flood protection: 23 phrases in 12 subjects |
Agriculture | 1 |
Bridge construction | 2 |
Construction | 2 |
Ecology | 3 |
Electronics | 3 |
Hydraulic engineering | 1 |
Hydrology | 1 |
Makarov | 2 |
Natural resourses and wildlife conservation | 3 |
Navigation | 1 |
Oceanography & oceanology | 1 |
Technology | 3 |