Ways to Manage Our Resources
The environment includes our physical surroundings like air, water, soil and all the organisms such as plants, animals, human beings and micro-organisms like bacteria and fungi (called decomposers).
The system of controlling the use of natural resources like forests, wild-life, water, coal and petroleum in such a way as to avoid their wastage and to use them in the most effective way, is called management of natural resources.
Ganga Action Plan
The pollution of river water is caused by the following factors:
- Largely untreated sewage is dumped into the Ganges every day.
- Other human activities like bathing, washing of clothes and immersion of ashes or unburnt corpses also cause pollution.
- Industries also contribute chemical effluents to the Ganga’s pollution load and the toxicity kills fish in large sections of the river.
This multi-crore project came about in 1985 because the quality of the water in the Ganga was very poor. The contamination of river water can be usually found from two factors:
- The presence of coliform bacteria in river water. A coliform is a group of bacteria, found in human intestines, whose presence in water indicates contamination by disease-causing microorganisms.
- Measurement of pH of river water: There are some measurable factors which are used to quantify pollution or the quality of the water that we use for various activities and the pH of water is something that can easily be checked using universal indicator.
The Five R’s to Save the Environment
|This means to say No to things that can harm you and the environment.
|This means that you use Less.
|In the reuse strategy, you simply use things again and again.
|This means when a product can nom0l be used for the original purpose. think carefully and use it for some other Useful purpose.
|This means that you collect plastic, paper, glass and metal items and recycle these materials to make required things instead of synthessing or extracting fresh plastic paper, glass or metal
The concept of sustainable development encourag¬es forms of growth that meet current basic human needs, while preserving the resources for the needs of future generations. It depends upon the willingness of the people to change their perceptions of the so¬cio-economic and environmental conditions around them, and the readiness of each individual to alter their present use of natural resources.
Have you ever visited a town or village after a few years of absence? If so, have you noticed new roads and houses that have come up since you were there last? Where do you think the materials for making these roads and buildings have come from? Try and make a list of the materials and their probable source+s. Discuss the list you have prepared with your classmates. Can you think of ways in which the use of these materials be reduced?
(A) The materials used for road construction are:
(IV) Cement concrete
(a) Both (I) and (II)
(b) Both (II) and (IV)
(c) (II), (III) and (IV)
(d) (I), (II) and (IV)
(A) (d) (I), (II) and (IV)
Explanation: A wide variety of materials are used in the construction of roads which are soil (naturally occurring or processed), aggregates (fine aggregates or coarse aggregates obtained from rocks), binders like lime, bituminous materials, and cement, and miscellaneous materials used as admixtures for improved performance of roads under heavy loads and traffic. Soil constitutes the primary material for the foundation, subgrade, or even the pavement (for low-cost roads with low traffic in rural areas)
(B) Which of the following is not used for the construction of buildings?
Explanation: Building material is any material used for construction purpose such as materials for house building. Wood, cement, aggregates, metals, bricks, concrete, clay are the most common types of building material used in construction.
(C) How is cement used in the construction of buildings and roads obtained?
Cement is manufactured by heating a precise mixture of finely ground Limestone, clay and sand in a rotating kiln to temperatures reaching 1450°C.
(D) Assertion (A): Use of cement and petroleum-based materials for road construction should be reduced.
Reason (R): One of the methods to save the environment is to reduce material cost.
(a) Both (A) and (R) are true and (R) is the correct explanation of the assertion.
(b) Both (A) and (R) are true, but (R) is not the correct explanation of the assertion.
(c) (A) is true, but (R) is false.
(d) (A) is false, but (R) is true.
(c) (A) is true, but (R) is false.
Explanation: Road and building construction causes lot of environmental pollution as they use cement and other petroleum based products which emit large amount of carbon dioxide in the atmosphere. Large part of the emissions worldwide come from the most ubiquitous part of the human-environment – roads. Cement, used in road construction, contributes 1 ton of CO2 per 1 ton of cement produced. Road Industry is increasingly under pressure to reduce carbon footprint. At the same time, efficiency of industrial processes is at its highest. Reductions of C02 emissions must come from new techniques of asphalt production, often using waste products as alternative input materials. Therefore, in order to save our environment, use of cement and petroleum-based materials for road construction should be reduced.