Environmental Studies

“ENVIRONMENT”- DEFINITION AND MEANING:

‘ENVIRONMENT’ means everything surrounding us, that includes dead things, living organisms and the conditions – more scientifically the PHYSICAL, CHEMICAL and BIOLOGICAL conditions.

ENVIRONMENTAL DIVISIONS:From the scientific study point of view, the overall environment & each component thereof is divided into the following two divisions.

PHYSICAL / ABIOTIC (Non-living) Environment.

BIOLOGICAL / BIOTIC (living) Environment.

COMPONENTS OF ENVIRONMENT: ENVIRONMENT

ATMOSPHERE HYDROSPHERE LITHOSPHERE BIOSPHERE

Troposphere Stratosphere Mesosphere

Thermosphere

Ocean/SeaRiver

Springs/falls wells/lakes

CrustUpper Mantle

Combinationof

atmosphere+ Lithosphere+ Hydrosphere and all the

living organisms

ATMOSPHERE – It is the envelope of gases surrounding the earth, comprising a complex mixture of major, minor & trace components.

LITHOSPHERE – It refers to the solid layers of rock materials, on the continents and below the oceans.

HYDROSPHERE – It refers to the layer / cover of water on the earth’s surface in the form of oceans, seas, rivers, lakes and ponds.

BIOSPHERE – It collectively covers the portions of Atmosphere, Lithosphere and Hydrosphere which supports all the life forms.

ATMOSPHERE

HYDROSPHERE: It is refers to the layer or cover of water on the surface

of earth. We all know that the life is not possible without the water.

It is in the form of oceans, sea, rivers & ponds and ground water.

70% of the earth surface is covered by the water It is estimated that the Hydrosphere contains about

1360 million cubic km of water out of which 97 % is in the oceans & sea which is salty , 2% is in form of ice form and only 1 % is pure water available for human consumption

This drinking water is in the form of ground water and in the river which is use by all of us.

Large quantity of ground water is utilize for the agriculture and industries while the waste water from these is much polluted and on mixing with rivers is polluting the rivers also.

The quantity of water vapor arising from evaporation of sea water and river water returns by the same volume to the earth’s surface by rainfall and back to the water source. This natural Hydrological cycle is more or less balanced by cloud formation and rainfall.

Water is essential for all life on the Earth – plants, animals and man.

Elementary Hydrology

It is the cycle, which balance between precipitation and evaporation into atmosphere is called Hydrological Cycle.

1) Evaporation and Transpiration: In the Sun-Shine day water is evaporated from the surface of water sources, it is converted into a small vapor form is called evaporation where as the small practical of water is librated by the plants and Vegetation cover is called transpiration.

2) Precipitation: The form of water fall on the surface of earth is called as precipitation like Rain, Snow, Dew, Hail etc.

3) Infiltration (Percolation): At second precipitation, Rest of Water absorbs by the soil particles and meets to the sub-surface water is call infiltration of water.

Hydrological Cycle:

4) Run-off: Major portion of water at second precipitation run on the surface of the earth and meet to a surface sources like Lakes, streams, River and Oceans is called runoff.

LITHOSPHERE:

It is made of the mental of rocks. It includes the soil that covers the rocks.

Most rocks are composed of minerals. Three types of rocks are recognized by geologists: igneous, sedimentary, and metamorphic.

Igneous rocks are formed by the solidification of magma. This solidification can occur at or below the Earth's surface

Sedimentary rocks develop from the lithification of sediments or weather rock scrap.

Metamorphic rocks are created by the adjustment of existing rocks by strong heat or pressure.

Living organisms, plants and vegetation are supported by the lithosphere.

It contain the resources like minerals, organic & inorganic matter and provide the foods to human being and animals.

Soil is divided in 3 zones as per the depth increase. 1) Top soil layer is the index of quality and contain

max. bulk of organic mater and productivity. Typical soil suitable for the agriculture contain the 5% of organic and 95% in organic matter. Good soil is an asset for the nation.

2) 2nd layer is known as sub soil and contain organic matter + salt and clay partials split from top layer

3) 3rd layer is the parent rock from which the soil was formed.

Minerals are generated through the weathering process like rain ,wind, chemical & biological activities on parent rocks while organic matter is due to plant biomass and population of micro organisms

Lithosphere decompose the organic waste by the micro organisms in the soil

It is important for the agriculture, industrialization transportation etc. and various land forms of the lithosphere is mountain, plateaus and plains

Elements of Highway Materials Properties and Highway Construction

Soil.

Soil : Definition : According to IS : 2809-1972 . Soil is defined

as "Sediments or other unconsolidated accumulation of

soil particles produced by the physical and chemical disintegration of

rocks which may or may not contain organic matter. OR The unconsolidated mineral of earth crust is known as

soil.

Soil Classification System :Following are four most commonly used soil classification system in highway engineering.

Grain or particle size classification

Textural classification

Highway research board classification of soils

Indian standard soil classification.

1. Grain or particle size classification :In this system the classification is based on sizes of soil grains.According to which the soil is classified as gravel, sand, silt and clay.

2) Textural classification :It is based on the particle size distribution where in soils are classified on a triangular diagram.A triangular diagram which relates percentages of the sand, silt and clay fractions in the soil.Fig. shows the most commonly used textural classification chart prepared by the U.S. public roads administration.The sizes of particles for sand, silt and clay are respectively 2 mm to 0.05 mm, 0.05 mm to 0.005 mm and less than 0.005 mm.

3) Highway research board classification of soils :The Highway Research Board (HRB) classification system is also known as Public Road Administration (PRA) classification system or American Association of State Highway Officials (AASHO) classification system.This system is mostly used for pavement construction.In this classification system, the soils are divided into seven groups A-l, A-2, ... .A-7 roughly in decreasing order of stability. Again these groups are subdivided into other groups.A characteristic group index is used to describe the performance of the soil in particular group.The higher the value of the group index, the poorer is the material quality.The group index depends on the following three factors.(i)The amount of material passing through 75 micron IS sieve.(ii)The liquid limit (iii) Plastic limit.The value of group index varies from 0 to 20.The Table can be used as a guide for knowing soil condition on the basis of its group index.

4) Indian standard soil classification.

Testing of Soil Strength :The various test used to determine the strength properties of subgrade soil may be broadly divided into the following three groups :

Shear test

Bearing test

Penetration test

The soil as a highway sub grade serves the following functions :

To provide the support to the road pavement.

To provide good stability to the road pavement.

To provide good drainage to the rain water, percolating through the road pavement.

Function of Soil:

BIOSPHERE:

It collectively covers the portion of Atmosphere, Lithosphere, and Hydrosphere.

Extend from the lowest sea level to about 24 km in atmosphere. Both Biosphere and environment have close interactions with

each other. All living organism interact with each other and support their life.

Life supporting resources are available from the biosphere and waste product in gaseous, liquid and solid forms are discharge in biosphere.

Level of O2 & CO2 is depend on plant word and ultimately on biosphere.

Biosphere is closely related to energy flow in the environment and water chemistry.

IMPECT OF TECHNOLOGY ON THE ENVIRONMENT:

Technological revolution is required for the growth of any developing country like India. But it will damage the natural environment.

The Development and use of Technology produce 1) Direct effect –direct impact are mainly related with use of

land removal of vegetation/forest, urban development, Industrialization….Which, release of pollutants, affecting human health

2)Indirect effect (Chain impact) -Interfere with the natural ecological system like the control of pollution through natural process.

-Global Warming

- Green House Effect

- Acid Rain

- Ozone layer Depletion.

Quantity of CO2 and other chemical component are increase which create the health problems

Rivers are being polluted due the discharge of industrial waste and sewage.

Disposable of radioactive wastes from nuclear reactors create major problems for human health.

Industrial waste pollute all the nature like soil, Drinking water and air.

Fossil fuel are use for power generation and for running vehicles- pollution increase

Industries produce many products which increase the living standards and also the pollution of all type.

ENVIRONMENTAL DEGRADATION:

Pollution

Population Explosion

Exploitation of Natural Resources

Disturbance in Ecosystems

Waste Generation

ROLE OF ENVIRONMENTAL ENGINEER

(MEN-ENVIRONMENT RELATION) :

know and understand the environment

study the problems affecting environment

Try to give solution to these problems

Maintain the progress of the country in harmony with environment

in such a way that the community gets clean and hygienic air,

water and land to live.

OBJECTIVES OR WHY ENVIRONMENTAL AWARENESS?

Study and exploring the nature. (Awareness)

Technological developments.

Practical applications and implementations. (Knowledge)

Post implementation impacts and problems.

Remedial measures and solution findings to the problems.

Means to conserve the nature and environment (Skills)

Prepared by, Dhruvesh Patel

Prepared by, Dhruvesh Patel

www.drdhruveshpatel.com

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