ES
UNIT-1NATURAL RESOURCES AND ASSOCIATED PROBLEMS Q1) Explain forest resources in brief and define deforestation with causes and effects.A1) Forests provide clean water and air, timber for wood products, wildlife habitats, stable soil, and recreational opportunities, and they beautify the environment. Furthermore, they are also an important economic resource-producing marketable timber. Despite this economic value, much forestland is being taken out of forest production, largely due to urban sprawl, which has claimed forested areas that will never be replaced. People who live in forests or nearby, know the value of forest resources because their lives and livelihoods depend directly on these readily available resources. However, the rest of the people also derive great benefits from forests which we might not be aware of. The water we use depends on the existence of forests and the watersheds around river valleys. Our homes, furniture, and paper are made from wood from the forest. We make use of many medicines that are based on forest produces. And we depend on the oxygen that plants give out and also on the removal of carbon dioxide we breathe out in the air. People have used forests in our country for thousands of years. As agriculture spread, the forests were cleared or left in patches that were controlled mostly by the tribal people. They hunted animals and gathered plants and lived entirely on forest resources. Deforestation became a major concern when a large amount of timber was extracted for building ships. This led to a great loss in the forest cover and gradual degradation of forests.Forest functions.Watershed protection: • Reduce the rate of surface run-off of water.• Prevent flash floods and soil erosion.• Produces prolonged gradual run-off and thus prevents effects of drought. Atmospheric regulation: • Absorption of solar heat during evapotranspiration.• Maintaining carbon dioxide levels for plant growth.• Maintaining the local climatic conditions. DeforestationDeforestation is the practice of permanent removal of trees to make room for something besides the forest. This can include clearing the land for agriculture or grazing or using the timber for fuel, construction, or manufacturing. The places where civilizations have looked after their forests by using forest resources cautiously, they have prospered; whereas the places where the forests were destroyed, the people gradually impoverished. Today, logging and mining are serious causes of the loss of forests. Dams that were built for hydroelectric power or irrigation submerged the forests and have now displaced the tribal people whose lives depended on the forests. Developing alternatives to deforestation can help decrease the need for tree clearing. For example, the desire to expand the amount of land used for agriculture is an attractive reason to deforest an area. But if people tried adopting sustainable farming practices or implemented new farming technologies on crops, the need for more land might be diminished. Forests can also be restored, through replanting trees in cleared areas or simply allowing the forest ecosystem to regenerate over time.Q2) Discuss floods and droughts.A2)Drought In most arid regions of the world, the rains cannot be predicted. This leads to periods when there is a serious scarcity of water to drink, use in farms, or provide for urban and industrial use. Drought prone areas are thus faced with irregular periods of famine. Agriculturists have no income in the years of scarcity, and as they have no steady income, they have a constant fear of droughts. While it is not entirely possible to prevent the failure of the monsoon, good environmental management can reduce its ill effects. The scarcity of water during drought years affects households, agriculture, and industry. It also leads to food shortages and malnutrition which especially affects children.Measures:In the time when the monsoon is adequate, we use up the ample supply of water without trying to conserve it and use the water judiciously. Thus, during a year when the rains are scarce, there is no water even for drinking in the drought area. Deforestation is one of the factors that worsen the effect of drought. Once hill slopes are cleared of forest cover, the rainwater rushes down the rivers and is lost. Forest cover permits water to percolate in the area permitting it to seep into the ground. This increases the underground stores of water level in natural aquifers. This can be used in the time when drought hits if the stores have been filled during a good monsoon. Flood Floods have been known to be a serious environmental hazard for centuries. However, the havoc raised by rivers overflowing their banks has become progressively more damaging, as people have deforested catchments and intensified the use of river flood plains that once acted as safety valves. Wetlands in flood plains are normally, nature’s flood control system into which overfilled rivers could spill and which would act like a temporary sponge holding the water, thus preventing fast-flowing water from damaging surrounding land. Deforestation in the Himalayas causes floods that year after year kills people, damage crops, and destroy homes in the Ganges and its tributaries and the Brahmaputra. During floods, rivers change their course, and tons of valuable soil is lost to the sea. As the forests get degraded, rainwater does not percolate into the subsoil but runs off down the mountainside carrying large amounts of topsoil. This blocks rivers temporarily but gives way as the pressure mounts allowing enormous quantities of water to wash suddenly down into the plains below. There, rivers swell, burst their banks, and floodwaters spread to engulf peoples’ farms and homes. Q3) Discuss mineral resources and environmental effects of extraction.A3) Minerals were formed for millions of years in the earth’s crust. Iron, aluminium, zinc, manganese, and copper are important raw materials for industrial use. Important non-metal resources include coal, salt, clay, cement, and silica. The stone which is used for building material, such as granite, marble, limestone, constitute another category of minerals. Minerals with special properties that man values for their aesthetic and ornamental value are gems such as diamonds, emeralds, rubies. The lustre of gold, silver, and platinum is used for ornaments. Minerals in the form of oil, gas, and coal were formed when ancient plants and animals were converted into underground fossil fuels. Minerals and their ores need to be extracted from the earth’s interior so that they can be used. This process is known as mining. Mining operations generally go through four stages:(1) Prospecting: Searching for minerals.(2) Exploration: Assessment of the size, shape, location, and economic value of the deposit.(3) Development: The task of preparing access to the deposit so that the minerals can be extracted from the site.(4) Exploitation: Extracting the minerals from the mines. In the past, mineral deposits were discovered by prospectors in areas where mineral deposits the exposure on the surface in minute forms.Environmental problems: Mining operations are considered one of the main sources of environmental degradation. The extraction of all these products from the lithosphere has a variety of side effects. Depletion of available land caused due to mining, waste from industries, conversion of land to industry, and pollution of land, water, and air by dumping industrial wastes, are environmental side effects of the use of these non-renewable resources. Public awareness of this problem is global and government actions to stem the damage to the natural environment has led to numerous international agreements and laws directed toward the prevention of activities and events that may adversely affect the environment. Q4) What are World food problems?A4) In many developing countries where populations keep growing rapidly, the production of food is unable to keep pace with the growing demand and is insufficient. Food production in 64 of the 105 developing countries is lagging as compared to their population growth levels. Many of these countries are unable to produce more food or do not have the financial means to import it from other countries. India is one of the countries that have been able to produce enough food by cultivating a large proportion of its arable land through irrigation. The Green Revolution which happened in the 60’s reduced starvation in the country. However, many of the technologies we have used to achieve this are now being questioned. • Our fertile soils are being exploited faster than they can recuperate.• Forests, grasslands, and wetlands have been converted to agricultural use, which has led to serious ecological questions.• Our fish resources, both marine, and inland, show evidence of exhaustion.• There are great disparities in the availability of nutritious food. Some communities such as tribal people still face serious food problems leading to malnutrition, especially among women and children. Today the world is seeing a changing trend in dietary habits. As living standards keep on improving, people are eating more non-vegetarian food. As people shift from eating grain to meat, the world’s demand for feed for livestock based on agriculture increases as well. This requires more land per unit of food produced and this results in the world’s poor not getting enough to eat. Q5) Define different types of energy in brief.A5) There are three main types of energy; those classified as non-renewable; those that are said to be renewable; and nuclear energy, which uses such small quantities of raw material (uranium) that supplies are to all effect, limitless. However, this classification is inaccurate because several of the renewable sources, if not used ‘sustainably’, can be depleted more quickly than they can be renewed.Non-renewable energy: For producing electricity from non-renewable resources the material is to be ignited. The fuel is placed in a well-contained area and set on fire. The heat generated turns water to steam, which moves through pipes, to turn the blades of a turbine. This converts magnetism into electricity, which we use in various appliances. Sources of non-renewable energy consist of the mineral-based hydrocarbon fuels coal, oil, and natural gas, that were formed from ancient prehistoric forests. They are known as ‘fossil fuels’ because they are formed after life is fossilized. Renewable energy: Renewable energy systems use resources that are constantly replaced and are usually less polluting. Renewable energy technologies will improve the efficiency and cost of energy systems. We may reach the point when we may no longer rely mostly on fossil fuel energy.Some major sources of energy are:Hydro-electric power. Solar energy. Photovoltaic energy. Solar-Thermal electric power. Biomass energy. Biogas. Tidal and wave power. Geothermal energy. Nuclear energy. Q6) Explain Land resources and land degradation.A6) Landforms such as hills, valleys, plains, river basins, and wetlands include different resource generating areas that the people living in them are dependent on. Many traditional farming societies had ways of conserving areas from which they used resources. If the land is utilized carefully it can be considered a renewable resource. The roots of trees and grasses bind the soil together. If forests are depleted, or grasslands overgrazed, the land becomes unproductive and becomes a wasteland. Intensive irrigation leads to waterlogging and salination on which crops cannot be cultivated. The land is also converted into a non-renewable resource when highly toxic industrial and nuclear wastes are dumped on it. Land on earth is as finite as any of our other natural resources. Man needs to protect wilderness areas in forests, grasslands, wetlands, mountains, coasts, etc. to protect our vitally valuable biodiversity. Thus, rational use of land needs careful planning.Land degradation:When soil is used by farming extensively, it is eroded more rapidly by wind and rain. Over irrigating farmland leads to salinization, as evaporation of water brings the salts to the surface of the soil on which crops cannot grow. Over irrigation also creates waterlogging of the topsoil so that crop roots are affected and the crop deteriorates. The use of more and more chemical fertilizers poisons the soil so that eventually the land becomes unproductive. As urban centres grow and industrial expansion occurs, the agricultural land and forests shrink. This is a serious loss and has long term ill effects on human civilization. Q7) What is the role of an individual in the conservation of resources?A7) An individual can play a significant role in the conservation of resources by doing the following activities: • Turn off lights and fans as soon as you leave the room.• Use tube lights and energy-efficient bulbs that save energy rather than bulbs. A 40 W tube light gives as much light as a 100 W bulb.• Keep the bulbs and tubes clean. Dust on tubes and bulbs decreases lighting levels by 20 to 30 percent.• Switch off the television or radio as soon as the program of interest is over.• A pressure cooker can save up to 75 percent of the energy required for cooking. It is also faster.• Keeping the vessel covered with a lid during cooking, helps to cook faster, thus saving energy.
0 matching results found