Research on Three-dimensional Water Resources Information System Based on ArcGIS
Rong Li, Dongsheng Su, Tao Sun, Jianli Zhang
China Institute of Water Resources and Hydropower Research,
20 West Chegongzhuang Rd.,Beijing 100044,P.R. China
Abstract:
In this paper, the Mengwa flood detention project in Huaihe River Basin is adopted as an example to demonstrate the establishment of GIS database and techniques of COM GIS and 3D visualization. A flood management system of this diversion-detention area is implemented by two steps. Firstly, design and set up a complete 3D scene on the platform of software ArcGlobe in ArcGIS, and then under the environment of Visual Basic, the system is secondarily developed based on object interface of ArcGIS Engine. The system breaks through the limitation of traditional 2D display and realizes various functionality of 3D visualization in the researched area, including 3D display terrain, landform and flood areas, observing from different angle, unbounded zooming, roaming, 3D rotating, querying and so on. The proposed method brings forward a set of practical technological routine for 3D information system development, which can provide decision support of floodwater storage. Furthermore, the approach can be applied into other design, development and application of 3D visualization systems.
1. Introduction
Geographical Information System (GIS) is a frontier branch of science, which integrates Space Science, Survey and Mapping Science, Geography, Information Science, Computer Science, Environmental Science and Management Science. The GIS is not only capable of managing data, text information and graph, but also of integrating and analyzing spatial data from different sources, with diverse formats, structures, projections or resolution levels with the aid of computer, thus it is a new effective technical system in complex processing and analysis of spatial data [1].
Two-dimensional GIS began in the computer aid mapmaking in the 1960’s, and now it has gone deep into every application field. It is essentially based on abstract symbolic system, so it can not provide the original feeling of nature to people, and is difficult to overcome the shortcoming. However, three-dimensional GIS can solve the problem [2]. With the development of Virtual Reality technology, the concept of “digital earth” has been put forward and three-dimensional GIS has become a new technology to promote spatial analysis and expand information representation in GIS. By processing elevation data, three-dimensional GIS can display the landform
and objects in three dimensions to create an obvious scene. This display usage can also meet demand for management, analysis, estimation, decision and visualization [3].
2. System design
2.1 Study area and demand analysis
China has suffered great amounts of disaster and made great deal of losses, including the people’s death, injured and the possession’s loss. Flood is the disaster most frequently occurring every year, and it is more serious in flood season. The flood disaster has become one of the most important factor in restricting the economic construction and continuable development in China. Huaihe River, one of the seven river basins in China, has various degrees of flood disaster happenings for a long time. In order to serve the government for decision-making, the water resources information system has a technical difficulty to be overcome, that is how to exactly show the situation of disasters in a visualized obvious way. It is just about the advantage of three-dimensional GIS, which is good at revealing the phenomenon and dynamic changes in real world by means of three-dimensional graphics and images. As a result, three-dimensional GIS can give a powerful technical support to lay out the three-dimensional scenes of flood area. Nowadays, the most urgent problem for researchers in the work of water resources information system development is to display and analyze the river information in three dimensions.
2.2 Methodology
This system has to show the landform of Mengwa flood diversion-detention area in Huaihe River Basin and construct a series of flood scenes in three dimensions. Based on these landform and geographic data, the system has various basic functionality as well as three-dimensional real-time roaming. In order to implement the functionality, the system has been accomplished by two steps, and different method has been used respectively.
Step 1. Construct a three-dimensional scene using basic geographic data, Digital Elevation Model (DEM) and remote sensing images.
Step 2. Take the Components GIS (COMGIS) as the oriented technology, secondary develop the three-dimensional system to complete the whole functionality.