Answering the question what are GIS technologies first GIS have to be defined. In several publication GIS is defined as computer software which links geographic information (where things are, spatial pinpointing) with descriptive information (what things are). In addition or contrast to the traditional mapping philosophy many layers of diverse information can be presented. Real world features are represented as points, lines, and areas and lately also as three dimensional objects.
The representation can be easily directed due to the reason, that each particular theme has its own layer. These layered displayed themes can be laid on top of one another, creating a stack of information about a specific geographic region. This enables the user to control to the amount of information which will be represented at one time. The combination and the relation between the given features can be analysed at the same
time and displayed (Note, according the statement: “A picture says more than a thousand of words”).
The sources for the represented information are databases. The representation is not limited to geometric features like points, lines, areas, 3D elements (vector information) because GIS contains a further opportunity to display raster information like satellite images and aerial photographs as background information. Remotely sensed information is enclosed next to the visible picture the information of the non visible range of light, which can be used for spectral analysis. Thus raster information can be analyzed according to their spectral information content. By additional spectral analysis recognition of surface material is possible. Terrain model can be generated using radar techniques (Shuttle Radar Topographic Mission; SRTM, TerraX-SAR) for a rough representation and more precise with airborne based LIDAR. Raster layer can also be the result of data analysis like terrain modelling, slope analysis, direction analysis or an interpolation algorithm like IDW, Kriging. Spatial analysis and particular map algebra is able to support decision making by creating of cost layers, which can help to find the path with the lowest resistance – lowest cost.
Geography is helping governments and organisations to make better integrated information based decisions in various disciplines. Spatial related data can be congregated and organized to support the generation of information products that are integrated in the business strategy of any organization. Geographic information systems support the creation of useful information, which enables institutions to run better. Due to the kind of data integration, analysis and distribution these information systems are saving time and resources in the organizations. The geographic aspects matters in infrastructure projects and have an impact to the project controlling and projects financial part.
Civil engineers and surveying engineers (surveyors) understand the collection of spatial related features as a major part of their work. Surveying engineers determine the precise location of real world features either for representing the features on a map or they give positions for manmade designed objects in the real world. Engineers design and build structures and infrastructures on features measured by surveyors.
GIS helps both disciplines to integrate a variety of data sources and types, it enables the user to maintain and manage inventories, and give the opportunity for visualizing data and related information on active maps.
For construction of civil projects there is the necessity to understand where geologically the best suited places for structures are. After determining the best places geotechnical engineers will investigate the underground of the intended civil structure in detail. Drill holes or boreholes will give answers to the question which kind of soil (layers) are
involved, on which material the structure will be placed and how deep the foundation has to be placed to get static stability. GIS techniques from the exploration can be used for this task [ARCGISGEOLOGY].
GIS does not end on the shoreline, as one might think. In specialised GIS (Marine GIS) [ARCGISMARINE2003] records from oceanography to hydrography, the coastal shoreline to the bathymetric bottom can the organized and accumulated. As GIS helps to visualize, analyse and to map the topographic features onshore GIS allows as well executing similar tasks for the large regions of the planet which are underwater. The most interesting statements for the construction industry are the mapping of the seafloor and the nautical charts to have a three-dimensional view of their actual position in relation to a new marina construction. The underwater construction progress control might be another opportunity which can be handled in these systems to visualize and report the change during construction time.
GIS usage has exploded across the world with the recent advancements in computer hardware and software. The World Wide Web has also played a vital role in the availability of data for GIS and the distribution of GIS analysis results. Thousands of communities, agencies, companies, and individuals are now using GIS technology for data management and analysis. The purpose is to provide GIS related skills to civil engineers that are discipline specific. The application of GIS technology will help civil engineers to create solutions founded on integrated informed based decisions.
There are three main ideas for using GIS technologies:
- Implementation of GIS technology is occurring around the constructors work and data evaluation and distribution is undertaken in digital form
- Deals with an extremely large amount of data that is geographic related with the focus on a civil infrastructure project
- Representing condensed information in form of maps and uses integrated scientific analysis
To focus on the GIS technologies, which are applicable for the construction industry, a compound will show the scientific disciplines that are involved in or using GIS (see figure 4.0a) and which departments of a construction company are involved in the preparation creation of a civil infrastructure project (see figure 4.0b). The figures should demonstrate the resemblances and differences exist in both configurations. Relations in the configuration are the business (business geographic) on the GIS side and the finance, estimation and procurement on the infrastructure project side. Surveying, geodesy and civil design as well as landscaping can be connected with the navigation,
and the geotechnical investigations, which are influenced by the geo-physical measurements and investigations by the help of geo-statistic analysis. Colours in figure 4.0a and 4.0b give an indication of the parallelism in the structures.
Figure 4.0a Scientific disciplines involved in or using GIS [UNIGIS Module 1 GIS overview, Hesterkamp, changed]
Figure 4.0b Involved construction company departments for civil infrastructure projects [Hesterkamp]
CONTROLING MANAGEMENT MONITORING