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Urban Transfer Entropy across Scales.

Murcio R, Morphet R, Gershenson C, Batty M - PLoS ONE (2015)

Bottom Line: Cities are multidimensional non-linear phenomena, so understanding the relationships and connectivity between scales is important in determining how the interplay of local/regional urban policies may affect the distribution of urban settlements.In order to quantify these relationships, we follow an information theoretic approach using the concept of Transfer Entropy.The results indicate how different policies could affect urban morphology in terms of the information generated across geographical scales.

View Article: PubMed Central - PubMed

Affiliation: Centre for Advanced Spatial Analysis, University College London, London, United Kingdom.

ABSTRACT
The morphology of urban agglomeration is studied here in the context of information exchange between different spatio-temporal scales. Urban migration to and from cities is characterised as non-random and following non-random pathways. Cities are multidimensional non-linear phenomena, so understanding the relationships and connectivity between scales is important in determining how the interplay of local/regional urban policies may affect the distribution of urban settlements. In order to quantify these relationships, we follow an information theoretic approach using the concept of Transfer Entropy. Our analysis is based on a stochastic urban fractal model, which mimics urban growing settlements and migration waves. The results indicate how different policies could affect urban morphology in terms of the information generated across geographical scales.

No MeSH data available.


The London area zoom generated with our urban model for T = 5.0.(A) t4 (B) t5. Source: Black and white structures compiled by authors; Coastline made with Natural Earth. Free vector and raster map data @ naturalearthdata.com.
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pone.0133780.g003: The London area zoom generated with our urban model for T = 5.0.(A) t4 (B) t5. Source: Black and white structures compiled by authors; Coastline made with Natural Earth. Free vector and raster map data @ naturalearthdata.com.

Mentions: For the threshold T = 5.0, representing a moderate urban policy at mark 4, TE values for the regional→local direction are greater than the local→regional until mark 8 (except for mark 6 in which both values are practically equal). At these points, the structure of the information changes in a way that allows the information generated at higher scales to flow to lower ones. From mark 6 this is not that surprising, because we are operating at the higher scales and the information generated at a regional level is mainly responsible for the structures observed at this level. At mark 4 (TE between scales 4 and 5, in both directions) the net direction of the information is indistinguishable in practical terms. This suggests that the regional pattern of information is leading the local but this may simply be the effect of scale with the regional scale identifying as clusters those settlements at a local scale which are growing by accretion. In Fig 3 we show a section from one typical configuration generated for scales 4 and 5, T = 5.0. Although the latter contains a greater proliferation of urban structure, it does not seem to contain more clusters, thereby reinforcing the view that the TE equality reflects growth by accretion and amalgamation with little change in the cluster numbers. The reversal of dominance and the near equality of TEs from thresholds 4.0, 4.5 and 5.0 reflect a change in the distribution of the settlements.


Urban Transfer Entropy across Scales.

Murcio R, Morphet R, Gershenson C, Batty M - PLoS ONE (2015)

The London area zoom generated with our urban model for T = 5.0.(A) t4 (B) t5. Source: Black and white structures compiled by authors; Coastline made with Natural Earth. Free vector and raster map data @ naturalearthdata.com.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4514628&req=5

pone.0133780.g003: The London area zoom generated with our urban model for T = 5.0.(A) t4 (B) t5. Source: Black and white structures compiled by authors; Coastline made with Natural Earth. Free vector and raster map data @ naturalearthdata.com.
Mentions: For the threshold T = 5.0, representing a moderate urban policy at mark 4, TE values for the regional→local direction are greater than the local→regional until mark 8 (except for mark 6 in which both values are practically equal). At these points, the structure of the information changes in a way that allows the information generated at higher scales to flow to lower ones. From mark 6 this is not that surprising, because we are operating at the higher scales and the information generated at a regional level is mainly responsible for the structures observed at this level. At mark 4 (TE between scales 4 and 5, in both directions) the net direction of the information is indistinguishable in practical terms. This suggests that the regional pattern of information is leading the local but this may simply be the effect of scale with the regional scale identifying as clusters those settlements at a local scale which are growing by accretion. In Fig 3 we show a section from one typical configuration generated for scales 4 and 5, T = 5.0. Although the latter contains a greater proliferation of urban structure, it does not seem to contain more clusters, thereby reinforcing the view that the TE equality reflects growth by accretion and amalgamation with little change in the cluster numbers. The reversal of dominance and the near equality of TEs from thresholds 4.0, 4.5 and 5.0 reflect a change in the distribution of the settlements.

Bottom Line: Cities are multidimensional non-linear phenomena, so understanding the relationships and connectivity between scales is important in determining how the interplay of local/regional urban policies may affect the distribution of urban settlements.In order to quantify these relationships, we follow an information theoretic approach using the concept of Transfer Entropy.The results indicate how different policies could affect urban morphology in terms of the information generated across geographical scales.

View Article: PubMed Central - PubMed

Affiliation: Centre for Advanced Spatial Analysis, University College London, London, United Kingdom.

ABSTRACT
The morphology of urban agglomeration is studied here in the context of information exchange between different spatio-temporal scales. Urban migration to and from cities is characterised as non-random and following non-random pathways. Cities are multidimensional non-linear phenomena, so understanding the relationships and connectivity between scales is important in determining how the interplay of local/regional urban policies may affect the distribution of urban settlements. In order to quantify these relationships, we follow an information theoretic approach using the concept of Transfer Entropy. Our analysis is based on a stochastic urban fractal model, which mimics urban growing settlements and migration waves. The results indicate how different policies could affect urban morphology in terms of the information generated across geographical scales.

No MeSH data available.