this connection is mainly obtained from the comparison between the old and new classification systems.

The biggest difference between the national standard of Classification of Land Use Status and the original classification system issued by the Ministry of Land Classification (Trial) is that the national standard adopts two levels, one of which is equivalent to the second level of the standard of Land Classification (Trial)

, and the second level is equivalent to the third level of the standard of Land Classification (Trial), that is, it has been cancelled.

1.1 part of agricultural land

The national standard of Classification of Land Use Status further summarizes the types of agricultural land. However, compared with Land Classification (Trial), the current land classification still has some inadequacies.

(1) In the part of "cultivated land", firstly, the original "irrigated paddy field" and "Wangtiantian" were merged into "paddy field". From the meaning of paddy field, this actually cancelled the classification of "Wangtiantian". In fact, although the area of Wangtiantian has decreased with the implementation of the measures of returning farmland to forests and grasslands in various places, the area of Wangtiantian in China is still relatively large, reaching more than 31 million hectares in 2117. In other words, Wangtiantian still occupies an important position in China's strategic goal of adhering to the red line of 1.2 billion hectares of cultivated land and should not be banned. Secondly, the vegetable field was cancelled, that is, the vegetable field was merged under the irrigated land. From Du Neng's agricultural location theory in "Isolated Country", we can know that the area closest to the city and the market is mostly planted with vegetables, horticultural crops and other crops, while irrigated land is mainly distributed in rural areas in the outer circle. Obviously, the distribution of the two is obviously different, especially around the city. Confusing vegetable fields and irrigated land in general will confuse the intensive management degree of different lands, which is not conducive to urban planning and "vegetable basket"

(2) In the "Garden", "Mulberry Garden and Rubber Garden" were merged into "Other Garden". In some southern provinces of China, there are large areas of mulberry orchards and rubber orchards, and some of them belong to pillar industries, such as rubber industries in Hainan and Xishuangbanna, Yunnan. Therefore, this combination and classification is not conducive to the research, planning and management of all kinds of gardens, nor to the classification and guidance of the production of all kinds of gardens.

(3) The part of "woodland" is classified into three types of "forested land, shrubbery land, sparse woodland, uncultivated afforestation land and nursery", that is, sparse woodland, uncultivated afforestation land, sparse woodland and nursery are merged into "other woodland". However, the management methods of the above four types of forest land are completely different. As far as the plot and nursery are concerned, the plot refers to the land that has not been updated within 5 years after forest logging and fire. Nursery refers to a fixed tree nursery, which is not only very different in concept, but also obviously different in management measures. Once the same land type symbol is used on the survey map of land use status, it is impossible to distinguish which spot is a tree-lined nursery and which spot is a "barren" plot.

In order to restore forest vegetation, some provinces have specially launched the "Year of Regeneration of Landmarks", clearly stating that the regeneration of woodlands is an important content of forest management according to law, an urgent need to cultivate forest resources, and an inevitable requirement to promote the construction of an ecological province. The cancellation of these forest land types is not only unfavorable to the management of forestry departments, but also unfavorable to obtaining reliable scientific data.

(4) The adjustment of "grassland" is relatively large. In the new land classification, the original "grassland" has become the current "grassland", and the artificial grassland and improved grassland have been merged into "artificial grassland", and at the same time, a new land type "other

grassland" has been added, which refers to the tree canopy density <: 1.1 The surface layer is soil, mainly herbaceous plants, which are not used for animal husbandry. The "other grassland" is actually the grassland in the "unused land" in Land Classification (Trial). This is obviously inappropriate, because the grassland has always been regarded as the available land in the "unused land", the most basic and precious reserve land resource, and the main object of land development and consolidation and supplementary cultivated land. If the "grassland" is classified as "grassland", it will inevitably lead to great confusion in land development and consolidation, and the normal development of grassland is likely to be regarded as the act of destroying grass and reclamation and destroying ecology. In this way, it is not conducive to the implementation of the policy of "balance of occupation and compensation" of cultivated land, and will pose a severe threat and challenge to China's strategy of sticking to the red line of 1.2 billion hectares of cultivated land < P >.

1.2 part of construction land

The national standard of Classification of Land Use Status further subdivides the part of "construction land": the part of commercial service land is changed from the original "commercial land, financial insurance land, catering hotel land and other commercial service land" to "wholesale and retail

land, residential catering land, commercial finance land and other commercial service land", with the name. The part of industrial, mining and storage land has not been changed; The part of residential land is classified into two categories: urban residential land and rural homestead from the original four categories. This adjustment obviously avoids the original problem that it is not suitable to operate between single residence and mixed residence and whether it is idle or not in the actual investigation. The land for public management and public service is partially adjusted to 8 categories; In the part of special land use, the name "burial land" was changed to "funeral land", which is more accurate; In the transportation land, "rural roads" originally belonging to "other agricultural land" have been added, which embodies the principle of urban-rural integration and realizes the "full coverage" of land classification; The water area and land for water conservancy facilities are partially adjusted to 9 secondary types, such as "river water surface, lake water surface, reservoir water surface, pit water surface, coastal beach, inland beach, ditch, hydraulic construction land, glacier and permanent snow". The "tidal flat" is subdivided into "coastal tidal flat and inland tidal flat", and the original "farmland water conservancy land" is changed to "ditch"; Cancel the "reed land" [3]. In this classification, there are still some problems in some land types, mainly as follows.

(1) In the original classification system, the "landscape leisure land" included scenic spots, revolutionary sites, scenic spots, parks, squares, public green spaces, etc. In the new classification system, it was renamed as "land for scenic spots and facilities", specifically referring to the construction land for scenic spots (including scenic spots, tourist attractions, revolutionary sites, etc.) and management institutions. Other land in the scenic area is classified into corresponding land types according to the present situation. This regulation is too general, and specific regulations should be made for other

land in the scenic spot to avoid the situation that ponds, lakes and other water surfaces in the scenic spot are classified as "pit pond water surfaces".

(2) In the new land classification, a brand-new land type-Kugaji was put forward. Kugaji's proposal is a bright spot, which reflects the government's determination to make greater efforts to economize and rationally use every inch of land. However, from the meaning of "idle land", it is not difficult to find that Kugaji refers to the unused land in towns, villages and industrial and mining areas. Therefore, the division of "Kugaji" is too general. We believe that "Kugaji" should be further subdivided and the three types (town Kugaji, village Kugaji, industrial and mining Uchikoga) should be listed one by one, so as to better predict the utilization potential of all kinds of construction land, better plan, develop and utilize it, and avoid the odd situation of granting residential land to industrial and mining Uchikoga

.

(3) From the concept of bare land, it can be seen that the newly classified "bare land" is actually a combination of bare land and bare rock gravel land under the second-class "unused land" in the original classification. Bare land refers to the land with soil surface and basically no vegetation cover, which belongs to profitable land. Bare rock gravel land refers to the land whose surface layer is rock or gravel, and its coverage area is ≥71%, which is difficult to use. It is easy to see their differences from their definitions, which also determines their different development and utilization directions, but here they are confused, which is not conducive to analyzing the scope, scale and structure of available land and difficult-to-use land. Therefore, it is suggested that the two should be investigated separately, so as to formulate the corresponding development and utilization direction and measures and make full and reasonable use of them.

2 Discussion and suggestions

The introduction of the national standard of Land Use Status Classification means that the classification standard of land use status has risen from the past industry standard to the national standard, which provides a reliable method to solve the problems of repeated land survey statistics, multiple statistics and different calibers, and is of great significance to the scientific management of land resources and even the macro-management decision of the national economy [4]. It marks the deepening of land use research and the improvement of land management level in China, and it is also the concrete embodiment of implementing the strictest land management system in China. However, this land use classification inevitably has shortcomings, which requires continuous improvement and perfection in the future land resources investigation practice and land use research, so that it can better serve the development, utilization and management of land resources in China. The above comparative analysis shows that the land types that need to be improved in the national standard of Land Use Status Classification are mainly as follows.

(1) It is not appropriate to cancel the two secondary categories of "Wangtiantian" and "Vegetable Field" in "cultivated land".

(2) "Mulberry Garden" and "Rubber Garden" should not be merged into "other gardens", but should still be regarded as two secondary categories under "gardens".

(3) In "other woodlands", it is better to further divide four secondary categories, namely sparse woodlands, young woodlands, trails and nurseries, so as to manage and protect all kinds of woodlands in different categories.

(4) Dividing the "grassland" from the original "unused land" into the current "grassland" is not conducive to the implementation of land development and consolidation projects and the implementation of the policy of "occupation and compensation" of cultivated land, so it is appropriate to keep the "grassland" as a backup land resource.

(5) The new classification system cancels "other agricultural land". Although it has a positive side, it is obviously inappropriate to combine natural waters with artificially constructed land for water conservancy facilities, which needs further discussion and research.

(6) In the new classification system, specific provisions should be made for other land in the scenic spot to avoid confusion in land classification caused by this general classification.

(7) The "Kugaji" in the new land classification fails to list the towns of Kugaji, villages of Kugaji and industrial and mining areas of Uchikoga one by one, so it is impossible to accurately analyze the utilization potential of all kinds of construction land, and the application value of the survey results is sharply reduced. It is suggested that the investigation should be further divided into three tertiary land types: Kugaji, Kugaji and Uchikoga.