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Geo Information System

A number of technical systems and tools have been developed during the first phase of the project METRASYS. These technical systems and tool provide the basis to fulfill and measure the project goal of a sustainable and energy efficient transport system. The technical systems and tools also provide the basis to measure and model selected scenarios. The data base for most activities is a Geographic Information System (GIS). The GIS serves as a central data base to store, process and describe spatial data. It serves as platform for data exchange and as tool to display results. On the page you will find some selected results from the GIS.

City Development

Hefei has undergone an enormous growth since 1949. From 1949 until 1989, Hefei grew to the size of 75.5 sq km, which represents a growth rate of almost 2,000 percent. Over the past 20 years, Hefei has grown to a constructed area of approximately 285 sq km, and the city still continues its growth. The largest constructed area growth was achieved within the last ten years. Since 1999, Hefei grew by roughly 160 sq km, which equals a growth rate of nearly 230 percent.

1949 - 1995

1999 - 2009

 1949 - 2009

Traffic

Along with the development of the whole population and the urban sprawl, the traffic situation in Hefei has also changed in the last 20 years. From 2001 to 2007, the number of registered vehicles in Hefei increased from 136,953 to 330,159. In 2008 there were already 236,643 cars, 168,839 trucks, 52,662 other vehicles and 17,142 motorcycles registered in Hefei. In order to cope with the rapid urban growth and the increasing motorization as well as the subsequent traffic congestion problems, Hefei has concentrated on building an excellent road infrastructure. The road network, for example, grew from 346 km (1990) to 911 km (2005).

The public transport in Hefei is characterized by bus and taxi services. In 2009, the total length of the bus lines was 1840.6 km with an average line length of 16.6 km and an average bus frequency of six minutes. In 2009, altogether 1.7 million passengers were carried by bus daily. This equals a 2.5 times higher number of passengers since 2003. The average bus speed inside the city area and outside the rush hour is 18.27 km/h.

Public Transport System

Road Network & Expressways

Transport Infrastucture

Landuse

For the development of a traffic management system and the dispersion model, it is important to know the city: Where are the housing areas, where are the production areas and so on. METRASYS collected data on the current land use in different ways and methods (e.g. Unsupervised and Supervised Classification, Fuzzy-Classification, Maximum Likelihood). Initially, historic and current planning documents were analyzed, digitalized and incorporated into the GIS. METRASYS also classified land uses on different satellite images (Landsat, SPOT).

Landuse based on Spot Image unsupervised small Landuse based on Spot Image supervised small Landuse TM Definiens small

Unsupervised Classification

 Supervised Classification

Object Based Classification

Emission Model

For the dispersion model, TEAS processes land use data. The data corresponds to the resolution of the calculated grid that is composed of 500 to 500 meter boxes based on specific land use classes purchased SPOT satellite image and the Landsat satellite image of 2006. Five land use classes were distinguished:

Emission-Hefei-Water_small Emission-Hefei-lowVeg_small Emission-Hefei-highVeg_small Emission-Hefei-lowDensity_small Emission-Hefei-highDensity_small

Water

Low Vegetation

High Vegetation

Low Density

 High Density

Elevation Model

For the calculation of the dispersion model available, SRTM and ASTER elevation models of the Anhui Province were integrated into the GIS.

Elevation-Modell_small