Building-based calculation of parameters on settlement structure using SEMENTA®

Contact

Dr. Gotthard MeinelHead of Research Area

Telefon: + 49 (0)351 46 79 254E-Mail: G.Meinel@ioer.de

Leibniz Institute of Ecological Urban and Regional DevelopmentWeberplatz 101217 Dresden/Germany

Along with the GIS datasets, which can be combined and processed together with own data, an automatic report is generated for all blocks and buildings, providing statistical evaluations of all parameters in the target area. These findings can be further processed using Excel.

This analytical method has been implemented as SettlementAnalyzer (SEMENTA®), a software extension to the widely used mapping platform ArcGIS (ESRI). In the meantime, a further extension allows the building-based analysis of settlement development by the comparative evaluation of maps from different timeframes. The program is continually being refined, and in future will be integrated feature in the Monitor of Settlement and Open Space Development (IOER Monitor) of the Leibniz Institute of Ecological Urban and Regional Development.

Floor area ratio for Dresden-Gorbitz

Research Area

Monitor of Settlement and Open Space Development

• Total footprint: sum of footprints in each block (value in m2).

• Building footprint density: ratio of total footprint to the block area.

• Mean number of floors: weighted mean of the number of floors of all buildings in a block, calculated by taking into account the relative areas of building types.

• Floor area: sum of all building footprints multiplied by the mean number of floors (value in m2).

• Floor area ratio: here, ratio of the floor area to the block area.

• Building volume: the sum of all building volumes in a block (value in m3). Calculated from the footprint areas and regionally differentiated reference values for the number of floors and heights of buildings.

• Building volume density: the ratio of building volume to the block area (value in m³/m²).

• Number of dwellings in block: calculated from building type, footprint areas and number of floors.

• Density of dwelling units: per ha block area• Population in block: calculated from building types,

footprint areas and number of floors. • Population density: per ha block area

Precise knowledge of settlement structures is required for land-use planning and the intelligent design of transport axes and other infrastructural developments at the regional and higher levels. Such data includes not just GIS-based information on the structure of settlements but also parameters on building, population and housing densities. Such information is currently available for only a few cities, and access to data for planning and research purposes is limited.

Today the wide availability of standardised geodata allows the calculation of characteristic parameters on settlement structure. SEMENTA is an innovative tool developed by the Leibniz Institute of Ecological Urban and Regional Development by drawing on its many years of experience in analysing settlement structures in countless target areas and under diverse research constraints.

The method provides a way to calculate settlement parameters of use in spatial planning on the basis of digital or analogue topographical maps of scale 1 : 25,000 (DTK25(-V)), from which information on building footprints is extracted, as well as the Digital Landscape Model (Basis-DLM) of the Official Topographic-Cartographic Information System (ATKIS) (block perimeters and types of use). In this way it is possible to calculate a range of density parameters at high resolution for target areas such as cities, planning regions or Länder.

The total stock of buildings is extracted from the footprint layer of the DTK25(-V) by means of complex image processing. These are then “measured” and classified. Using ATKIS block geometries and the object group “built-up area”, parameters on settlement structure are efficiently and reliably calculated at high resolution (also for large target areas) such as the ratios of various building types, the building footprint density, floor area ratio, building volume density and the density of dwelling units and population for each building block. The method is characterised by:

• its use of inexpensive, regularly updated and exhaustive datasets;

• fully automated calculations; • ease of handling within a GIS environment;• the option of combining and evaluating results with

own GIS data;• the analysis of very large target areas.

SEMENTA calculates the following information automatically as layers in a geographic information system:

• Building type as well as descriptive parameters such as area, width, length, etc.

• The type of every block: 7 types of residential block and 2 types of non-residential block.

• Number of buildings: number of buildings in a block. • Building density: number of buildings per ha block

area.

Building-based calculation of paramenters on settlement structure using SEMENTA®

3D illustration of classified buildings and blocks