Impact of policy on urban growth

Gargi ChaudhuriPostdoctoral Fellow

Resilience and Adaptive Management GroupUniversity of Alaska Anchorage

AAG Annual Meeting 2012: SLEUTH Symposium

Background• Simulate policy effects on urban growth via CA

model

• Border represents a transitional zone, a region of flow and connection between two socio-economic systems

• Policy is broadly defined as the combination of the political decisions, political history and situations which have directly affected the land use and socio-economic activities on the both sides of the border

• Policy makers are the land managers and political leaders who affect how land is used at this very local level (Reid et al. 2006)Background Objectives Study Area Methodology Data Results Conclusion

Objective•To find out the impact of policy on the

pattern of urban growth in a trans-border region

Courtesy: http://www.eea.europa.eu/articles/analysing-and-managing-urban-growth

Gorizia, Italy and Nova Gorica, Slovenia

4

4

Italy Slovenia

Gori

zia,

Italy

an

d N

ova G

ori

ca,

Slo

venia

Italy

Slovenia

Inte

rnat

iona

l Bor

der

Inte

rnati

onal B

ord

er

Source: Google Maps

Nova Gorica, SLOVENIA

Gorizia, ITALY

Historical Background• Initially under the Austro-Hungarian empire• 1915: Taken over by Italy • 1943 – 1945: Taken over by Germany • Completely destroyed and rebuilt during World War II• 1945 – 1947: Acquired by Yugoslavia• 1947: Old city of Gorizia was divided and western part of

the city went back to Italy and eastern portion remained in

Yugoslavia (Nova Gorica)• 1992: Became part of Slovenia after partition of Yugoslavia.• 2004: Slovenia became part of EU • Spatial Development Strategy of Slovenia (2004)

implemented to foster agglomerated growth of the region • 2007: Became part of Eurozone

SLEUTH

Dat

a: S

cen

ario

11985 1991 1999 20041969 1998

S

L

E

U

T

H

Non-Weighted Roads

Weighted Roads

Dat

a: S

cen

ario

2

Non-Weighted Roads

Weighted Roads

1985 1991 1999 20041969 1998

S

L

E

U

T

H

Dat

a: S

cen

ario

3

1985 1991 1999 20041969 1998

S

L

E

U

T

H

Non-Weighted Roads

Weighted Roads

11

Sc 1

Sc 2

Sc 3

2040 Predicted Images 2040 Predicted Images with Weighted Road

data

2040 Predicted Images with Non-weighted Road data

14

Non-weighted roadWeighted road

Scenario 1

Non-weighted road

Weighted road

Scenario 2

Scenario 3

Weighted road

Non-weighted road

15

• Kappa coefficient• Map comparison technique which is computed from a

confusion matrix derived from cell-by-cell comparison of the observed map and the predicted map

• Kappa = khisto * kloc• khisto

• similarity of the quantitative results, based upon the total number of cells taken in by each class

• kloc• compares the actual success space to the expected

success rate relative to the maximum success space given that the total number of cells of each category does not change

• < 0.00 = poor; 0.00 – 0.20 = slight; 0.21 – 0.40 = fair; 0.41 – 0.60 = moderate; 0.61 – 0.80 = substantial; 0.81 – 1.00 = almost perfect. (Landis and Koch, 1977)

Validation

Spatial Metrics• Number of patches determines the level of fragmentation

• Perimeter-area fractal dimension (PAFRAC) determines the complexity of patch shape (1≤PAFRAC≤2)

• The contagion index is an overall measure of the extent to which the landscape patches are dispersed or clumped

Conclusion• At the local level there are no significant differences

between urban growth with weighted roads and non-weighted roads

• Scenario 3 is more accurate than Scenario 2 and 1

• Nova Gorica still retains its dispersed urban growth pattern

• Scenario 2 and 1 have almost same level of accuracy

• Overall, the territorial cohesion hasn’t affected the urban growth of both the cities

• EU and local integration policies haven’t been successful in fostering an integrated regional growth of the region

17

Thank you!!

University of California Transportation Center (UCTC) Dissertation Research

Grant

Dr. Andrea Faverratti, University of Trieste

Dr. Federico Martellozzo, McGill University

Acknowledgements