A Comprehensive View on Urban Spatial Structure: Urban Density Patterns of German City Regions

Angelika Krehl,Michael Wurm,Stefan Siedentop,Hannes Taubenböck

doi:10.3390/ijgi5060076

Abstract

Urban density must be considered a key concept in the description of a city’s urban spatial structure. Countless studies have provided evidence of a close relationship between built density and activity densities, on the one hand, and urban environmental conditions or social practices, on the other hand. However, despite the concept’s common use in urban research, urban density is a rather fuzzy and highly complex concept that is accompanied by a confusing variety of indicators and measurement approaches. To date, an internationally-accepted standard for the implementation of density indicators that permits a robust comparison of different countries, regions or cities is widely missing. This paper discusses the analytical opportunities that recent remote sensing data offer in regard to an objective and transparent measurement of built density patterns of city regions. It furthermore clarifies the interrelations between built and activity densities. We apply our approach to four German city regions to demonstrate the analytical capacity of spatially-refined density indicators for the purposes of comparative urban research at a regional scale. In so doing, we contribute to a more encompassing and robust understanding of the urban density concept when analyzing regional morphology.

Highlights

In urban research and planning, the spatial densification of human activities and their physical manifestation as built density are key factors in describing the form and structure of the built environment [1,2,3,4,5]
With an increase in the built density of a city, the number of trips that are made on foot, by bicycle or public transportation increases, as the average trip distance decreases and the quality of transit services increases, everything else being equal [2,7,11,12]
Our results show that the regions of Cologne and Munich have the highest built densities among all regions included, while the intensity of use in the regions of Frankfurt and Stuttgart is noticeably higher

Summary

Introduction

In urban research and planning, the spatial densification of human activities and their physical manifestation as built density are key factors in describing the form and structure of the built environment [1,2,3,4,5]. With the methodological approach introduced here, it is, for the first time, possible to conduct a region-wide, detailed analysis of the urban spatial structure that considers built densities Previous studies in this field only illustrate urban morphology in a two-dimensional space using socioeconomic and land use data, whereas our approach achieves a higher level of analytic depth. In this way, the relationship between socioeconomic processes and built physical structures can be examined more closely. This article concludes with a short summary regarding potential explanatory factors of urban density patterns (such as topography, urbanization history or economic structures) and future applications of spatially-differentiated density data (Section 6)

Conceptualization of Built Density

Remote Sensing-Based Measurement of Built-Up Volume and the Number of Floors

Findings

Discussion

Conclusions and Outlook