Ans: Water conservation methods: (1) Rainwater harvesting — collecting roof and land runoff in tanks or recharge wells, replenishing groundwater. (2) Check dams and percolation pits — slow down runoff, allow water to seep into the ground. (3) Drip irrigation — delivers water directly to plant roots, reducing wastage (used in agriculture). (4) Reuse of treated greywater — wastewater from sinks/baths treated and reused for gardening or flushing. (5) Watershed management — treating entire catchment areas to maximize water retention. (6) Traditional systems revival — johads (Rajasthan), surangams (Kerala), kunds, and stepwells. (7) Fixing leaks in pipes and taps. (8) Reducing industrial water wastage through recycling. Conservation helps ensure water availability as groundwater tables are falling in many parts of India.

Ans: Sustainable development means meeting the needs of the present generation without compromising the ability of future generations to meet their own needs (Brundtland Commission, 1987). It balances economic growth, social equity, and environmental protection. How it can be achieved: (1) Use renewable energy sources (solar, wind) instead of fossil fuels. (2) Efficient use of resources — reduce wastage. (3) Conserve forests and biodiversity. (4) Organic farming — reduce pesticide and fertiliser use. (5) Recycling and waste reduction (3R). (6) Green building practices. (7) Environmental education and awareness. (8) Government policies and enforcement of pollution control laws. (9) International cooperation (Paris Agreement, CBD). Sustainable development recognises that economic growth and environmental protection are not opposing goals.

Ans: Advantages: (1) Irrigation — water stored can be used for agriculture year-round, increasing food production. (2) Hydroelectric power — generates clean, renewable electricity for large areas. (3) Flood control — regulates river flow. Disadvantages: (1) Displacement of people — thousands of tribals and villagers lose homes and livelihoods (Sardar Sarovar Dam displaced over 2 lakh people). (2) Loss of biodiversity and forests — large areas submerged destroys habitats. (3) Altered river flow — affects downstream ecosystems, fisheries, and river delta formation. (4) Social inequity — benefits (electricity, irrigation water) often don't reach those most displaced; costs borne by the poor. Famous controversy: Narmada Bachao Andolan protested against Sardar Sarovar Dam.

Ans: Reduce: Use fewer resources — buy only what is needed, avoid wasteful consumption. Buy products with less packaging. Turn off lights and appliances when not in use. Reuse: Use items multiple times before discarding. Reuse glass bottles, bags, containers. Repair items instead of replacing them. Recycle: Convert waste materials into new products. Paper, plastic, glass, metal can be recycled. Reduces the need for raw materials and energy. Benefits: Reduces environmental pollution, conserves natural resources, reduces energy consumption, decreases volume of waste going to landfills, reduces greenhouse gas emissions. Prioritise: Reduce is best → Reuse → Recycle (in decreasing order of environmental benefit).

Ans: IUCN: International Union for Conservation of Nature. It maintains the Red Data Book which lists all endangered species of plants and animals worldwide. It classifies species as: Extinct, Critically endangered, Endangered, Vulnerable, Near threatened, etc. Biodiversity hotspot: A region with exceptionally high biodiversity (large number of species found nowhere else — endemic species) that is also severely threatened by habitat loss and human activity. India has several hotspots: Western Ghats & Sri Lanka, Himalayas, Indo-Burma region, Sundaland. Must have ≥1,500 endemic plant species and have lost ≥70% of its original habitat to qualify.