1 Project background
In order to protect the lawful rights and interests of property owners of self-built houses in urban areas, and to fully grasp the construction status of self-built houses by urban residents, it provides an accurate and reliable basis for formulating annual housing supply plans and mid- and long-term real estate development plans. According to the "Property Law" of the People's Republic of China, " Laws and regulations such as the Urban Real Estate Management Law and the Urban and Rural Planning Law carry out census work of self-built houses for urban residents. Housing census work includes real estate survey, real estate surveying and mapping and establishment of real estate geographic information system (also called real estate GIS )
2 Property survey
The purpose of real estate investigation is to obtain various element information of real estate, to confirm the property rights and attribution of real estate and land use through confirmation of authority, quality and quantity of property, and finally to establish various real estate files to provide a reliable and direct service basis for real estate management data.
The real estate survey is carried out in communities, with Qiu as a unit. Investigation rights holder information (name, ID card number, work unit, number of households, household registration location); real estate status and registration information (land registration information, house registration information, planning permission information); house division information (name, structure, floor Number, building area, year of completion, planned use), the above information is completely filled out in the "House Census Registration Form", after the right holder confirms that the content is true, sign and confirm.
3 Real Estate Surveying
The main result of real estate surveying and mapping is the real estate map. The real estate map is an important data for real estate property rights and birth registration management, and it is also the basis for editing real estate plots, plots and household maps. According to the needs of real estate management, it is divided into sub-plans (referred to as sub-pictures), real estate sub-plans (referred to as sub-qiu maps), and real estate layered household plans (referred to as households maps).
The surveying and mapping method of real estate sub-maps adopts digital mapping technology, and its surveying and mapping content includes administrative boundaries, hill boundaries, houses and their auxiliary facilities, real estate elements and real estate numbers, and topographic features. Compared with the general topographic maps, the surveying and mapping of real estate subdivision maps are not fundamentally different. They are mainly based on real estate survey data and focus on highlighting real estate elements and ownership relationships to determine the ownership boundaries of house ownership and land use rights. Accurately reflect the current status of house and land use, and accurately measure the building area and land use area. The real estate sub-map is a partial detail map of the real estate sub-map, which is to use the real estate sub-map and the real estate survey data to draw the boundary points according to the range of Benqiu, depict the features of the house, and measure the length of the boundary and the house Side length, etc., draw a picture. The real estate division plan is to directly use the real estate division map as the working map, to carry out on-site measurement according to the mounds, buildings, and floors, and to draw the real estate layered household plan.
4 The establishment and application of real estate geographic information system (GIS)
Real estate geographic information system In order to realize the management mode of "manage house with pictures and text", the establishment of real estate data geographic information system is the foundation of real estate GIS system management. The quality of real estate geographic information system directly affects the application of GIS system . The real estate geographic information system basic platform uses ESRI's ARCGIS10.1, and the database platform follows SQL Server2005. These software platforms have rich and comprehensive functions and scalable solutions. In the future, they will fully meet the development of the real estate management department's geographic information system construction. , Its system platform also has good stability and scalability.
4.1 Property code
All houses should be coded. The house code is 26 characters, consisting of administrative division code (9 digits), building number (12 digits), household number (4 digits), and inspection code (1 digit).
Adopt division and mound method, building code is composed of real estate zoning code ( 4 digits), mound number (4 digits), building number (4 digits), such as: 32032400100010001000100011.
4.2 Operation process
The operation process of building real estate geographic information system for real estate data is shown in Figure 1.
4.3 Operation method
4.3.1 Division of layers
Combined with the actual needs of the real estate geographic information system, the basic graphic data is divided into the following layers, as shown in Table 1.
Table 1 Real estate GIS layer division table
Figure 1 Operation flow chart
4.3.2 Operation method
( 1) Collation of basic data
The basic graphic data is stored in the ( dwg) format, which is a digital topographic cadastral map for the two-tone results, combined with the requirements of the real estate specification, delete the cadastral elements, and retain the various elements required by the real estate graphics.
The basic data also includes an electronic version of the household map, a scanned copy of the household drawing, a photo of the house, and a paper scanned copy of the census form. The above data is organized by the community and stored in units of mounds.
( 2) Labeling real estate elements
The basic graphic data refers to the census data in the house census table, and the real estate elements are layered on the graph in the order of hills and buildings, as shown in Figure 2.
Figure 2 Annotated real estate element map
( 3) Real estate property entry and import
With reference to the census data in the house census table, various elements are entered into a table format ( xls), see Figure 3. Import the attribute data after inspection and import it into the database in units of communities.
( 4) Conversion of graphic data
The graphics completed by the labeling of real estate elements adopt the (DWG) data format. In order to meet the requirements of the real estate geographic information system source data, the attributes of the real estate elements are associated with the attributes of the owners, hills, and buildings, and then converted to (shp) format.
( 5) Import graphics into database
According to the community, import the shp format files into the temporary database of the real estate GIS system. After the review, enter the real database of the real estate system.
( 6) Picture data upload and check
Upload the electronic version of the household map, the scanned copy of the drawings of the household, the photos of the house, and the scanned paper of the census form to the real estate GIS system according to the community , and check them hill by hill.
( 7) Layered modification of GIS graphics
The graphics imported into the real estate GIS system are only hills and buildings, and the administrative divisions, roads, water systems, and vegetation layers of the real estate basic map are extracted layer by layer, and the overlay map is combined with the aerial image within the superimposed range. , Mark the point of interest on the graph of the real estate GIS, set the color, style, display level, etc. of each element, as shown in Figure 3.
Figure 3 Real estate GIS map
( 8) Output of results
Through the real estate GIS system, you can view the real estate file according to the mound number, survey number, right owner query, positioning graphics; count the real estate area; output real estate forms and other data.
4.4 System application
After the completion of the system, coordinated positioning and drawing of the gallery are carried out for each house (location). The basic elements of the house are combined with effective information. On the one hand, it is linked to the house registration system to truly integrate the house with the picture management and picture; the other On the one hand, the basic condition of the house can be counted.
The main functions of the GIS system include: system management, layer control, query positioning, statistical analysis, thematic maps, historical data comparison, data import, real estate table management, data editing and other functions. The following mainly introduces the functions of query positioning and statistical analysis. Mainly introduce query positioning, statistical analysis functions.
4.4.1 Query positioning
Query the basic information and house information of the house owner and locate on the GIS map of the house . According to any one of the provided name, ID number, mound number, and survey number, you can specify the community to query, or you can arbitrarily delimit the range. After the query, the graphic is directly located to the household, see Figure 4.
Figure 4 Status of the house
After locating to the household, you can obtain the household's house information (hill information, building information, house survey information, house photos, etc.), see Figure 5.
Figure 5 Housing information
4.4.2 Statistical analysis
Statistics can be made by administrative area, arbitrary area or simulated area respectively.
( 1) Statistics of administrative regions. According to the statistical items in the system, all the housing information of the designated community can be counted.
( 2) Statistics in any area. Define any area for house information statistics within this range.
( 3) Statistics of simulated areas
A. Linear engineering application. When a road or river needs to be opened, widened or extended, the system can simulate and deduce the information related to house demolition according to the set length and width to generate a thematic map.
B. Point engineering application. When a wire tower or water well is built, the relevant information related to house demolition can be simulated and deduced in the system according to the set radius, and a thematic map can be generated.
5 Conclusion and experience
This article describes the operation process and operation method of the real estate information to establish the real estate geographic information system, successfully completed the construction of 65 square kilometers, established a "picture management room, picture and text integration" management model, improved the real estate management department business The efficiency of processing also provides a powerful platform for the information construction of the real estate management department, and provides conditions for the real estate business to realize the expansion of cities, counties, towns and villages.
Through the implementation of this work, I realized the following points:
( 1) In the real estate census, you should contact the town and community administrators in a timely manner. With the cooperation of the real estate bureau, land bureau, and planning bureau, you can understand the real housing ownership status and the real situation of the right holders to avoid untrue rights Information to reduce invalid work and rework in investigations.
( 2) The establishment of the GIS system involves many real estate data such as basic maps, mounds, building numbers, layered household maps, house area, household map scans, census table scans, house photos, etc., so the data must first be standardized To define: The main data specifications include: layer [layer name, requirements for the closure of graphics (such as the requirement for closure of the house, etc.)], division of mounds and mounds, and building number coding rules [eg, division of mounds according to main roads Units are divided into the codes of mounds, mounds, and building numbers]. If we formulate these data specifications at the beginning of the construction of the database, it will not only reduce the chance of "rework" and ensure the quality of the data, but also bring a lot of convenience for the future real estate surveying and mapping management.
( 3) The graphic data of real estate surveying and mapping are mainly stored in the form of file storage in each job group and operator's computer, so before establishing the GIS system, these basic data need to be stored in the GIS system in a unified way, so as to ensure the real estate surveying and mapping The data is not heavy or leaky.
( 4) Since the graphic data and the attachment materials are stored separately, it is necessary to ensure the correct association of the data to ensure the accuracy, correspondence and completeness of the data.