Maharashtra SSC Water Security Grade key terms

The continuous movement of water between the ocean, atmosphere and land through evaporation, transpiration, condensation, precipitation, infiltration, runoff and groundwater flow, with storage in glaciers, soil and aquifers.

The entire area of land from which rain and snowmelt drain through streams and rivers to a single outlet point, bounded by ridges and hills that form its natural drainage divide.

Planned treatment of a catchment using contour trenches, check dams, bunds, afforestation and pasture improvement so that rain is retained and infiltrated locally rather than lost as fast runoff.

The portion of rainfall that does not soak into the soil or evaporate but flows over the land surface into streams, tanks and rivers, carrying soil and dissolved salts with it.

The downward entry of water from the soil surface into the soil profile, governed by soil texture, structure, moisture content, vegetation cover and compaction, and feeding groundwater recharge.

A saturated geological formation of sand, gravel, sandstone or fractured rock that can store and transmit water in usable quantities through wells, borewells and springs.

The upper surface of the saturated zone in an unconfined aquifer, whose depth below ground rises during the monsoon and falls during summer or heavy pumping.

The natural or engineered addition of surface water to an aquifer through infiltration from rainfall, rivers, tanks, recharge pits, shafts or injection wells.

Collection and storage of roof or surface runoff for later use, or its deliberate channelling into the ground, instead of allowing it to drain away as waste.

An earthen embankment built across a small seasonal stream to hold runoff and allow it to seep slowly into the ground, recharging wells and borewells downstream.

A small low-height barrier across a stream or gully that slows flow, reduces soil erosion, stores water for local use and increases infiltration into the streambed and banks.

The combined loss of water to the atmosphere as evaporation from soil and open water surfaces plus transpiration from plant leaves, a major term in any water balance.

An accounting of all water entering and leaving a defined area or storage over a period, balancing rainfall, inflow, storage change, evapotranspiration, runoff and abstraction.

Pumping groundwater faster than it is naturally recharged, causing falling water tables, drying wells, land subsidence and intrusion of saline or polluted water into aquifers.

A prolonged deficit of rainfall and soil moisture relative to the normal for an area, leading to crop failure, depleted reservoirs, falling water tables and drinking-water scarcity.

A sudden, short-duration rise of water in a stream or low-lying area, typically after intense rainfall on saturated or hard surfaces, leaving little time for warning or evacuation.

The accumulation of eroded soil particles on the bed of a reservoir, tank or channel, which steadily reduces its storage capacity and can block outlets and canals.

Detachment and removal of topsoil by raindrop impact, sheet flow, rills, gullies or wind, reducing fertility and causing siltation of tanks, reservoirs and riverbeds downstream.

A condition where available water per person or per use falls below requirements in quantity or quality, caused by low rainfall, high demand, pollution or poor storage and distribution.

The suitability of water for drinking, irrigation, industry or aquatic life, judged by physical, chemical and biological characteristics such as turbidity, pH, hardness, salts and pathogens.

The concentration of dissolved salts and minerals in water, measured in milligrams per litre; high values make water salty, unpalatable and unsuitable for many crops.

The Indian Standards specification for drinking water that sets acceptable and permissible limits for parameters such as pH, turbidity, hardness, nitrate, fluoride, arsenic and coliform bacteria.

A group of bacteria used as an indicator of faecal contamination in water; their presence signals that disease-causing organisms may also be present and that disinfection is needed.

Illness such as cholera, typhoid, dysentery, hepatitis A or diarrhoea spread by drinking or contacting water contaminated with human or animal faeces.

A health condition caused by long-term intake of excessive fluoride in drinking water, producing mottled teeth and, in severe cases, skeletal deformities and joint pain.

Disinfection of water by adding chlorine or bleaching powder to kill disease-causing bacteria, with a residual dose maintained to protect water during storage and distribution.

Safe management of human excreta, wastewater and solid waste through toilets, sewers, septic tanks and treatment, preventing contamination of water sources and soil.

A status declared for a village or area when no household defecates in the open and all have access to and use a safe toilet, supported by behaviour-change follow-up.

The amount of crop yield or economic output produced per unit of water used, raised by better irrigation timing, mulching, deficit irrigation and choice of suitable crops.

Drip and sprinkler methods that deliver water slowly and precisely near plant roots, saving water and improving yields compared with flood irrigation of fields.

The proportion of water delivered for irrigation that is beneficially used by crops, reduced by seepage, evaporation, over-watering and poor scheduling in canals and fields.

Planned combined use of surface water from canals or tanks and groundwater from wells, so that each source supplements the other and aquifers are not depleted.

Involvement of villagers, water user groups and local bodies in planning, building, operating and maintaining water schemes, which improves ownership and sustainability.

An organisation of farmers or households sharing a canal, tank or scheme that manages water distribution, resolves conflicts, collects charges and maintains the common infrastructure.

A public review of a water or sanitation programme by the community itself, checking records, works and spending against what was promised and demanding accountability for gaps.

The laws, policies, institutions, rules and decision processes through which water is allocated, regulated, priced and managed among competing users and levels of government.

Adjustments in water storage, cropping, warning systems and infrastructure to reduce harm from altered rainfall, more intense extremes, higher evaporation and shifting monsoon patterns.