Thursday, November 19, 2015

Rain water Harvesting

Rain Water Harvesting (RWH) is the process of collecting, conveying & storing water from rainfall.
The following methodologies are adopted for rain water harvesting:

  • Roof Rain Water Harvesting
  • Land based Rain Water Harvesting
  • Watershed based Rain Water harvesting
  • For Urban & Industrial Environment
    • Roof & Land based RWH
    • Public, Private, Office & Industrial buildings
    • Pavements, Lawns, Gardens & other open spaces
The advantages of Rain Water Harvesting are:

  • It provides self-sufficiency to water supply
  • It Reduces the cost for pumping of ground water
  • It Provides high quality water, soft and low in minerals
  • It Improves the quality of ground water through dilution when recharged
  • It Reduces soil erosion & flooding in urban areas
  • The rooftop rain water harvesting is less expensive &easy to construct, operate and maintain
  • In deserts, RWH the only relief
  • In saline or coastal areas & Islands, rain waterprovides good quality water

Rainwater Harvesting helps in the following ways:

  • It helps arrest ground water decline and augments groundwater table.
  • It improves water quality in aquifers
  • It helps conserve surface water runoff during monsoon
  • It helps reduce soil erosion
  • It instills a culture of water conservation.

Broadly there are two ways of harvesting rainwater:

  • Surface runoff harvesting :- In urban area rainwater flows away as surface runoff. This runoff could be caught and used for recharging aquifers by adopting appropriate methods 
  • Roof top rainwater harvesting:- It is a system of catching rainwater where it falls. In rooftop harvesting,the roof becomes the catchments, and the rainwater is collected from the roof of the house/building. It can either be stored in a tank or diverted to artificial recharge system.This method is less expensive and very effective and ifimplemented properly helps in augmenting the groundwater level of the area

Rooftops are favoured becauseof the large coefficient of run-offgenerated from them andrelatively less likelihood of theircontamination.
The water that leaves the rooftop may be 65 – 90% of the water that falls on it Roof material absorbs some water Evaporation losses More water loss if roof is flat
the water transported from the catchment surface to the storage tank

FILTER AND FIRST FLUSH DEVICES remove grit, leaves and dirt that the rainwater may transport from the catchment, before the water enters the storage tank.
A first flush device diverts the water from the first rain so that it does not enter the storage tank.
A filter can be prepared using gravel sand, charcoal and gravel.
The first rain carries with it a lot of filth from the rooftop and dissolved air pollutants. This rainwater should be diverted away from the storage tank using a first flush device.
DELIVERY SYSTEM that convey the store drain water till the point of end-use. It is not recommended to use harvested rainwater for drinking, cooking and dish washing
From the simplest ground level tank, surface lined ponds and large lakes there are many storage options depending on the context of the rainwater harvesting design.
Above ground, Ground level or Intermediate floor level Save on pumping cost
Excess water can be diverted into a groundwater recharge system

Water obtained from RWH can be:

  1. Stored for direct use
  2. Used to recharge ground water aquifers
  3. Used to recharge bore wells
  4. Used to recharge Pits
  5. Used to soak away or recharge shafts
  6. Used to recharge dug wells
  7. Used to recharge trenches
  8. Used  as percolation tanks

Sunday, September 13, 2015

Environmental Ethics

There is an urgent need to inculcate sensitivity towards environmental degradation among people by fostering environmental ethical values.  Environmental Ethics attempts to define what is right and what is wrong regardless of cultural differences. We human beings have a fundamental duty towards nature to respect and care for the Earth, protect life-support systems, biodiversity and ensure sustainable development.
The following are the environmental ethical values to be inculcated:

  • Environmental consciousness
  • Humility and reverence
  • Responsibility and commitment
  • Respect for all forms of life and landscape
  • Global environmental citizenship
  • Self-reliance
  • Adoption of eco-friendly culture
  • Preservation of diversity on the planet
  • Sharing a common environment
The spectrum of environmental activities for inculcating environmental ethical values are:
  • Using recycled paper for notes and circulars
  • Diverting wastes from kitchen to the garden
  • Switching off unnecessary lights
  • Using bicycles or walking
  • Using public transport systems
  • Collecting rainwater
  • Avoiding usage of freshwater for gardening
  • Using cloth towels instead of paper towels
  • Avoiding unnecessary outdoor lighting
  • Organizing tree-plantation campaigns
  • Reducing volume of radio and television to reasonable levels
  • Listening to radio programs on environment and its problems
  • Organizing eco-clubs
  • Placing trash cans and dustbins around the college premises
  • Observing Environment day on 5th June and Earth day on 22nd April
  • Planting trees in and around the campus
  • Encouraging healthy lifestyles through balanced nutrition, exercise and yoga
  • Helping enforce environment protection laws
  • Staging short plays on environmental crisis to create environmental awareness
  • Conserving energy resources by avoiding unnecessary wastage of energy
  • Cutting and displaying pictures and newspaper cuttings depicting environmental crisis

Saturday, May 9, 2015


Natural Capital

Environmentally sustainable City

Schematic representation of Structure of an Ecosystem

Question paper for Environmental Studies (9030) On 10 Dec 2014

Answers to Environmental Studies Questions


Disaster Management








Environmental Studies - Biodiversity, Environmental Pollution and Legislation along with miscellaneous topics

Natural resources: Water resources

Ecological pyramids

Energy flow in an ecosystem

Energy flow in an ecosystem - Single channel and Universal flow models

Structure and Function of an Ecosystem

Food chains Vs Food webs

Agriculture - Effects of modern methods and options

Natural resources - Land resources

Multidisciplinary nature of Environmental Studies

Environmental Studies - The need for public awareness


Four basic principles of ecology

Importance of Environmental Studies

Environmental Studies - Introduction


Environmental Studies Syllabus (Osmania University)

Important questions and answers

Multidisciplinary nature of environmental science

Biogeochemical cycles - Carbon cycle in brief

Biogeochemical cycles: Sulphur cycle

Biogeochemical cycles - Oxygen cycle

Biogeochemical cycles - Nitrogen cycle

Biogeochemical cycles: Phosphorus cycle

The Water Cycle

Question Bank

Disaster management in India

Issues involved in enforcement of environmental legislation

Acid rain - Formation, Effects and Control measures

Ozone layer depletion

Global warming - Definition, Effects, Control and Remedial measures

Climate change - causes and effects

Envionmental ethics

Population Explosion

Watershed management

Water conservation

Solid waste management - sources, effects and methods of disposal

Thermal pollution - causes, effects and control measures of thermal pollution

Noise pollution - Causes, types, effects and control of noise pollution

Soil pollution - Types, effects, sources and control of soil pollution

Water pollution - types, effects, sources and control of water pollution

Air Pollution - causes, effects and control measures

Environmental Pollution

Endangered and Endemic species of India

Conservation of biodiversity

Functions of biodiversity, Vaue of biodiversity and threats to biodiversity

Biogeographical classification of India

Biodiversity - Genetic, Species and Ecosystem diversity

Aquatic ecosystems - Estuaries

Aquatic ecosystem - Oceans

Aquatic Ecosystems - River or Stream

Aquatic ecosystems - Lakes

Aquatic ecosystem-Ponds

Ecological Pyramids


Land degradation- Land slides, Soil erosion and Desertification

Land as a Resource

Alternate Renewable Energy Sources

Non-renewable energy sources

Renewable energy sources

Energy resources, Growing energy needs, Renewable and non-renewable energy sources

Effects of modern agriculture - Fertilizer Pesticide problems, Water logging, Salinity

Dams - Benefits and problems

Conflicts over water

Natural resources: Droughts

Natural resources-Floods

Natural resources: Water resources - Use and Over-use

Environmental Studies - Definition, scope & importance, need for public awareness

Kyoto Protocol

Disaster management - Floods

Disaster management - Landslides

Disaster management - Earthquakes

Forest conservation act, 1980

Wildlife Protection Act, 1972

Water (prevention and control of pollution) act, 1974

Air (prevention and control of pollution) act, 1981

Environment Protection Act, 1986

Important questions-ii

Important questions-i


Rainwater Harvesting

The Water Cycle

The Sulphur cycle

The Phosphorus cycle

Oxygen cycle

The Nitrogen cycle

The Carbon cycle

Monday, April 6, 2015

Natural Capital

Natural capital is the sum of natural resources and natural services. Examples of natural resources and natural services are listed below:

Natural resources:

  • Air
  • Water
  • Land
  • Soil
  • Life (Biodiversity)
  • Non renewable minerals (Iron, Copper, Sand)
  • Renewable energy (Sun, Wind, Flowing water) and
  • Non renewable energy (Fossil fuels, Nuclear power)

Natural services:

  • Air purification
  • Water purification
  • Soil renewal
  • Nutrient recycling
  • Food production
  • Pollination
  • Grassland renewal
  • Forest renewal
  • Waster treatment
  • Climate control
  • Population control (Species interaction) and
  • Pest control

Environmentally sustainable City

An envitonmentally sustainable city or ecocity or green city emphasizes the following points:

Preventing pollution and reducing waste
Using resources and matter resources efficiently
Recycling, reusing and composting atleast 60% of all municipal solid waste
Using solar and other locally available, renewable energy resources
Protecting and encouraging biodiversity by preserving surrounding land

The following are examples of green cities in the world:
Curitiba (Brazil)
Waitakere city (New Zealand)
Leicester (England)
Portland (Oregon, USA)
Davis (California, USA)
Olympia (Washington, USA)
Chattanooga (Tennessee, USA)