Topics
Climate
14
Ice on rivers, lakes, etc
9
Hydrology
8
Climatology
7
Ice mechanics
6
Temperature
5
Environmental aspects
4
Hydroelectric power plants
4
Dams
3
Freezes (Meteorology)
3
Ice
3
Measurement
3
Stream measurements
2
Economic aspects
1
Economic conditions
1
Economic history
1
Regional economics
1
Social aspects
1
Social conditions
1