Sediment capture ponds are widely used to "slow down" water being drained from boreal forests. The main function of the sediment capture ponds is to remove prevent pollution of receiving waters downstream of a forest by removing suspended sediment and associated pollutants.
- Based on Stella definitions, adapted by NWRM project experts and validated by the European Commission
Ditch blocking in managed peatland forests can be used to slow water and trap sediment after forest harvesting. The ditches can be made of wood logs or gabions, for example.
- Elaborated by NWRM project experts and validated by the European Commission
Continuous cover forestry (CCF) is a broad term encompassing a wide variety of forest management practices. One key feature of is that biomass removal is based either on small clearcuts or selective harvesting. Smaller clearcuts may create less hydrological disturbance but some of the filtration benefits associated with forest soils may be lost as a result of the greater driving and road maintenance needed for continuous harvesting.
- Based on Stella definitions, adapted by NWRM project experts and validated by the European Commission
Forest harvesting can cause severe disruptions to the hydrologic cycle. Clearcut areas are often subject to localized flooding due to reductions in evapotranspiration caused by removal of trees. Roads and other infrastructure needed to support forest harvesting can also be significant sources of sediment to surface waters. However, negative effects can be minimized when forest harvesting is performed in a water-sensitive manner and measures are taken to maintain the natural hydrological functioning of the landscape.
Coarse woody debris is a key stream habitat feature used by fish and other organisms. Coarse woody debris can also help to lower flow velocity in streams.
- Based on Stella definitions, adapted by NWRM project experts and validated by the European Commission
A biophysical parameter is a measurable characteristic that can help in defining a particular system. It can cover individual substances, groups of substances or be defined by its measurement method like turbidity or the mesurement of oxygen consumption like BOD5 or COD. It is generally expressed by a value and its unit.
It is widely believed that forest soils can function as pollution filters. Afforestation is practiced in rural areas around many large cities as a means of improving the quality of the drinking water supply aquifer by filtering out pollutants. Afforestation may also reduce peak flows and help to maintain base flows. Such afforestation should reduce sediment loadings and may have other benefits including improved biodiversity and recreational value.
- Based on Stella definitions, adapted by NWRM project experts and validated by the European Commission
Targeted planting of forests in headwater areas (e.g. with a slope) can help to stabilize hillslopes, thereby reducing erosion and potentially leading to greater water retention in montane areas. Afforestation may have beneficial effects on the hydrograph by reducing peak flows and helping to maintain base flows. The potential for water retention must be balanced against the increased ET and pollutant trapping that may be associated with forests.
- Based on Stella definitions, adapted by NWRM project experts and validated by the European Commission
Basins and ponds store surface run-off.ﾠ Detention basins are free from water in dry weather flow conditions but ponds (e.g., retention ponds, flood storage reservoirs, shallow impoundments) contain water in dry weather, and are designed to hold more when it rains.
- Based on Stella definitions, adapted by NWRM project experts and validated by the European Commission
Much of the evapotranspiration from forests falls elsewhere as rain, Ellison et al. (2012), amongst others, have shown that this large scale water pump can be a significant component of the annual precipitation in many continental areas. That is to say, many continental areas would receive a lot less rain if it were not for the mositure returned to the atmosphere by actively growing forests.