11
The Ideal Road Density for Small Islands
S. C. LinDepartment of Construction EngineeringNational Kinmen Institute of Technology
22
The Ideal Road Density for Small Islands
Outlines1. Where and what is Kinmen2. Theory of Biogeography3. Modeling the ideal road density4. The results5. Discussions
33
Taiwan
China
Kinmen
Geographic location of Kinmen
Kinmen !
44Basic Data of Kinmen and Taiwan
KinmenTotal area 150.5 km2
Population 61,215 Area of Main Kinmen Island 134.25 km2
TaiwanTotal area 36,188 km2 Population 22,610,00
Kinmen !
55Road System of Kinmen (1)Road System of Kinmen (1)
Kinmen !
66Road System of Kinmen (2)Road System of Kinmen (2)
Kinmen !
77
Major Road System of Kinmen Major Road System of Kinmen (3)(3)
Kinmen !
88Theory of Island Biogeography
Relation of number of species and area
S = C AZ
S: Number of species
A: Area of the island
MacAurthur & Wilson
Z = 0.24 ~ 0.34
Theory !
99
Relation of number of species and area
S = C AZ
Theory !
ZKM = 0.324 (Kinmen)
Theory of Island Biogeography
324.0
188,36
5.134log
137
22log
KMZ
1010
Density of species for each half = 0.8/0.5 =1.6
Theory !
Theory of Island Biogeography
1111
Road type ConcreteAsphalt Concrete
UnpavedTank
DrivewayTotal
Length 129.9 214.4 18.2 7.3 369.8
Total length of serving roads in Kinmen (unit: km)
Theory !
1212
Population(Thousand)
Area(km2)
Total length of road system
(km)
Number of vehicles
(Thousand)
Vehicle/Total length of roads
Vehicle per capita
Road density
(km/km2)
Kinmen 61 150.5 343.9 13.0 37.8 0.21 2.29
Taiwan[28](Non-metropolitan) 22,610
(overall)
34,818 20,102
6,134(overall)
160.6(overall)
0.27(overall)
0.58
Taiwan(overall)
36,188 38,202 1.06
Okinawa, Japan[23]
1,352 2,271 1,455 552 379.4 0.41 0.64
Netherlands[24] 16,193 33,920 114,427 7,894 69.0 0.49 3.37
USA[25] 292,936 9,372,614 6,297,966 230,428 36.6 0.79 0.67
Roads density in different areas
Theory !
1313
Ideal Road density in continent areas
Studies and field investigations showed that the highest road density wolves can tolerant to maintain their healthy population is ρwolf = 0.6 km/km2
Why?
Theory !
1414
Food web pyramid
Theory !
1515
Ideal Road density for Kinmen
What is the ideal road density for Kinmen ?Three models:1.Direct application of ρ= 0.6 km/km2
2.Model island model3.Largest small island model
Model !
1616
Model island modelTake Okinawa as a model island to KinmenSk is number of species of KinmenSO is number of species of same taxon in OkinawaZ = 0.324
324.0
324.0
O
K
O
K
CA
CA
S
Sn
n = 0.41
Model !
1717
Model island model
O
O
O
O
K
O
K
K
A
S
A
S
A
nS
A
SD 2.6
271,2
15041.0
the density of species in Kinmen D
Model !
1818
Model island model
Unit cell
Roads
LL
L 222
Road Density
Model !
Road Mesh
1919
Model island model
The road density of Okinawa is ρO=0.64 km/km2 that leads to L=3.125 km and the area of the unit cell is then (AO) =L2 = 9.766 km2
To make same species density in Kinmen, enlarging the area of unit cell to 6.2 times for Kinmen’s is necessary.
Model !
2020
Model island model
Therefore the area of Kinmen’s unit cell is(AK) = 6.2 × 9.766 = 60.55 km2. and length of the cell LK = (AK) 1/2 = 7.78 km.
The ideal road density of Kinmen could be obtained as ρKM = 2/LK = 2/7.78 = 0.257 km/km2
Model !
2121
Largest small island model
Take Largest small island as a model island to Kinmen
Largest small islandArea = 1,000 km2 Population = 1,000,000
Follow the same procedure, we haveρKM = 0.316 km/km2
Model !
2222
Ideal Road density for Kinmen ?
Model 1 2 3Kinmen Cu
rrent
Obtained RoaObtained Road Density d Density ρρKM KM
(km/km2)0.60 0.257 0.316 2.290
Results !
2323
Transportation Policy of Kinmen ?Discussions !
2424
Three Principles of Road Construction
1. Avoidance Stop building roads, Remove roads,
Put roads underground, Change the routes
2. Mitigation Make animal corridors, Reduce noises and disturbance,
Use ecological friendly construction materials,
Use cleaner fuel
3. Compensation Create protected areas, Restore destructed habitats,
Enhance habitat conditions
Discussions !
2525
The End