecological construction while comprehensively improving agricultural productivity; Second, it is necessary to rationally plan construction land, especially tap the potential of existing urban land, give full play to the leverage of construction land supply in regulating social and economic development, strive to enhance the economic functions of large towns, and curb the strong expansion of residential functions in recent years.
refer to
[1] Anhui Provincial People's Government. Anhui Yearbook (200 1). Anhui Yearbook Publishing House, 200 1.
[2] Anhui Provincial Bureau of Statistics, Anhui Statistical Yearbook (2002). Beijing: China Statistics Publishing House, 2002.
[3] State Bureau of Technical Supervision. Technical specification for summary of urban land use status [TP 1002-93]
[4] Office of the Leading Group for Overall Land Use Planning in Anhui Province. Special research report on overall land use planning in Anhui province 1993
Remote sensing survey of land use and evaluation of land resources in Anhui Province
Chen Youming, Yang Zedong, Chu Jinhai, Lu, Liu Tongqing, Yang Peiming
(Anhui Geological Survey Institute, Hefei 23000 1)
Based on ETM remote sensing data, this paper investigates the present situation of land use in Anhui Province, analyzes the structure and layout of land use in Anhui Province, and evaluates the utilization potential of land resources.
Keywords: current situation of land use; Land resources assessment; Remote sensing survey