2“ENVIRONMENT”- DEFINITION AND MEANING: ‘ENVIRONMENT’ means everything surrounding us, that includesdead things, living organisms and the conditions – more scientificallythe 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.
3COMPONENTS OF ENVIRONMENT: ENVIRONMENT ATMOSPHERE BIOSPHERE HYDROSPHERELITHOSPHEREBIOSPHERETroposphere Stratosphere MesosphereThermosphereOcean/SeaRiverSprings/falls wells/lakesCrustUpper MantleCombinationofatmosphere+ Lithosphere+ Hydrosphere and all the living organisms
4ATMOSPHERE – 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, onthe continents and below the oceans.HYDROSPHERE – It refers to the layer / cover of water on theearth’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.
6HYDROSPHERE: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 waterIt 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 consumptionThis drinking water is in the form of ground water and in the river which is use by all of us.
8Large 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.
10Hydrological Cycle:It is the cycle, which balance between precipitation and evaporation intoatmosphere is called Hydrological Cycle.1) Evaporation and Transpiration:In the Sun-Shine day water is evaporated from the surface of watersources, it is converted into a small vapor form is called evaporationwhere as the small practical of water is librated by the plants andVegetation 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 particlesand meets to the sub-surface water is call infiltration of water.
114) Run-off:Major portion of water at second precipitation run on the surface ofthe earth and meet to a surface sources like Lakes, streams, Riverand Oceans is called runoff.
13It is made of the mental of rocks 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 surfaceSedimentary 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.
14It 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 layer3) 3rd layer is the parent rock from which the soil was formed.
15Minerals 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 organismsLithosphere decompose the organic waste by the micro organisms in the soilIt is important for the agriculture, industrialization transportation etc. and various land forms of the lithosphere is mountain, plateaus and plains
16Elements of Highway Materials Properties and Highway Construction Soil.
17Soil :Definition : According to IS : Soil is defined as"Sediments or other unconsolidated accumulation of soil particlesproduced by the physical and chemical disintegration of rocks whichmay or may not contain organic matter.ORThe unconsolidated mineral of earth crust is known as soil.
18Soil Classification System : Following are four most commonly used soil classificationsystem in highway engineering.Grain or particle size classificationTextural classificationHighway research board classification of soilsIndian standard soil classification.
191. 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.
202) Textural classification : It is based on the particle size distribution where in soils areclassified on a triangular diagram.A triangular diagram which relates percentages of the sand, siltand clay fractions in the soil.Fig. shows the most commonly used textural classificationchart prepared by the U.S. public roads administration.The sizes of particles for sand, silt and clay are respectively2 mm to 0.05 mm, 0.05 mm to mm and less than mm.
223) Highway research board classification of soils : The Highway Research Board (HRB) classification system is alsoknown as Public Road Administration (PRA) classification systemor 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 groupsA-l, A-2, ... .A-7 roughly in decreasing order of stability. Again thesegroups are subdivided into other groups.A characteristic group index is used to describe the performance ofthe soil in particular group.The higher the value of the group index, the poorer is the materialquality.The group index depends on the following three factors.The amount of material passing through 75 micron IS sieve.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 onthe basis of its group index.
27Testing of Soil Strength : The various test used to determine the strength properties ofsubgrade soil may be broadly divided into the following three groups :Shear testBearing testPenetration test
28Function of Soil: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 throughthe road pavement.
30It 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.
31IMPECT 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 produce1) Direct effect –direct impact are mainly related with use of land removal of vegetation/forest, urban development, Industrialization….Which, release of pollutants, affecting human health2)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.
32Fossil 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.Quantity of CO2 and other chemical component are increase which create the health problemsRivers 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.
33ENVIRONMENTAL DEGRADATION: PollutionPopulation ExplosionExploitation of Natural ResourcesDisturbance in EcosystemsWaste Generation
34ROLE OF ENVIRONMENTAL ENGINEER (MEN-ENVIRONMENT RELATION) :know and understand the environmentstudy the problems affecting environmentTry to give solution to these problemsMaintain the progress of the country in harmony with environmentin such a way that the community gets clean and hygienic air,water and land to live.
35OBJECTIVES 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)