Water Demand and the Hydrological Cycle

Water and Its Importance

• Water is essential for life, renewable, and reusable.
• Approximately three-fourths of the Earth is covered by water.
• Less than 1% of the water on Earth is fresh and usable for living organisms.
• The hydrological cycle involves water circulating between land and sky; solar heat causes evaporation, and plants release water through transpiration.

Factors Increasing Water Demand

• A growing population leads to increased water demand for drinking, sanitation, domestic use, irrigation, and industries.
• Expansion of irrigation leads to increases in water demand, due to seasonal rainfall variations, uncertainty of rainy seasons, the growing demand of water for commercial crops and due to changing crop patterns.

Increasing Demands

• Increased demand by industry, with the largest proportion of water being consumed by thermal power plants.
• Changing lifestyles involving many appliances and fittings which also contribute to raising demand.

Methods of Water Conservation

• Agricultural lands near cities can use municipal wastewater for irrigation.
• Recycling household "grey water" reduces the need for pure water.
• Used bath and shower water can be used for watering plants.
• Water harvesting collects rainwater for later use or to replenish groundwater.
• Groundwater recharge occurs when surface water moves downward into groundwater.

Water Resource Management

• Key strategies involve reducing water loss/wastage and removing pollutants.
• River pollution stems from industrial/urban effluents, bathing, washing, and waste disposal.
• The Government of India has launched Ganga Action Plan (GAP) and Yamuna Action Plan (YAP) to clean up rivers.

Energy and Its Sources

• Energy is the capacity to do work and can be transformed but not created, destroyed, or recycled.
• Energy sources are classified as renewable or non-renewable.
• Society uses energy for cooking, running appliances, transport, pumping water, and industrial processes.
• Conventional energy sources are fossil fuels, which are limited and non-renewable.
• Coal is mined and transported, found in Raniganj, Jharia, and Dhanbad in Bihar.
• Oil is pumped from wells and transported; used in automobiles and airplanes, found along the west coast and in Digboi oil fields, Assam.
• Natural gas includes LPG and CNG, LPG is in cooking cylinders, CNG in public transport. CNG stands for Compressed Natural Gas and LPG stands for Liquified Petroleum Gas.

Alternative Energy Sources

• Due to increased fossil fuel consumption, alternative non-conventional sources are needed.
• Alternative sources consist of Solar, Wind, Hydel, Tidal, Geothermal, and Biomass energy.
• Conventional energy uses have been practiced for a long time.
• Non-conventional sources of energy are not used frequently and in large scale, and their uses are more recent.
• Most conventional energy besides hydel power is costly, but non-conventional energy is cheaper.
• Solar energy harvested through "solar panels" is widespread, non-polluting, and free.
• Wind turbines rotate magnets to create electricity.
• Many dams store water to convert potential energy to kinetic energy for electricity generation.
• Tidal energy can be transformed into electrical energy.
• Geothermal power utilizes the Earth's heat, which is readily accessible and used to generate electricity.
• Biomass, being renewable, will be available as long as plants grow. Fast-growing trees such as Euphorbia and Jatropha, get planted.

Biofuels

• Bioethanol is an alcohol made by fermentation.
• It is made from carbohydrates in sugar or starch crops.
• Bioethanol made from corn or sugarcane.
• Bioethanol can derive from beet root through fermentation and distillation.
• Bioethanol and is usable as a fuel for vehicles in its pure form.
• Biodiesel is made from vegetable oils and animal fats.
• Some of India's oil-yielding trees for biodiesel are Ratanjot, Nagchampa, and Rubber seeds.

Nuclear Energy

• Nuclear power generates heat and electricity using exothermic nuclear processes, including fission, decay, and fusion.

Energy Conservation

• Limited resources and increasing demands require conserving energy and improving efficiency.
• Saving energy starts at home, by switching off lights and fans when not in use, minimize common workspace use, using fuel efficient stoves for cooking and use dry branches for tree burning.
• At work, use carpools, switch off unused lights/fans, and turn off computers when not in use.
• Use public transport, maintain lower car speeds, drive moderately, and check vehicles for fuel leaks.
• Turn off vehicle engines at stops to avoid idling.
• CFL’s have mercury, is an element essential to the operation of fluorescent lighting.
• Incandescent bulbs are replaced by CFL (Compact Fluorescent Light Bulbs) & LED (Light Emitting Diode) bulbs.
• CFL bulbs use less electricity: 75% less and LED bulbs use less energy and are lead free, environmentally friendly.
• The Bureau of Energy Efficiency (BEE), created in 2002.
• The BEE develops programs to increase energy conservation and efficient use in India.
• The transport sector is the fastest growing source of greenhouse gases.
• Over 85% of greenhouse gas emissions from transport are CO2 from road transport.
• Reducing energy waste requires improving energy efficiency.