Maharashtra HSC Env Ed & Water Security cheat sheet

Ecosystem = biotic community + abiotic environment interacting as a functional unit; energy flows one way, nutrients cycle.

Trophic levels: producers (T1) → herbivores (T2) → carnivores (T3+); only ~10% energy transfers between levels (Lindeman's 10% law).

Ecological pyramid types: number, biomass, energy; the energy pyramid is always upright.

Biodiversity levels: genetic, species, ecosystem; India is a megadiverse country with 4 of 36 global biodiversity hotspots (Himalaya, Indo-Burma, Western Ghats–Sri Lanka, Sundaland/Nicobar).

Hotspot criteria (Myers): ≥1500 endemic vascular plant species and ≥70% of original primary vegetation lost.

Species interactions: mutualism (+/+), commensalism (+/0), parasitism (+/−), competition (−/−), predation (+/−).

Ecological succession: primary (bare substrate, pioneer species) vs secondary (after disturbance, soil intact); hydrarch (wet→dry) and xerarch (dry→wet) series.

IUCN Red List categories in order: Extinct, Extinct in Wild, Critically Endangered, Endangered, Vulnerable, Near Threatened, Least Concern, Data Deficient.

Resource classification: renewable (solar, wind, forest if harvested below regeneration) vs non-renewable (coal, petroleum, minerals); recyclable vs non-recyclable.

Soil erosion by water: sheet → rill → gully; by wind: saltation, suspension, creep. Contour ploughing, terracing, strip cropping and shelter belts are control measures.

Forest cover (India State of Forest Report): India ~21–22% forest cover, Maharashtra roughly 16–17% of geographic area; tree cover counted separately from forest cover.

In-situ conservation = protected areas (national park, wildlife sanctuary, biosphere reserve, sacred grove); ex-situ = zoo, botanical garden, seed/gene bank, cryopreservation.

Energy: commercial (coal, oil, gas, electricity) vs non-commercial (fuelwood, dung, crop residue); India's per-capita commercial energy use is about one-third of the world average.

Renewable options: solar PV, solar thermal, wind, small hydro, biomass, biogas (anaerobic digestion of cattle dung), geothermal, tidal, hydrogen fuel cells.

Sustainable harvest rule: use rate ≤ regeneration rate; for groundwater, extraction ≤ natural recharge plus managed recharge.

Watershed = all land draining to a common outlet; watershed management uses contour bunds, check dams, percolation tanks and afforestation to raise recharge.

Primary air pollutants are emitted directly (CO, SO2, NOx, particulates, hydrocarbons); secondary pollutants form in the atmosphere (ozone, PAN, sulfuric/nitric acid).

PM10 = particles ≤10 µm, PM2.5 ≤2.5 µm; PM2.5 penetrates alveoli. National Ambient Air Quality Standards (NAAQS, 2009) cover 12 pollutants.

Classic air pollution episodes: London smog 1952 (SO2 + particulates, ~4000 deaths), Los Angeles photochemical smog (NOx + VOCs + sunlight → ozone).

Water quality indicators: BOD (oxygen demand of biodegradable organics), COD (chemical oxidisable matter), DO (healthy river ≥4 mg/L), pH 6.5–8.5, coliform for faecal contamination.

Eutrophication sequence: nutrient enrichment (N, P) → algal bloom → oxygen depletion → fish kill; nitrate above 10 mg/L in drinking water causes blue-baby (methaemoglobinaemia).

Noise: dB is logarithmic; a 10 dB rise = 10× intensity. Indian ambient limits for residential areas: 55 dB day, 45 dB night; industrial 75/70; silence zone 50/40.

Waste hierarchy (most to least preferred): prevent → reuse → recycle → recover (energy) → dispose.

Solid Waste Management Rules 2016 mandate source segregation into wet, dry and hazardous; Plastic Waste Rules 2016 set EPR (extended producer responsibility).

Water security = reliable access to adequate quantity and acceptable quality of water for health, livelihoods, ecosystems and production, with acceptable risk.

Global freshwater is ~2.5% of total water; usable (accessible) freshwater is under 1% of total; agriculture takes about 70% of withdrawals.

Falkenmark stress index: <1700 m³/person/year = water stress; <1000 = scarcity; <500 = absolute scarcity.

India's per-capita water availability has fallen from ~5177 m³ (1951) to ~1400–1500 m³/year - stress range; Maharashtra is drier than the national average.

Virtual water = water embedded in a product; water footprint = direct + indirect use. A water-saving decision compares blue, green and grey footprints.

Demand management tools: metering and volumetric tariffs, drip/sprinkler irrigation, crop choice (millets vs sugarcane), leak reduction, recycling of greywater.

Quality limits (BIS 10500): pH 6.5–8.5, TDS 500 mg/L desirable, total hardness 300 mg/L, fluoride 1.0–1.5 mg/L, arsenic 0.01 mg/L, nitrate 45 mg/L.

Rainwater harvesting: rooftop yield (litres) ≈ roof area (m²) × rainfall (mm) × runoff coefficient (0.8–0.9 for concrete).

Maharashtra's major river systems: Godavari (largest, ~50% of state area), Krishna, Tapi, Narmada; west-flowing short rivers (Ulhas, Vaitarna, Savitri) drain to the Arabian Sea.

Godavari tributaries: Purna, Pranhita, Indravati, Manjra, Wainganga, Wardha, Penganga; Krishna tributaries: Bhima, Koyna, Panchganga, Dudhganga.

Major dams: Koyna (Shivsagar, Koyna river), Jayakwadi (Paithan, Godavari), Bhakra is not in Maharashtra; Ujani (Bhima), Bhatsa and Upper Vaitarna (Mumbai supply), Hatnur (Tapi).

Maharashtra has a large share of India's large dams and is a leader in irrigation-by-dam storage, yet a large part of its area is drought-prone (Marathwada, Vidarbha).

Groundwater: Deccan Trap basalt aquifers store water in weathered zones and fractures; hard rock limits yield. Overexploited watersheds are notified for regulation.

Watershed development programmes: DPAP, DDP, IWDP, NWDPRA and the state's Jalyukt Shivar Abhiyan (desilting, check dams, farm ponds, recharge structures).

Inter-basin transfer disputes: Maharashtra's share under Godavari and Krishna water disputes tribunals; Polavaram and Babhali are inter-state issues.

Canal irrigation efficiency is low (~35–40%) due to seepage; drip and sprinkler plus canal lining raise effective use.

Greenhouse gases by contribution to warming: CO2 (highest), CH4 (about 25× CO2 GWP over 100 years), N2O (~298×), fluorinated gases (thousands×).

Enhanced greenhouse effect = rise in atmospheric CO2 from ~280 ppm (pre-industrial) to over 420 ppm, raising global mean temperature.

India's climate commitments under its NDC: reduce emissions intensity of GDP by 45% from 2005 levels by 2030 and reach ~50% non-fossil electric capacity by 2030; net zero pledged for 2070.

Disaster management cycle: mitigation and preparedness (pre-disaster) → response and relief → recovery and rehabilitation (post-disaster).

Hazard vs vulnerability vs risk: Risk = Hazard × Vulnerability × Exposure / Capacity.

Maharashtra hazards: drought (Marathwada), floods (Konkan, Mumbai 2005 and 26/7), cyclones (coastal), landslides (Western Ghats), heat waves (Vidarbha).

Sendai Framework 2015–2030: four priorities, seven global targets; India's DM Act 2005 created NDMA, SDMA and DDMA.

Sustainable development: Brundtland definition (1987) - meeting present needs without compromising future generations; SDGs are 17 goals with 169 targets (2015–2030).

Constitutional basis: Article 48A (state duty to protect environment) and Article 51A(g) (fundamental duty of citizens); Article 21 right to clean environment (judicial interpretation).

Key statutes timeline: Wildlife Protection Act 1972, Water (Prevention and Control of Pollution) Act 1974, Forest Conservation Act 1980, Air Act 1981, Environment Protection Act 1986 (umbrella law after Bhopal 1984).

Later laws: Biological Diversity Act 2002, Scheduled Tribes and Other Traditional Forest Dwellers (Forest Rights) Act 2006, National Green Tribunal Act 2010, Wetlands (Conservation and Management) Rules 2017.

Institutions: MoEFCC (union), CPCB (central pollution control), MPCB (Maharashtra Pollution Control Board), National Biodiversity Authority, State Biodiversity Boards, Forest Department.

Principles: precautionary principle, polluter pays, public trust doctrine, sustainable development - all applied by Indian courts.

Environmental clearance under EIA Notification 2006: Category A (central) vs Category B (state); EIA report, public hearing, expert appraisal committee.

Environmental Impact Assessment steps: screening → scoping → baseline study → impact prediction → mitigation → public consultation → decision → monitoring.

Maharashtra-specific bodies: MPCB (consent to establish/operate), Maharashtra Water Resources Regulatory Authority, Maharashtra Coastal Zone Management Authority.

Environmental ethics positions: anthropocentric (human-centred), biocentric (all life has value), ecocentric (ecosystems have value); deep ecology and Gaia hypothesis extend ecocentrism.

Indian traditions: Chipko movement (1973, Sunderlal Bahuguna, tree hugging), Silent Valley (Kerala), Narmada Bachao Andolan (Medha Patkar), Appiko (Karnataka).

Environmental health: air pollution is linked to respiratory and cardiovascular disease; unsafe water and sanitation cause diarrhoeal disease; lead and mercury cause neurotoxicity.

Occupational and community health indicators: infant mortality rate, life expectancy, DALY (disability-adjusted life year) as a burden-of-disease measure.

Community action tools: eco-clubs, school environment clubs, gram sabha resolutions, joint forest management, water user associations, citizen science (bird counts, water quality testing).

Reduce, reuse, recycle, refuse, rot (5Rs); consumer choices such as avoiding single-use plastic and choosing local seasonal food reduce footprint.

Environmental education aims: awareness, knowledge, attitude, skills, participation (UNESCO Tbilisi 1977 categories).

Equity principle: polluter pays and common but differentiated responsibilities place a greater burden on those who cause more environmental damage.