S/N | Causal Factors | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | Score | Rank |
1 | Incidence of pollution | 59 | 20 | 6 | 10 | 10 | - | - | - | - | 207 | 1 |
2 | Gas flaring | 31 | 40 | 6 | 18 | 10 | - | - | - | - | 251 | 2 |
3 | Industrial pollution | 10 | 21 | 20 | 31 | 23 | - | - | - | - | 351 | 3 |
4 | Thermal pollution | 5 | 9 | 32 | 36 | 20 | 3 | - | - | - | 368 | 4 |
5 | Erosion | - | 15 | 20 | 10 | 30 | 30 | - | - | - | 460 | 5 |
6 | Siltation | - | - | 11 | - | 20 | 40 | 33 | 1 | - | 612 | 6 |
7 | Physical obstruction of water ways by waste and equipment | - | - | - | - | 2 | 32 | 41 | 20 | 10 | 739 | 7 |
8 | Sewage pollution | - | - | - | - | - | - | 21 | 50 | 34 | 847 | 8 |
9 | Flooding | - | - | - | - | - | - | 10 | 34 | 61 | 891 | 9 |