Flash Floods Causative Criteria | Wadi Surr | Wadi Zawhi | |||||
Class | Susceptibility Class Ranges and Ratings | Susceptibility Class Score | Class | Susceptibility Class Ranges and Ratings | Susceptibility Class Score | Weight (%) | |
Topographic Wetness Index (TWI) | −7.49 - −4.91 | Very Low | 1 | −7.37 - −4.76 | Very Low | 1 | 4 |
−4.9 - −2.95 | Low | 2 | −4.75 - −2.95 | Low | 2 | ||
−2.94 - −0.37 | Moderate | 3 | −2.94 - −0.56 | Moderate | 3 | ||
−0.36 - 3.25 | High | 4 | −0.55 - 2.84 | High | 4 | ||
3.26 - 18.84 | Very High | 5 | 2.85 - 11.08 | Very High | 5 | ||
Elevation (Meters) | 0 - 291 | Very High | 5 | −2 - 269 | Very High | 5 | 9 |
292 - 542 | High | 4 | 270 - 565 | High | 4 | ||
543 - 851 | Moderate | 3 | 566 - 961 | Moderate | 3 | ||
852 - 1280 | Low | 2 | 962 - 1402 | Low | 2 | ||
1281 - 2291 | Very Low | 1 | 1403 - 2211 | Very Low | 1 | ||
Slope (Degree) | 0 - 6.25 | Very High | 5 | 0 - 4.9 | Very High | 5 | 15 |
6.26 - 13.85 | High | 4 | 4.91 - 12.47 | High | 4 | ||
13.86 - 21.67 | Moderate | 3 | 12.48 - 22.93 | Moderate | 3 | ||
21.68 - 30.15 | Low | 2 | 22.94 - 34.51 | Low | 2 | ||
30.16 - 56.96 | Very Low | 1 | 34.52 - 56.78 | Very Low | 1 | ||
Stream Power Index (SPI) | 0 - 0.5 | Very Low | 1 | 0 - 0.1 | Very Low | 1 | 13 |
0.51 - 2.06 | Low | 2 | 0.11 - 0.36 | Low | 2 | ||
2.07 - 4.45 | Moderate | 3 | 0.37 - 0.76 | Moderate | 3 | ||
4.46 - 8.89 | High | 4 | 0.77 - 1.34 | High | 4 | ||
8.9 - 14.17 | Very High | 5 | 1.35 - 2.47 | Very High | 5 | ||
Terrain Roughness Index (TRI) | 0.11 - 0.34 | Very Low | 1 | 0.11 - 0.31 | Very Low | 1 | 3 |
0.35 - 0.42 | Low | 2 | 0.32 - 0.41 | Low | 2 | ||
0.43 - 0.49 | Moderate | 3 | 0.42 - 0.48 | Moderate | 3 | ||
0.5 - 0.57 | High | 4 | 0.49 - 0.56 | High | 4 | ||
0.58 - 0.83 | Very High | 5 | 0.57 - 0.8 | Very High | 5 | ||
Normalized Difference Vegetation Index (NDVI) | −0.06 - 0.01 | Very High | 5 | −0.07 - −0.01 | Very High | 5 | 7 |
0.02 - 0.03 | High | 4 | 0 - 0.02 | High | 4 | ||
0.04 - 0.06 | Moderate | 3 | 0.03 - 0.04 | Moderate | 3 | ||
0.07 - 0.1 | Low | 2 | 0.05 - 0.06 | Low | 2 | ||
0.11 - 0.31 | Very Low | 1 | 0.07 - 0.14 | Very Low | 1 | ||
Sediment Transport Index (STI) | 0 - 97 | Very Low | 1 | 0 - 73 | Very Low | 1 | 3 |
98 - 420 | Low | 2 | 74 - 277 | Low | 2 | ||
421 - 992 | Moderate | 3 | 278 - 673 | Moderate | 3 | ||
993 - 1789 | High | 4 | 674 - 1201 | High | 4 | ||
1790 - 2749 | Very High | 5 | 1202 - 1683 | Very High | 5 | ||
Stream Order | 1st | Very Low | 1 | 1st | Very Low | 1 | 23 |
2nd | Low | 2 | 2nd | Low | 2 | ||
3rd | Moderate | 3 | 3rd | Moderate | 3 | ||
4th | High | 4 | 4th | High | 4 | ||
5th | Very High | 5 | 5th | Very High | 5 | ||
Flow Accumulation (Pixels) | 0 - 2776 | Very Low | 1 | 0 - 1370 | Very Low | 1 | 13 |
2777 - 9590 | Low | 2 | 1371 - 5022 | Low | 2 | ||
9591 - 27,257 | Moderate | 3 | 5023 - 12,897 | Moderate | 3 | ||
27,258 - 52,999 | High | 4 | 12,898 - 18,831 | High | 4 | ||
53,000 - 64,356 | Very High | 5 | 18,832 - 29,103 | Very High | 5 | ||
Geological Formation | Quaternary Sand, Gravel, and Silt Deposits | Not Suitable | 1 | Quaternary Sand, Gravel, and Silt Deposits | Not Suitable | 1 | 10 |
Atiyah Monzogranite, Alkali-Feldspar Granite | Less Suitable | 2 | Marabat Suite, Atiyah Monzogranite | Less Suitable | 2 | ||
Conglomerate, Siltstone and Silicic Volcaniclastic Rocks | Moderate | 3 | Alkali-Feldspar Granite | Moderate | 3 | ||
Andesitic lavas, Porphyritic Amphibolite and Pyroclastic Rocks | Suitable | 4 | Pyroclastic Rocks | Suitable | 4 | ||
Igneous Intrusive Rocks | High Suitable | 5 | |||||
Total | 100 |