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GIS & Data Integration
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GIS for Visual Impact Assessment
2.3 User Interface
Many commercial GIS software provides the allowance for developers to customized the user interface according to specific requirements. Following the current software's Window's style, the user interface of the specific GIS for visual
impact assessment should be graphical. However, the gap between the system and public still exits. It comes from the unfamiliarity between public and GIS. That challenges the specific GIS for VIA not only in the system functions but also the user interface and system work style. The latter often contributes more to the public's acceptance for the specific system. In this article, a specific query language, which extends the SQL, is designed to facilitate planners in VIS process The extended SQL is aimed to be in oral style and accompanied by some jargon in VIA, which makes it easy to understand. Its architecture is transferred from standard SELECT-FROM-WHERE form into SELECT-FROM-WHERE-WHAT IF format. The input of query statement can be in text or visual design in customized Java Applet panel. The latter empowers user to interact with spatial objects on the displayed map while accomplishing the query statement. For example, to finish the query on visible area from given viewpoint, user can set up the view point in the WHERE clause by selecting its Id code in the candidate listbox or directly pinpoint it on the map. We map the specific spatial analysis for VIA into meta-operations of the extended SQL. It includes the viewpoint selecting, view shed analysis, and set operations. The user's interaction with themes or spatial objects on the map is also introduced into the SQL statement's formation. For instance, to answer 'what if' questions, system empowers user to do some editing operations on line or polygon objects in the active theme. The result will be included by the WHAT IF clause.
3. Case System
An experimental GIS system has been developed to test the method of integration of both quantitative method and 3D simulation for visual impact assessment by customizing the Arcview 3.1 with spatial analysis and 3D analysis extensions.
Spatial objects stored in the Database Management System (DBMS) are first classified according to their significance in global or local urban landscape. And also main façades of buildings, which contribute more to their scene character, are identified. The categorical system for the features can be listed as below:
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Categorical
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Contents
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Natural landscape Resources
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Natural parks.Community gardens.Recreation facilities
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Humanities landscape resources
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Scenic spot.Shrine and temple
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Public utilities
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Public Office.Schools.Hospitals.Public Hall.Harbours
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Resident Areas
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Residential quarters.Apartment houses
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Public Transportation
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Main local road.National roads.Railway tracks
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Planning project
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Draft of the constructions design.Reshaped Terrain
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4. Preliminary finding and future work:
The experiment GIS system demonstrate the feasibility in the integration of both quantitative analysis and 3D simulation for VIA. It is illustrated by the identical viewpoint in both the two dimensional view for quantitative analysis and the 3D scene for simulation. The comprehensive utilization of set operations for visual impact detection effectively exposes the cumulative visual impacts. However, the system still shows its limitations and should be improved in the future.
- The representation ability of GIS in three dimension for complex scene shows less vivid.
- As mentioned before, VIA characterizes in its public. It is more desired to transfer the whole process from desktop to Internet. Currently, popular web GIS platform shows limit in provide complex analysis service and also lacks in 3D simulation.
- Different from the popular computer aided architecture design software, GIS lacks the flexible toolkits to support design. Some minute edit tool such as changing spatial objects' positions, dimensions can also benefit a lot for quick design prototyping.
Reference:
- Arcview 3D Analyst, 3D Surface Creation, Visualization, and Analysis. Environmental System Research Institute INC( ESRI) .
- Institute of Environmental Assessment and The Landscape Institute (IEATLI), 1995 Guidelines for Landscape and Visual Impact Assessment. First Edition. London: E&FN SPON, and imprint of Chapman&Hall.
- Homma, R., IKI,K., Morozumi, M., and Morisaki, T. 1999. Geographic Information Database for Landscape Evaluation. Proceedings of the Fourth Conference on Computer Aided Architecture Design Research in Asia. Shanghai Scientific and Technological Literature Publishing House.
- JEFF W.T.Kan, BENNY K.M.CHOW, and JIN-YEU,TSOU,1999. Visual Impact evaluation of electricity substation architecture. Proceedings of the Fourth Conference on Computer Aided Architecture Design Research in Asia. Shanghai Scientific and Technological Literature Publishing House.
- Lange, E. 1994 Integration of computerized visual simulation and visual assessment in environmental planning. Landscape and Urban Planning, 30, PP99-112.
- Orland,B.(1992a) Data Visualization Techniques in Envrionmental Management. Landscape and Urban Planning, 21, 237-244.
- Orland, B.(1994) Visualization techniques for incorporation in forest planning geographic information systems. Landscape and Urban Planning, 30,83-97.
- Wherrett, J.R., 1996. Visual Impact Assessment. Visualization Techniques for Landscape Evaluation Literature Review. http://bamboo.mluri.sari.ac.uk/~jo/litrev/chapters.html.
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