MacroporesLarge pores in the soil that may form important pathways for infiltration and redistribution of water bypassing the soil matrix as a preferential flow. May result from soil cracking and ped formation, root channels and animal burrows. May be important in transport of contaminants.
MaintenanceFrom the perspective of Natural Water Retention Measures (NWRM), maintenance is the set of actions or processes that are performed to keep an already existing natural process functioning in the best possible manner. Maintenance can include physical activities, the planning process and communication.
Managed Aquifer Recharge (MAR)MAR is the purposeful recharge of water to aquifers for subsequent recovery and environmental benefit. Within the context of urban environment, MAR covers the injection and infiltration of captured stormwater ヨ as such, it is linked to SuDS measures such as rainwater harvesting and infiltration techniques, but worth differentiating as a case where the primary purpose is to increase recharge to aquifers in addition to attenuating surface runoff,Mechanisms used to undertake the recharge should be highlighted. In this respect one can envisage:(i) surface structures to facilitate/augment recharge (such as soakways and infiltration basins);(ii) subsurface indirect recharge - artificial recharge is undertaken through wells drilled within the unsaturated zone;(iii) subsurface direct recharge - artificial recharge is undertaken through wells reaching the saturated zone.The regulatory approach to be adopted for each of the above three mechanisms could differ considerably, due to the fact that the level of natural protection to groundwater is vastly different for each of the mechanisms. - Based on Stella definitions, adapted by NWRM project experts and validated by the European Commission
Meadows and pasturesMeadows are areas or fields whose main vegetation is grass, or other non-woody plants, used for mowing and haying.ᅠ Pastures are grassed or wooded areas, moorland or heathland, generally used for grazing. Due to their rooted soils and their permanent cover, meadows and pastures provide good conditions for the uptake and storage of water during temporary floods. They also protect water quality by trapping sediments and assimilating nutrients. - Based on Stella definitions, adapted by NWRM project experts and validated by the European Commission
MulchingA mulch is a layer of material applied to the surface of an area of soil. Its purpose is any or all of the following:·       to conserve moisture·       to improve the fertility and health of the soil·       to reduce weed growth·       to enhance the visual appeal of the areaMulching as NWRM is using organic material (e.g. bark, wood chips, grape pulp, shell nuts, green waste, leftover crops, compost, manure, straw, dry grass, leaves etc.) to cover the surface of the soil. It may be applied to bare soil, or around existing plants. Mulches of manure or compost will be incorporated naturally into the soil by the activity of worms and other organisms. The process is used both in commercial crop production and in gardening, and when applied correctly can dramatically improve the capacity of soil to store water.
Multiplier effectFactor of proportionality that shows how much spending in a NWRM may induce direct or indirect changes in macroeconomic variables, such as income, employment, investment, etc. It is another way of referring to wider economic impacts of NWRM.