Introduction to environment

Research Assistant em University of Windsor
2 de Aug de 2016

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Introduction to environment

  1. Introduction to Environment Subject: Project Formulation and Environmental Impact Assessment Dhwani Shah,Assistant Professor Bhaikaka Centre for Human Settlements, APIED,VallabhVidyanagar.
  2. What is Environment??  Formed from two words,‘environ’ and‘ment’ which means ‘encircle’ or‘all around’  Environment is a complex of many variables which surround man as well as living organisms.Any external force, substance or condition, which surrounds and effects the life of the organism in any way, becomes a factor of its environment.
  3. Air Environment  Troposphere - sea level/surface of earth to 8-16km. 75% of atmosphere’s mass contained here.Water vapor, major gases.  Stratosphere- Extends to an altitude of 50kms. Ozone layer- absorb ultraviolet radiation.  Mesosphere – extends till 85kms. In temperature decreases as the altitude increases (temp. as low as -93 degree Celsius).The upper mesosphere is also the region of the ionosphere.  Thermosphere – extends to an altitude of 600 kms.Temperature increases with altitude (upto 1727 degree Celsius).  Exosphere- Layer that merges with interplanetary space. Hydrogen and helium are prime gases.
  4. Water Environment  Evaporation is the process by which water changes from a liquid to a gas or vapor.  Transpiration is the process by which moisture is carried through plants from roots to small pores on the underside of leaves, where it changes to vapor and is released to the atmosphere. It is essentially evaporation of water from plant leaves.  They are collectively termed evapotranspiration.  Precipitation is any product of the condensation of atmospheric water vapour that falls under gravity. eg. rain, snow.
  5. Land Environment The Earth is an oblate spheroid. It is composed of a number of different layers as determined by deep drilling and seismic evidence.These layers are:  The core, which is approximately 7,000 kilometers in diameter (3,500 kilometers in radius) and is located at the Earth's center.The core is a layer rich in iron and nickel that is composed of two layers: the inner and outer cores.  The mantle, which surrounds the core and has a thickness of 2,900 kilometers.  The crust, which floats on top of the mantle. It is composed of basalt rich oceanic crust and granitic rich continental. Crust depth -40- kilometer (25-mile), has just 1% of Earth’s mass—contains all known life in the universe.
  6. Biosphere  Biosphere can be viewed as a system or a set of functions that operates together and is dependent on each other.The biosphere is the biological component of earth systems, which also include the lithosphere, hydrosphere, atmosphere and other "spheres"*.  The atmosphere of Earth is the layer of gases surrounding the planet earth that is retained by Earth's gravity.  The hydrosphere in physical geography describes the combined mass of water found on, under, and over the surface of a planet.  Earth's lithosphere includes the crust and the uppermost mantle, which constitute the hard and rigid outer layer of the Earth. *[e.g. cryosphere (the frozen water part of the earth system), anthrosphere (environment that is made or modified by. humans for use in human activities) etc.].
  7. Ecosystem  An ecosystem is a community of living organisms in conjunction with the nonliving components of their environment interacting as a system.  Components-  Biotic (Plants and animals)  Abiotic (things like air, water and mineral soil)  There are many examples of ecosystems -- a pond, a forest, an estuary, a grassland.  These biotic and abiotic components are regarded as linked together through nutrient cycles and energy flows.
  8. Processes of Ecosystems Energy flows and material cycles
  9.  Energy enters the biological system as light energy, or photons, is transformed into chemical energy in organic molecules by cellular processes including photosynthesis and respiration, and ultimately is converted to heat energy.This energy is dissipated, meaning it is lost to the system as heat; once it is lost it cannot be recycled. Without the continued input of solar energy, biological systems would quickly shut down.Thus the earth is an open system with respect to energy.  Elements such as carbon, nitrogen, or phosphorus enter living organisms in a variety of ways. Plants obtain elements from the surrounding atmosphere, water, or soils.Animals may also obtain elements directly from the physical environment, but usually they obtain these mainly as a consequence of consuming other organisms.These materials are transformed biochemically within the bodies of organisms, but sooner or later, due to excretion or decomposition, they are returned to an inorganic state. Often bacteria complete this process, through the process called decomposition or mineralization.  During decomposition these materials are not destroyed or lost, so the earth is a closed system with respect to elements (with the exception of a meteorite entering the system now and then).The elements are cycled endlessly between their biotic and abiotic states within ecosystems.Those elements whose supply tends to limit biological activity are called nutrients.  In reality the organization of biological systems is much more complicated than can be represented by a simple "chain".There are many food links and chains in an ecosystem, and we refer to all of these linkages as a food web. Food webs can be very complicated, where it appears that "everything is connected to everything else”
  10. Marine Food chain Marine Food Web
  11. Environment Resources  Environment resources refer to components that have an intrinsic value of their own, or are of value for long term sustainability and use by human.  Types-  Renewable resources - Capable of natural regeneration . Once degraded beyond certain level, they may never recover. Eg. clean water, Clean air, Soil, flora, fauna  Non-renewable resources - Rate of their renewal is so slow that they are regarded as available only in fixed quantities. Eg. Minerals, ground water  Continuous resources – Eg. Solar energy, wind, gravity, tidal energy  Extrinsic resources - prone to breakdown and degradation. Eg. Human skills
  12. Fresh Water  Types of FreshWater Resources  Standing water bodies (lakes, reservoirs)  Flowing water bodies (Surface water- streams, rivers)  Ground water (97.6% salty sea water, non-sea water- 87% of solid polar cap, 12% ground water, 1% surface water)  If burning issues related to fresh water ecosystems such as pollution and over exploitation are not addressed immediately, the diverse communities found in lakes, rivers, and wetlands will be lost in no time.  Greater danger of further losses from dams, pollution, overfishing, and other threats.
  13. Oceans and Coasts  Economic opportunities (industries, tourism, mineral extraction, shipping) offered by coastal areas lead to high population growth rates and consequent environmental problems.  Eg-  Mangrove forests are under pressure to be exploited for their wood resources and because the land beneath them can be drained and reclaimed from the sea for development.  Corals and marine life under threat due to shipping/ port activities.
  14. Air  Global energy requirement – Fossil fuel [Oil (38%), Coal and Lignite (26.5%), Natural gas (20.9%)] and renewable energy.*  Air pollution – Pollutants that come from the combustion of fossil fuels include sulphur dioxide (SO2), nitrogen oxides (NOx), particulate matter (PM), carbon monoxide (CO), carbon dioxide (CO2)  Eg. Nitrogen oxide  Emissions -Cars and trucks, Coal-fired power plants, Large industrial operations, Ships and airplanes  which contribute to the formation of smog and acid rain  Smog- type of air pollution derived from vehicular emission from internal combustion engines and industrial fumes that react in the atmosphere with sunlight to form secondary pollutants. It is harmful for people with heart and lung conditions such as bronchitis and asthma. It can inflame breathing passages, decrease the lungs' working capacity, cause shortness of breath, pain when inhaling deeply, wheezing, and coughing.  Acid rain - is a rain or any other form of precipitation that is unusually acidic, meaning that it possesses elevated levels of hydrogen ions (low pH). It can have harmful effects on plants, aquatic animals and infrastructure.Acid rain is caused by emissions of sulfur dioxide and nitrogen oxide, which react with the water molecules in the atmosphere to produce acids. *Source: Essentials of Environmental studies- Kurian Joseph, R. Nagendran
  15. Wetlands  Immense variety of species of microbes, plants, insects, amphibians, reptiles, birds, fish and mammals can be part of wetland.They provide great volume of food that attract many animal species.  Importance-  Counter erosion  Help ground water recharge  Deposit nutrient rich silt (Help grow crops)