Water:
1. Water conservancy engineering and management industry
2. Drinking water and sewage treatment industry
3. Aquaculture and fisheries
4. Tourism and water sports industry
Earth:
1. Construction and civil engineering industries
2. Agriculture and animal husbandry
3. Forestry and wood processing industry
4. Mining and mineral processing industry
Wood:
1. Construction and furniture manufacturing
2. Pulp and paper industry
3. Wood processing and wood products manufacturing
4. Landscape and environmental greening industry
Of course, these are only general classifications, and each industry has more specific and subdivided occupations and work areas.