Building and Vegetation Heights 2012

Introduction

The urban structural development of Berlin, with its effects both on the structure of residential and commercial areas and on the distribution and use of non-built-up areas, is shown in various ways on various Environmental Atlas maps:

• 06.01 Actual Use of Built-Up Areas
• 06.02 Inventory of Green and Open Spaces
• 06.07 Urban Structures

The maps on Urban Structural Density (06.09) supplement this information with evaluations of the extent of structural use.

However, all these information items permit only indirect statements to be derived regarding the vertical extent of the natural and artificial structures in the city. This is true in spite of the fact that the Automated Properties Map (ALK), the graphical part of the so-called Register of Properties, provides a cartographic foundation for buildings, is an up-to-date source of information on high-rises, with precise representation of ground space, and including information on numbers of stories. It also permits an approximate derivation of heights in meters above ground level (cf. Figure 1).

Fig. 1: Segment from the Automated Properties Map (ALK; number of storeys in Roman numerals)

Precise and detailed statements on the height and structure of buildings and vegetational areas can be of great significance for various utilization purposes. The usefulness of such a database includes its ability to provide information on:

• complete mapping of greened roofs
• more precise urban climate modelling
• additional differentiation in the mapping of uses in green areas, and
• detailed ascertainment of air and noise pollution in residential areas.

The precision of any modelling of course depends to a large extent on the quality of the input data. For example, in order to permit a detailed calculation of the course of air channels and ventilation conditions, the aerodynamic surface roughness, including its geometrical dimensions, must be known as precisely as possible. Elevated objects, such as buildings or entire blocks of buildings, and also high and dense tree structures, constitute barriers, the effect of which may be to brake the wind even to the point of complete standstill, or else they may have a channelling effect, leading to accelerated wind flows.

With the aid of airborne remote sensing, information on the urban climatic conditions can be derived not only from thermal image procedures, but also indirectly, by means of object-referenced information. The shaping of the urban terrain profile by anthropogenic impervious residential and commercial structures, industrial facilities, and traffic and car-park surfaces, is the key factor here. The types of imperviousness, as well as the building and vegetation structures, have been determined in some detail by means of remote sensing.

The main goal of the present map is the derivation of building heights and the extraction of vegetation height levels for Berlin and the immediate surroundings. An additional goal is the preparation of a geo-database with specific object information, and the provision of this data as a basis for further urban analyses.

All necessary work steps have been undertaken by the Optical Sensing Systems section of the German Aerospace Centre (DLR); they were structured into two project phases. The results of the first phase cover an area of the city of approx. 450 sq km, which, in addition to the entire inner city, includes primarily parts of the southern half of Berlin. The mapping of the rest of the city during the second project phase was also concluded in mid-2014. Due to the different quality of the data, the two areas are to remain separate during the further processing and presentation phases (see also Map Description). The following text is based largely on the Project Report of the first phase.