Groundwater recharge
- Slovak term: Slovenský termín
- Groundwater recharge should be defined as the downward flow of water reaching the water table and replenishing groundwater resources (WHO 2006).
Explanation
It is important to distinguish between infiltration of precipitation and groundwater recharge. When rain falls, some infiltrates into the soil. Much of this moisture is taken up by the roots of plants and is subject to evapotranspiration from the soil zone, and some becomes interflow drainage to streams and rivers. Only a part of the infiltration becomes recharge and moves deeper into the subsurface under gravity, and in arid and semi-arid areas this may be a very small proportion indeed (WHO 2006).
Example
Now that the hydrological cycle has been interfered with as a result of human activities, recharge can also be derived from canals, reservoirs, irrigated land, water mains and sewerage systems in urban areas, mining waste, sewage lagoons -in fact - any artificial water body that is in connection with the subsurface. Artificial recharge, which is becoming an increasingly important resource management option, can also introduce water of different origin and quality into aquifers. This of course means that groundwater recharge is not always of the same good quality as infiltrating rainfall, which itself may be contaminated by acid rain or atmospheric acid deposition (WHO 2006).
References
- WHO (2006) Protecting groundwater for health.
