In Zhejiang province in the southern part of the Yangtze River Delta on the southeast coast of China, the Surveying and Mapping Bureau of Zhejiang contributed to the completion of digital line graphs covering the entire 101,800-square-kilometer province. All together, 17 maps in scales of 1:250000, 330 maps in scales of 1:50000, 4,107 maps in scales of 1:10000, and 226 maps in scales of 1:5000 are now accessible to government departments involved in land development, water conservation, transportation, telecommunications, and other areas.
Surveying and Mapping Bureau of Zhejiang Taking Advantage Of Be In the past, a 250-member project team in the provincial bureau worked on drawing, compiling, and quality inspecting the digital line graphs over a period of nearly five years. Using Bentley solutions enhanced work efficiency, shortening the digital line graph production process by 50 percent and reducing man-hours by almost two-thirds. Instead of requiring about 200 drawing personnel and 30 quality inspectors to produce the whole province’s 1:10000 digital line graphs, the project now requires just 80 drafters and 20 inspectors to finish them.
{sidebar id=234 align=right} “The strong functionality and high efficiency of Bentley software and its use for a variety of mapping and drawing applications significantly increases the productivity of digital map products and can better address the needs of GIS data by all aspects,” said Chen Shaoqin, IT director at Zhejiang Basic Geographic Information Center.
Setting the technological standard for cadastral surveying is one of the major responsibilities of the Zhejiang Bureau of Surveying and Mapping. All digital line graph product drawings must follow China’s basic national scale topographic map regulations. The digital line graphs not only have to compile graphical information, but also collect enough attribute information to meet the potential future needs of GIS applications, keeping factor classification codes in line with national standards.
To comply with national regulations and practical situations, the Zhejiang Bureau of Surveying and Mapping customized the document workspace in MicroStation, including suitable seed documents, resource files, font libraries, color tables, and data dictionaries. Graphics were linked with their attributes using the MDL development tool for tag management. The majority of the graphic properties and attributes were stored in the same document to guarantee easy management and maintenance of files. Attributes of the factor classification codes were managed and maintained through the MicroStation GeoGraphics MSLink keyword function.
Improving topological data quality was also an important goal of the project to ensure that the digital line graphs would satisfy GIS data requirements and be smoothly imported into databases. Bentley software enhanced the digital line graph product quality by providing a stable data format, superior drawing performance, convenient and reliable tag management, and strong topology functions.
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Using the functions provided by MicroStation GeoGraphics and a secondary development interface, the project team performed numerous topological analyses to make certain the topological data would be reliable. Adopting the MDL development language and quality inspection tools enabled high quality of the graphics and attributes.
Achieving efficient resource sharing among the various government departments meant converting data back and forth between DGN and other GIS data formats. The team used the ArcObjects interface for lossless data conversion from MicroStation to geodatabase and FME to convert the spatial data into other GIS formats.
Zhejiang province is one of the provinces enjoying the fastest economic growth in China and its application to GIS technology is leading the GIS industry in China. Through the ability to share digital line graphs in different scales and database with other departments, the Zhejiang Bureau of Surveying and Mapping has significantly contributed to the development of 20-plus departments of government in Zhejiang province, such as irrigation works, traffic, telecommunication, and environmental protection.
