Universityof Perugia<br />Department of Man and Territory<br />Unit of Rural Landscape Planning<br />Spatio-temporal analy...
2<br />Landscape gradients<br />Landscapes can be viewed as continua and spatial gradients<br />Urbanization can be consid...
3<br />Analysis of urbanization<br />An effective method to analyze the effects of urbanization on ecosystems is to study ...
1<br />1<br />2<br />2<br />3<br />3<br />4<br />4<br />5<br />5<br />6<br />6<br />7<br />7<br />Traditional methods for ...
The approach proposed in this study<br />Comparison of landscape metrics calculated at the samefunctional position along t...
Key steps of methodology<br />Urban-rural gradient modelling based on density estimation of settlements<br />Subsequent la...
Land use data processing<br />LU data was retrieved at a scale of 1:10 000 for the years 1977 and 2000.<br />Extensive pro...
9<br />Built-up data cleaning<br />
10<br />Kernel Density Estimation (KDE)<br />In KDE a moving window (kernel) function is superimposed over a grid of locat...
KDE application<br />The calculated spatial index (SDI – Settlement Density Index) expresses settlement concentration as t...
∆SDI - Urbanization gradient modifications<br />
Landscape subdivision<br />Five urban zones have been defined, each one characterized by a specific SDI interval<br />Desp...
Zone shifting and area variations<br />30000<br />25000<br />20000<br />1977<br />15000<br />2000<br />10000<br />5000<br ...
Reti ecologiche e Greenways  •  Marco Vizzari<br />Landscape metrics<br />Algorithms that quantify specific characteristic...
Metrics calculation<br />Was executed using FRAGSTATS (McGarigal et al., 2002):<br />On the entire landscape and through a...
Main LCLU changes<br />+21%<br />+16%<br />-52%<br />-6%<br />+4%<br />Increase in built-up areas<br />Conversion of sowab...
Metrics at class level for the whole area<br />18<br />
Metrics at landscape level along the 5 zones<br />19<br />YEAR<br />
PLAND at class level along the gradient<br />20<br />
PD at class level along the gradient<br />21<br />
MPS at class level along the gradient<br />22<br />
LSI at class level along the gradient<br />23<br />
Specific zone transformations<br />Higher density urban areas (z1) continue to be dominated by aggregated and branched bui...
Key landscape issues of Perugia<br />Consistent irregular expansion of built-up areas generating erosion and fragmentation...
Concluding remarks<br />Effectiveness of the combined method of gradient analysis and landscape metrics for interpreting t...
I paesaggi periurbani del Perugino: analisi delle trasformazioni dei gradienti insediativi e dell’uso del suolo  – Marco V...
Spatio-temporal analysis using urban-rural gradient modelling and landscape metrics
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Spatio-temporal analysis using urban-rural gradient modelling and landscape metrics

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Spatio-temporal analysis using urban-rural gradient modelling and landscape metrics
Marco Vizzari - Department of Man and Territory, University of Perugia

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Spatio-temporal analysis using urban-rural gradient modelling and landscape metrics

  1. 1. Universityof Perugia<br />Department of Man and Territory<br />Unit of Rural Landscape Planning<br />Spatio-temporal analysis using urban-rural gradient modelling and landscape metrics<br />Marco Vizzari<br />
  2. 2. 2<br />Landscape gradients<br />Landscapes can be viewed as continua and spatial gradients<br />Urbanization can be considered as a particular environmental gradient<br />Along this gradient, urban-rural fringes represent spaces with fuzzy boundaries<br />
  3. 3. 3<br />Analysis of urbanization<br />An effective method to analyze the effects of urbanization on ecosystems is to study their patternsand processes along the urban to rural gradient<br />The quantification of spatial heterogeneity is necessary to explore relationships between ecological processes and spatial patterns<br />A great variety of metrics for the analysis of landscape structure were developed<br />
  4. 4. 1<br />1<br />2<br />2<br />3<br />3<br />4<br />4<br />5<br />5<br />6<br />6<br />7<br />7<br />Traditional methods for ecological gradient analysis<br />The transect method was widely used for urban-rural gradient analysis also for spatio-temporal pattern analysis<br />It is based on the comparison of multi-temporal data spatially coincident, but often functionally and ecologically incomparable<br />
  5. 5. The approach proposed in this study<br />Comparison of landscape metrics calculated at the samefunctional position along the gradient and consequently referred to different spatial extents.<br />4<br />4<br />3<br />3<br />2<br />2<br />1<br />1<br /><ul><li>Objective: investigation of spatio-temporal changes induced by urbanization and other anthropogenic factors</li></li></ul><li>6<br />Study area<br />Umbrian municipalities of Perugia, Corciano, Torgiano and Derutawhich encompass an urban and productive tissue of high territorial continuity around the city of Perugia<br />During the period under investigation (1977-2000) the area is characterized by high urbanization rate and relevant rural transformations<br />
  6. 6. Key steps of methodology<br />Urban-rural gradient modelling based on density estimation of settlements<br />Subsequent landscape subdivision and metrics calculation<br />
  7. 7. Land use data processing<br />LU data was retrieved at a scale of 1:10 000 for the years 1977 and 2000.<br />Extensive processing of built-up data based on morphological analysis methods aimed at segmenting binary patterns of settlements into mutually exclusive categories (Soille and Vogt, 2009)<br />
  8. 8. 9<br />Built-up data cleaning<br />
  9. 9. 10<br />Kernel Density Estimation (KDE)<br />In KDE a moving window (kernel) function is superimposed over a grid of locations and the (distance-weighted) density of point events is estimated at each location, with the degree of smoothing controlled by the kernel bandwidth<br />Bandwidth definition represents the most problematic step, but also the most interesting for exploratory purposes (Jones et al., 1996, Borruso, 2008)<br />
  10. 10. KDE application<br />The calculated spatial index (SDI – Settlement Density Index) expresses settlement concentration as the km2 of surface occupied by settlements over the km2 of the territorial surface.<br />
  11. 11. ∆SDI - Urbanization gradient modifications<br />
  12. 12. Landscape subdivision<br />Five urban zones have been defined, each one characterized by a specific SDI interval<br />Despite their different spatial configuration these contexts were considered ecologically comparable.<br />
  13. 13. Zone shifting and area variations<br />30000<br />25000<br />20000<br />1977<br />15000<br />2000<br />10000<br />5000<br />0<br />z1<br />z2<br />z3<br />z4<br />z5<br />Spatial shifting of the five landscape zones (z1 – z5) along a hypothetical section of the urban-rural gradient and consequent boundaries modifications<br />Settlement Density<br />
  14. 14. Reti ecologiche e Greenways • Marco Vizzari<br />Landscape metrics<br />Algorithms that quantify specific characteristics of patches, classes of patches, or the entire landscape mosaic.<br />Fall into two general categories (McGarigal and Marks 1995, Gustafson 1998): <br />Landscape composition (no reference to spatial attributes)<br />Landscape configuration, requiring spatial information for their calculation<br />
  15. 15. Metrics calculation<br />Was executed using FRAGSTATS (McGarigal et al., 2002):<br />On the entire landscape and through all of the five SDI zones<br />At landscape and at class level<br />For the two periods in analysis<br />
  16. 16. Main LCLU changes<br />+21%<br />+16%<br />-52%<br />-6%<br />+4%<br />Increase in built-up areas<br />Conversion of sowable lands with trees into ordinary sowable lands<br />Decrease in vineyards in favour of sowable lands<br />Decrease in olive groves<br />Expansion of woodlands<br />17<br />
  17. 17. Metrics at class level for the whole area<br />18<br />
  18. 18. Metrics at landscape level along the 5 zones<br />19<br />YEAR<br />
  19. 19. PLAND at class level along the gradient<br />20<br />
  20. 20. PD at class level along the gradient<br />21<br />
  21. 21. MPS at class level along the gradient<br />22<br />
  22. 22. LSI at class level along the gradient<br />23<br />
  23. 23. Specific zone transformations<br />Higher density urban areas (z1) continue to be dominated by aggregated and branched built-up patches<br />Urban fringes (z2), along the gradient, remain the most fragmented and the most vulnerable<br />Outer areas (z3 and z4) continue to be dominated by agricultural land uses, but progressively become more homogeneous<br />Zone 4 is characterized by many fragmented natural and semi-natural elements that increased<br />In zone 5 occurred a moderate expansion of wooded areas<br />24<br />
  24. 24. Key landscape issues of Perugia<br />Consistent irregular expansion of built-up areas generating erosion and fragmentation of traditional periurban agricultural land uses <br />Progressive simplification of the agricultural systems<br />Periurban erosion induced by urbanization, together with simplification of rural land uses, resulted in a consequential loss of landscape diversity along the entire gradient<br />Clear alteration of the characteristics of the typical Umbrian gradients<br />25<br />
  25. 25. Concluding remarks<br />Effectiveness of the combined method of gradient analysis and landscape metrics for interpreting the transformations<br />The settlement density index (SDI), calculated using KDE, allowed the modelling of the urbanization gradient<br />Metrics calculated on the SDI zones showed the structural transformation of landscapes along the gradient<br />Possible improvements:<br />Enhance GIS modelling of urban-rural gradient, but not necessarily!<br />Improve the directionality to the analysis<br />Integrate updated LULC and socio-economic data<br />26<br />
  26. 26. I paesaggi periurbani del Perugino: analisi delle trasformazioni dei gradienti insediativi e dell’uso del suolo – Marco Vizzari<br />27<br />Anyway.. Perugia (still!) remains beautiful!Thankyou!!!<br />Universityof Perugia<br />Department of Man and Territory<br />Unit of Rural Landscape Planning<br />Marco Vizzari<br />vizzari@unipg.it<br />

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