Maharashtra HSC Env Ed & Water Security key terms

A community of living organisms interacting with one another and with their non-living surroundings, such as soil, water, and air, functioning together as a unit through flows of energy and nutrients.

The variety of life at all levels, including genetic differences within species, the range of species present, and the diversity of ecosystems and the ecological processes that sustain them.

A sequence showing how energy and matter pass from producers such as plants to herbivores and then to successive predators, with decomposers breaking down dead material at every stage.

A diagram representing numbers, biomass, or energy at each feeding level of an ecosystem, usually narrowing towards the top because energy is lost at every transfer between levels.

The position an organism occupies in a food chain, counted from the primary producers, so that plants form the first level, herbivores the second, and carnivores the levels above.

A region with exceptionally high numbers of species found nowhere else combined with severe habitat loss, used to prioritise conservation spending; the Western Ghats is one such global hotspot.

A plant or animal whose natural range is restricted to one defined area and which occurs nowhere else, making it especially vulnerable to local habitat destruction or disturbance.

Development that meets present needs without compromising the ability of future generations to meet their own, balancing economic growth, social equity, and environmental protection in decision-making.

The maximum population or level of use an ecosystem or resource can support indefinitely without degrading the natural capital on which that population or use depends.

A natural resource replenished by natural processes within a human lifetime, such as solar energy, wind, flowing water, and biomass, provided extraction does not exceed the rate of renewal.

A resource formed over geological time, such as coal, petroleum, or minerals, whose stock is effectively fixed and is depleted once extracted and consumed.

Reducing the quantity of energy used to deliver the same service, through efficient appliances, better building design, and avoidance of waste rather than through cutting useful activity.

The detachment and removal of topsoil by wind or flowing water, accelerated by vegetation loss, overgrazing, and steep cultivation, which reduces fertility and silts downstream reservoirs.

A soil and water conservation practice in which earthen ridges are built along the contour of a slope to slow runoff, trap sediment, and increase infiltration into the field.

The addition to air, water, soil, or the acoustic environment of substances, energy, or organisms at concentrations that harm human health, living resources, or the functioning of ecosystems.

Any substance, noise, heat, or radiation introduced into the environment that causes undesirable change, whether it is a gas from combustion, a pesticide residue, or untreated sewage.

The amount of dissolved oxygen consumed by microorganisms while decomposing organic matter in a water sample over a set period, used as an indicator of organic pollution strength.

Nutrient enrichment of a water body, usually by nitrates and phosphates, that triggers excessive algal growth, oxygen depletion on decay, and loss of fish and other aquatic life.

The use of living organisms, commonly bacteria, fungi, or plants, to break down or remove contaminants from soil, water, or air, converting them into less harmful substances.

The organised sequence of collection, transport, segregation, processing, recycling, and safe disposal of discarded material, with segregation at source being the step that determines recovery quality.

Unwanted or excessive sound measured in decibels on a logarithmic scale, capable of causing hearing damage, sleep disturbance, and stress, and regulated by ambient noise standards.

The reliable availability of water of acceptable quality, in sufficient quantity, to support health, livelihoods, ecosystems, and economic activity, together with acceptable levels of water-related risk.

A condition where demand for water approaches or exceeds the supply available in a region, measured by per-capita availability or by the share of renewable supply already withdrawn.

Collection and storage of rain from roofs or catchments for later use, or its deliberate infiltration into the ground, reducing dependence on distant supply and replenishing local aquifers.

The natural or artificial process by which water from rain, rivers, or applied irrigation percolates downward to replenish the saturated zone of an aquifer.

A long-term decline in stored groundwater caused by extraction exceeding natural recharge, lowering water tables, drying shallow wells, and raising pumping costs.

An underground layer of rock or sediment that holds water in its pores and fractures and can transmit it in quantities sufficient to supply wells and springs.

The entire land area that drains to a common outlet such as a river, lake, or dam, bounded by a ridge, within which rainfall, runoff, and land use are hydrologically linked.

Integrated treatment of a catchment through soil conservation, afforestation, check dams, and regulation of land use so that runoff is moderated and water is retained for productive use.

The land surface from which rainfall flows into a particular reservoir, river reach, or drainage point, determining the volume of water that can be expected to arrive there.

A proposal to transfer water from surplus river basins to deficit basins through canals and reservoirs, intended to reduce flood and drought impacts but contested for ecological and social costs.

Long-term shifts in temperature, rainfall, and weather patterns driven mainly by greenhouse gas emissions from burning fossil fuels and by land-use change, with rising sea levels and extreme events.

The warming of the lower atmosphere as certain gases absorb outgoing infrared radiation and re-emit it downwards, a natural process intensified by human emissions of carbon dioxide and methane.

The total greenhouse gases released directly and indirectly by an activity, product, or person, commonly expressed as tonnes of carbon dioxide equivalent per year.

Systematic effort to reduce exposure and vulnerability to hazards and to strengthen coping capacity, through land-use planning, early warning, preparedness, and resilient infrastructure.

The degree to which a community, system, or asset is likely to be harmed by a hazard, shaped by poverty, location, construction quality, access to information, and social protection.

A statutory procedure that evaluates the likely environmental effects of a proposed project or expansion before approval, requires public consultation, and sets conditions for clearance.

The rule that lack of full scientific certainty should not delay cost-effective measures to prevent serious or irreversible environmental harm when a credible threat exists.

The principle that the party causing pollution bears the cost of preventing, controlling, and remediating it, so that environmental costs are reflected in the price of the activity.

The legal idea that the state holds natural resources such as air, water, and coasts in trust for the public and cannot allow them to be used in ways that deny public use.

The study of the moral relationship between humans and the natural world, asking what duties we owe to other species, to future generations, and to ecosystems themselves.

An economic model in which materials are kept in use through reuse, repair, and recycling, so that waste from one process becomes input to another rather than being discarded.