6. Biogeochemical Cycle
The circulation of nutrients through life (bio) and
through earth (geo) repeatedly (cycle) is a
biogeochemical cycle.
In the other words, the cyclic exchange of nutrient
materials between living organisms and their non-
living environment is called biogeochemical cycle.
The biogeochemical cycles conserve the limited source
of raw material in the environment.
8. HYDROLOGICCYCLE
Hydrologic cycle is the process of transfer of moisture from
the atmosphere to the earth in the form of precipitation,
conveyance of the precipitated water by streams and rivers
to ocean and lakes etc, and evaporation of water back to
the atmosphere.
The main components of Hydrological cycle are-
1. Evaporation 4. Infiltration
2. Transpiration 5. Interception
3. Precipitation 6. Runoff