Identification of natural hazards and classification of urban areas by TOPSIS model (case study: Bandar Abbas city, Iran)

Figures & data

Figure 1. The study area location in Iran and the three region positions (IRS-1D-Pan, July 2002).

Figure 2. The designed analytical hierarchical structure (AHP).

Table 1. Experience of an earthquake in Bandar Abbas city.

Date of the event	Intensity of earthquake (Richter)	Longitude	Latitude	Reference	Earthquake epicentre
4.10.1622	More than 4	–	–	Itinerary	Bandar Abbas and Hormoz strait
1902	6.4	–	–	–	Bandar Abbas
23.10.1907	6	56.28	27.11	Seismograph center of USA, Los Angeles	Bandar Abbas
24.4.1949	6.1	56.46	27.28	Seismograph center of Philippines Ambolong	Bandar Abbas (Nakhoda Nakhl)
5.7.1949	5.5	56.2	27.2	–	Bandar Abbas
5.8.1949		56.2	27.2	–	Bandar Abbas
7.3.1975	5.9	56.2	27.2	Geophysics Institute of Tehran University	Bandar Abbas (Sarkhon)
17.4.1977	4.6	56.436	27.222	Seismology International Centre of England	Bandar Abbas
21.3.1977	6.2	56.2	27.2	Seismology International Centre of England	Bandar Abbas (khorgoo)
21.8.1993	4.2	56.139	27.212	Seismology International Centre of England	Bandar Abbas
17.2.1997	3.8	56.1	27.169	Seismology International Centre of England	Bandar Abbas
11.2005	5.9	56.2	27.1	Geophysics Institute of Tehran University	Qeshm
11.9.2008	6.1	56.1	27.1	Geophysics Institute of Tehran University	Bandar Abbas (Gachin)

Source: BHRC 1993, 1994, Hormozgan Organization of Management and Planning 2005.

Table 2. Calculation of flood flow rate.

Name of place	Run-off height (mm)	peak discharge (m/s)
Nakhl nakhoda basin	35.72	43.39
Shilat basin	27.89	19.92
Goorsoozan basin	21.11	9.15
Talsiah1 basin	21.11	46.1
Talsiah2 basin	20.15	49.58

Source: Iran University of Science and Technology 1999.

Table 3. Decision-making matrix.

Code	Hazard type and units	Municipal region 1	Municipal region 2	Municipal region 3
A	Earthquake frequency	13	13	13
B	Distance from the earthquake epicentre (bipolar technique)	6	6	9
C	Flood (m^3/s)	49.58	55.25	63.31
D	Talus creep (m)	500	1000	400
E	Landslide (%)	3	3.5	3
F	The number of fault	1	1	2
G	Land subsidence frequency	11	14	13
H	The tide (m)	50	100	250
I	Hurricane and tidal wave (bipolar technique)	9	6	3
J	Dust storms with external source (daily)	30	30	30
K	Wind erosion (ton/hectare/year)	48	25	35
L	Sea level fluctuations (m)	50	100	250

Table 4. Relative weight of parameters.

Hazard type	Relative weight
Earthquake frequency	0.16
Distance from the earthquake epicentre	0.14
Flood	0.14
Talus creep	0.05
Landslide	0.02
The number of fault	0.12
Land subsidence	0.09
The tide	0.04
Hurricane and tidal wave	0.04
Dust storms with external source	0.08
Wind erosion	0.08
Sea level fluctuations	0.04
Total	1

Table 5. Dimensionless matrix.

Code	Region 1	Region 2	Region 3
A	0.578	0.578	0.578
B	0.85	0.485	0.727
C	0.508	0.566	0.649
D	0.421	0.842	0.337
E	0.545	0.636	0.545
F	0.408	0.408	0.816
G	0.499	0.635	0.590
H	0.183	0.365	0.913
I	0.802	0.535	0.267
J	0.577	0.577	0.577
K	0.745	0.388	0.543
L	0.183	0.365	0.913

Table 6. Value of P_ij and ln(P_ij).

	Region 1		Region 2		Region 3
Acronym of hazard	Pij	ln(Pij)	Pij	ln(Pij)	Pij	ln(Pij)
A	0.333	−1.099	0.333	−1.099	0.333	−1.099
B	0.286	−1.252	0.286	−1.252	0.428	−0.849
C	0.295	−1.221	0.328	−1.115	0.377	−0.976
D	0.263	−1.336	0.526	−0.642	0.211	−1.556
E	0.316	−1.152	0.368	−1.000	0.316	−1.152
F	0.25	−1.386	0.25	−1.386	0.5	−0.693
G	0.224	−1.496	0.286	−1.252	0.265	−1.328
H	0.125	−2.080	0.25	−1.3686	0.625	−0.470
I	0.5	−0.693	0.334	−1.097	0.166	−1.796
J	0.333	−1.099	0.333	−1.099	0.333	−1.099
K	0.597	−0.516	0.232	−1.461	0.324	−1.127
L	0.125	−2.080	0.250	−1.386	0.625	−0.470

Figure 3. The distribution of 12 natural hazards in every region.

Figure 4. Diameter matrix.

Table 7. The value of E_j, D_j, W_j, T_j and W_j′.

Acronym of hazard	Ej	Dj	Wj	Tj	Wj′
A	E1 = 0.999	D1 = 0.001	W1 = 0.001	T1 = 0.16	W1′ = 0.003
B	E2 = 0.982	D2 = 0.018	W2 = 0.025	T2 = 0.14	W2′ = 0.060
C	E3 = 0.995	D3 = 0.005	W3 = 0.007	T3 = 0.14	W3′ = 0.017
D	E4 = 0.926	D4 = 0.074	W4 = 0.102	T4 = 0.05	W4′ = 0.088
E	E5 = 0.997	D5 = 0.003	W5 = 0.004	T5 = 0.02	W5­′ = 0.001
F	E6 = 0.946	D6 = 0.054	W6 = 0.074	T6 = 0.12	W6′ = 0.153
G	E7 = 0.951	D7 = 0.04	W7 = 0.067	T7 = 0.09	W7′ = 0.104
H	E8 = 0.819	D8 = 0.18	W8 = 0.294	T8 = 0.04	W8′ = 0.172
I	E9 = 0.920	D9 = 0.08	W9 = 0.110	T9 = 0.04	W9′ = 0.076
J	E10 = 0.999	D10 = 0.001	W10 = 0.001	T10 = 0.08	W10′ = 0.001
K	E11 = 0.92	D11 = 0.079	W11 = 0.109	T11 = 0.08	W11′ = 0.150
L	E12 = 0.819	D12 = 0.181	W12 = 0.249	T12 = 0.04	W12′ = 0.172

Table 8. Weighted dimensionless matrix.

Region	A	B	C	D	E	F	G	H	I	J	K	L
1	0.0017	0.0291	0.0086	0.0337	0.0005	0.0624	0.0519	0.0315	0.0610	0.0006	0.1118	0.0315
2	0.0017	0.0291	0.0096	0.0741	0.006	0.0624	0.0660	0.0628	0.0407	0.0006	0.0582	0.0628
3	0.0017	0.0437	0.0110	0.0297	0.0005	0.1248	0.0614	0.1570	0.0203	0.0006	0.0815	0.1570

Table 9. Determining (A⁻) and (A ⁺).

	A	B	C	D	E	F	G	H	I	J	K	L
(A^+)	0.0017	0.0291	0.0086	0.0297	0.0005	0.0624	0.0519	0.0315	0.0203	0.0006	0.0582	0.0315
(A^−)	0.0017	0.0437	0.0110	0.0741	0.0006	0.1248	0.0660	0.1570	0.0610	0.0006	0.1118	0.1570

Table 10. The values of (d_i⁻) and (d_i⁺).

(di^−)	(di^+)
(d1^−) = 0.1928	(d1^+) = 0.0677
(d2^−) = 0.1586	(d2^+) = 0.0674
(d3^−) = 0.0676	(d3^+) = 0.1949

Table 11. The values of cl_i⁺ and its ranking.

Ascendant order	Value of (cli^+)
(cl3^+) = 0.0903	(cl1^+) = 0.2574
(cl2^+) = 0.2117	(cl2^+) = 0.2117
(cl1^+) = 0.2574	(cl3^+) = 0.0903

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