Estimation of flood land use/land cover mapping by regional modelling of flood hazard at sub-basin level case study: Marand basin

Figures & data

Figure 1 Case study area. Source: Author

Figure 2 Map of the LULC classification of the studied area. Source: Author

Figure 3 Map of soil hydrological groups of the studied area. Source: Author

Figure 4 Map of the DEM classes. Source: Author

Figure 5 Slope. Source: Author

Table 1. Maximum rainfall intensity of 1 hour.

Longitude	Latitude	Elevation(m)	Max rainfall intensity(mm)	Station name
45.61	38.93	712	13.24	Jolfa
45.76	38.41	1375	12.54	Marand
46.63	38.5	1675	19.45	Varzaghan
45.7	38.16	1440	12.44	Shabestar

Table 2. Runoff coefficients determination.

	Soil Group A			Soil Group B			Soil Group C			Soil Group D
LULC	Slope (percent)			Slope (percent)			Slope (percent)			Slope (percent)
	<2%	%6-2	%6<	<2%<	%6-2	%6<	<2%	%6-2	%6<	<2%	%6-2	%6<
Built surface	0.65	0.67	0.69	0.66	0.68	0.70	0.68	0.70	0.72	0.69	0.72	0.75
Plantation	0.14	0.18	0.22	0.16	0.21	0.28	0.2	0.25	0.34	0.24	0.29	0.41
Garden	0.08	0.11	0.14	0.1	0.14	0.18	0.12	0.16	0.2	0.15	0.2	0.25
Poor Rangeland & Salt-mersh	0.15	0.25	0.37	0.23	0.34	0.45	0.30	0.42	0.52	0.37	0.50	0.62
Rich Rangeland	0.14	0.22	0.30	0.2	0.28	0.37	0.26	0.35	0.44	0.30	0.40	0.50

Figure 6 LULC risk level assessment flowchart.

Figure 7 Map of the case study sub-basins. Source: Author

Figure 8 The area runoff coefficient map. Source: Author

Figure 9 Runoff coefficient of each sub-basin. Source: Author

Table 3. The peak runoff.

Sub-basin	Runoff (m^3/s)	Sub-basin	Runoff (m^3/s)	Sub-basin	Runoff (m^3/s)
1	67.01	21	55.55	41	76.26
2	89.1	22	58.82	42	35.61
3	53.61	23	49.59	43	37.48
4	91.1	24	23.95	44	27.82
5	68.95	25	35.18	45	71.19
6	41.21	26	53.30	46	85.12
7	56.64	27	47.60	47	68.3
8	47.96	28	12.45	48	98.36
9	51.35	29	101.15	49	18.43
10	100.03	30	62.16	50	26.38
11	89.36	31	42.71	51	62.97
12	21.77	32	82.89	52	31.93
13	56.18	33	42.27	53	69.18
14	68.78	34	53.49	54	27.89
15	43.39	35	42.93	55	43.78
16	80.20	36	121.07	56	66.6
17	36.97	37	56.86	57	69.92
18	76.31	38	45.23	58	71.47
19	18.86	39	102.44
20	42.17	40	101.52

Figure 10 The fuzzy map of DEM. Source: Author

Figure 11 The fuzzy map of peak runoff. Source: Author

Figure 12 Flood hazard map. Source: Author

Figure 13 Map of the marked points with GPS devise. Source: Author

Table 4. Confusion matrix estimating the accuracy of hazard maps.

Risk classes	Very high	High	Medium	Low	Safe	Total	Accuracy (%)
Very high	10	0	0	0	0	10	100
High	0	19	5	0	0	24	79.16
Medium	0	0	12	3	0	15	80
Low	0	0	0	4	1	5	80
Safe	0	0	0	0	5	5	100
total	10	19	17	5	5	59	87.83

Table 5. Area of each LULC in flood risk classes.

LULC	Very high	High	Medium	Low	Safe
Garden	10.85	38.65	55.5	45.16	13.02
Plantetion	58.92	153.8	200.63	104.36	23.51
Built surface	2.92	14.32	20.58	11.41	2.03
Water surface	0.06	0.25	0.39	0.078	0
Rich rangeland	49.55	136.46	239.11	289.52	142.44
Poor rangeland	53.55	127.89	123.33	84.51	11.4
Salt-mersh	1.32	4.44	6.12	3.9	0.02
Total	177.17	475.81	645.66	538.94	192.42

Table 6. Area of high and very high risk categories of LULC.

LULC	Garden	Plantation	Built	Rich Rangeland	Poor Rangeland	Salt -mersh
Area(km^2)	49.5	74.3	17.3	186.01	181.44	5.76