Urban Planning and Construction Management
Cities are highly concentrated areas of human activities, as well as information and material areas. With the progress of science and technology and the development of economy, the urban system becomes more and more complex, the data and information are more and more, and the service requirements are higher and higher. Urban management is facing new challenges. For the modernization, ecological balance and sustainable development of cities, cities need comprehensive planning. Geographic Information System (GIS) brings new tools to urban planning and management.
In urban management, there are many aspects that can be applied to GIS, such as land, road, pipeline network, environment, population and many other elements can be managed through GIS _. The former focuses on the management of the location, area, ownership and dynamic change of cadastre, while the latter mainly focuses on the management and analysis of power and communication facilities.
The application of GIS in environment, road and so on mentioned below can also be considered as part of the application of GIS in urban management.
Urban construction planning involves many factors, such as land requisition for the development of new towns, demolition and resettlement for the reconstruction of old cities, the matching of infrastructure and public service facilities. In the development and construction activities, if we do not pay attention to the coordination among the various projects, it may cause confusion. The use of GIS to manage various information can effectively prevent the emergence of such confusion, and it is based on this analysis and decision-making. Because of the continuous development of city construction, it is necessary to update the urban basic database at any time, which requires the application of GIS to manage daily urban construction activities in order to ensure the timeliness of information. The application of GIS in daily management of urban construction in Milwaukee is introduced below.
Milwaukee, Wisconsin, USA, began to construct the Urban Geographic Information System in 1976, and has been developing and improving continuously. Because the database is relatively complete, GIS has played a role in many aspects, which can be divided into three main activities.
Milwaukee’s maps are divided into three types：
The first is the cadastral real estate map (locally known as Plot Map), which is compiled by the government tax department. Such maps usually need to be modified and updated in the following circumstances：
The content of land deed changes, including the change of land boundary and the change of land ownership；
In a large plot, it is subdivided into several small plots to produce new land owners；
Widening or connecting of the public roads；
Small plots merge into large ones；
Other changes, such as the change of road name and place and the error correction.
The second is general surveying and mapping (locally known as Quarter-Section Map). This kind of map is compiled by the Municipal Engineering Department of the government. It shows the main land boundary (not as a legal basis), but there are no ordinary buildings. It usually needs to be updated under the following circumstances：
Urban construction causes boundary changes of important objects on the ground；
Re-measure and correct outdated content；
Road opening, widening or closing；
Large plots are consolidated or re-divided；
Change of street name；
Error correction on the map.
The third is land use maps (locally known as Land Use Maps). This map reflects the actual use of land and the main land boundary. Land use maps are compiled by the urban planning department and mainly serve urban planning. They usually need to be updated under the following conditions：
Demolition and reconstruction of houses；
The changing use of houses；
Change of block boundary；
Modification of road names；
Map error correction.
The above three maps are responsible by three independent departments respectively. There are many duplicate contents in the information, and a lot of duplicate work is needed in the updating of maps. After the establishment of the urban geographic information system, the updating of all kinds of information on three maps is clearly distributed to three departments. Three kinds of digital maps are centrally stored in the database to realize data sharing. The content of data modification of each department can be obtained by other departments, which reduces data redundancy and duplication.
Land regionalization management
In the United States, most local governments use land zoning to guide and restrict urban land use and urban development, but there are many differences in specific practices. In Milwaukee, the urban planning department first compiles land use planning, and then formulates zoning after approval. The form of zoning is text and graphics, which is the basis for urban construction and approval of construction applications.
Milwaukee’s land zoning maps are divided into use maps, scope maps and altitude maps, which are used to restrict and regulate conflicting land use, such as prohibiting the construction of large-scale commercial facilities close to major traffic arteries. The scope maps provide for the distance between buildings and the back roads of buildings. The altitude maps specify the height of buildings themselves and the restrictions on interrelationship at altitudes of adjacent buildings.
After using GIS, the three zoning maps can be divided into three layers to manage, and can be overlapped to show and to avoid inconsistencies in data of various departments, in addition, it is convenient to check the errors in the planning map and avoid legal disputes, and it is also convenient for tax authorities to inquire real estate information to adjust the tax on land owners.
Internal Work Management of Architectural Approval Office
Every building must be approved by the competent government department before it is built. Because there are so many applications and it needs on-the-spot investigation, the work is arduous. How to allocate and determine the work of each agent has become a difficult problem in order to fully mobilize everyone’s enthusiasm. After the establishment of Geographic Information System (GIS), application cards for construction projects are recorded in attribute database, in which the building address attributes are associated with the geospatial data, so that it is convenient to display the location distribution of all construction applications in a certain period of time on the map (Fig.), which can conveniently be based on the number of applications, the distance to the city center, and the edge of the survey. The level of demarcation and the scope of responsibility of each staff member have improved the efficiency of work and the internal management of the building approval office.