Q)Describe the modern methods employed for the exploration of natural resources.
Ans)Exploration of resources involves complex techniques which depend upon the physical chemical and biological properties of a resources. Now-a-days, in our country, much of the exploration is done by analysis of photographs taken from aircraft or spacecraft(satellites) and other data supplied by the sensors mounted on these vehicles called 'remote sensing'. Some of the methods used for the exploration of resources are
Conventional Methods
In olden days, discovery of minerals or of petroleum was purely accidental. People used to know about to know about the hidden treasures of the earth, when they used to dig out land for water or for construction of houses. Sometimes, while tiling land , farmers struck luck and discovered precious metals and minerals. However in this way they could only hit upon mineral wealth which lay close to the surface. Now, many techniques techniques are used for systematic exploration of hidden resources, and drilling or digging when preliminary services have clearly indicated what is underneath and how much is likely to be found.
Remote Sensing Method
Principle
Remote sensing is a method of collecting information like soil, water, vegetation and minerals , from a remote place such as an aircraft or a satellite. This technique not only enables us to locate various resources, but also helps us to know about their quantity and quality.The simplest device could be a camera carried out by an aeroplane to photograph large areas of land systematically. Television cameras could be mounted on satellites and they could take pictures showing details of clouds, water,forests, or buildings on the earth.Both these are optical methods of remote sensing because visible light is used by cameras. But one could send out radio waves from satellites and observe how they are reflected or observed from the surface of the earth. Usually radio-waves of wavelengths as small as few centimeters called microwaves are used for such studies, because these waves penetrate through the clouds and their reflections also go through the clouds to reach the satellite. Similarly, infra-red signals can be sent from the satellite and reflections studied to reveal the nature of reflecting surface.
Remote Sensing of water resources
Radio waves of shortest wavelengths are called 'gamma rays'. These are given off by atoms of several elements. As a result, the ground soil sends out gamma rays which can be picked by the detectors in the aeroplanes or in the satellites.This emission is affected by the presence of moisture of water in the soil and hence it can be easily detected whether the soil holds water.Moreover, in the pictures taken from space, the wet soil will have all together different appearance as compared to dry or water less soil. Due to presence of moisture, the water rich soil will not only show day time (diurnal) variation in temperature on its surface, but also have a cover of vegetation. Analysis of type, density and the pattern of the vegetation growing on the wet soil helps us in locating the areas of potential ground water. Similarly, the belts of hot springs may be identified and will show up in thermal or infra-red detectors.
Survey of the vegetation cover
Forests of deciduous trees which shed leaves in a certain season can be can be easily identified with the help of pictures taken from the spacecraft specially during autumn when the deciduous trees and there is no snowfall as yet to conceal the vegetation. Vegetation cover can be surveyed by measuring and analyzing infrared reflection, or with the help of photographs. The density of vegetation, shape and size of plants and even size, orientation and health of the leaves can be studied from afar. The pattern of seasonal growth of deciduous trees is different from those of coniferous trees like pine and deodar and thus difference can be detected in the photos taken by the spacecraft.
Plants absorb solar energy to make carbohydrates. A part of the absorbed energy is given out and therefore the leaf temperature remains 10-15 degree C higher than the surrounding air temperature during the sunniest part of the day, and about 5 degree below the air temperature at the cooles thour of the night. So, by measuring ground temperature from a distance, the presence or absence of vegetation can be detected.
Search for mineral deposits
Aerial photos and satellite pictures show very clearly if there is a break in the continuity of layers of the rock, or other unusual features of the surface of the earth. The distinctive linear features are found to be very common centers where mineral deposits and ground water are accumulated. Radio waves and magnetic measurements also provide information about minerals and oil under the surface.
Types of Resource Maps
Based on the types of resources several maps are prepared.
Soil Maps show the type of soil, their composition and biological productivity.
Mineral Maps showing location of various kinds of mineral deposits in relation to settings of the earth's crust.
Hydro logical Maps show presence of underground water aquifers, i.e. , rock formation containing water in recoverable quantity , in terms depth of water.
Snow Cover Maps demarcate the extent of snow packs on high mountains.
Resource mapping
Using various techniques, Resource mapping is done to locate various techniques like water, minerals, forests, vegetation, as well as the types of land. Mapping of resources makes it possible to visualize how land use could be could be managed to best advantage. The rural land use map use tells us about the health of forests and the state of deforestation, about pastures and agricultural crops.It also tells us how much land and of what kind is underutilized. The urban land use map show housing, commercial building, sports facilities, essential services such as roads, water supply and disposal of waste etc.Likewise the preparation of land use maps will focus upon the broader aspects of development such as land use for agriculture, industrialization and urbanization, for obtaining natural resources (forestry, mining etc), water resource development(dams,reservoirs and canals), transportation network,(rails, roads etc.) also the zones prone to natural hazards like flood, cyclones earthquakes landslides avalanches etc,
Ans)Exploration of resources involves complex techniques which depend upon the physical chemical and biological properties of a resources. Now-a-days, in our country, much of the exploration is done by analysis of photographs taken from aircraft or spacecraft(satellites) and other data supplied by the sensors mounted on these vehicles called 'remote sensing'. Some of the methods used for the exploration of resources are
Conventional Methods
In olden days, discovery of minerals or of petroleum was purely accidental. People used to know about to know about the hidden treasures of the earth, when they used to dig out land for water or for construction of houses. Sometimes, while tiling land , farmers struck luck and discovered precious metals and minerals. However in this way they could only hit upon mineral wealth which lay close to the surface. Now, many techniques techniques are used for systematic exploration of hidden resources, and drilling or digging when preliminary services have clearly indicated what is underneath and how much is likely to be found.
Remote Sensing Method
Principle
Remote sensing is a method of collecting information like soil, water, vegetation and minerals , from a remote place such as an aircraft or a satellite. This technique not only enables us to locate various resources, but also helps us to know about their quantity and quality.The simplest device could be a camera carried out by an aeroplane to photograph large areas of land systematically. Television cameras could be mounted on satellites and they could take pictures showing details of clouds, water,forests, or buildings on the earth.Both these are optical methods of remote sensing because visible light is used by cameras. But one could send out radio waves from satellites and observe how they are reflected or observed from the surface of the earth. Usually radio-waves of wavelengths as small as few centimeters called microwaves are used for such studies, because these waves penetrate through the clouds and their reflections also go through the clouds to reach the satellite. Similarly, infra-red signals can be sent from the satellite and reflections studied to reveal the nature of reflecting surface.
Remote Sensing of water resources
Radio waves of shortest wavelengths are called 'gamma rays'. These are given off by atoms of several elements. As a result, the ground soil sends out gamma rays which can be picked by the detectors in the aeroplanes or in the satellites.This emission is affected by the presence of moisture of water in the soil and hence it can be easily detected whether the soil holds water.Moreover, in the pictures taken from space, the wet soil will have all together different appearance as compared to dry or water less soil. Due to presence of moisture, the water rich soil will not only show day time (diurnal) variation in temperature on its surface, but also have a cover of vegetation. Analysis of type, density and the pattern of the vegetation growing on the wet soil helps us in locating the areas of potential ground water. Similarly, the belts of hot springs may be identified and will show up in thermal or infra-red detectors.
Survey of the vegetation cover
Forests of deciduous trees which shed leaves in a certain season can be can be easily identified with the help of pictures taken from the spacecraft specially during autumn when the deciduous trees and there is no snowfall as yet to conceal the vegetation. Vegetation cover can be surveyed by measuring and analyzing infrared reflection, or with the help of photographs. The density of vegetation, shape and size of plants and even size, orientation and health of the leaves can be studied from afar. The pattern of seasonal growth of deciduous trees is different from those of coniferous trees like pine and deodar and thus difference can be detected in the photos taken by the spacecraft.
Plants absorb solar energy to make carbohydrates. A part of the absorbed energy is given out and therefore the leaf temperature remains 10-15 degree C higher than the surrounding air temperature during the sunniest part of the day, and about 5 degree below the air temperature at the cooles thour of the night. So, by measuring ground temperature from a distance, the presence or absence of vegetation can be detected.
Search for mineral deposits
Aerial photos and satellite pictures show very clearly if there is a break in the continuity of layers of the rock, or other unusual features of the surface of the earth. The distinctive linear features are found to be very common centers where mineral deposits and ground water are accumulated. Radio waves and magnetic measurements also provide information about minerals and oil under the surface.
Types of Resource Maps
Based on the types of resources several maps are prepared.
Soil Maps show the type of soil, their composition and biological productivity.
Mineral Maps showing location of various kinds of mineral deposits in relation to settings of the earth's crust.
Hydro logical Maps show presence of underground water aquifers, i.e. , rock formation containing water in recoverable quantity , in terms depth of water.
Snow Cover Maps demarcate the extent of snow packs on high mountains.
Resource mapping
Using various techniques, Resource mapping is done to locate various techniques like water, minerals, forests, vegetation, as well as the types of land. Mapping of resources makes it possible to visualize how land use could be could be managed to best advantage. The rural land use map use tells us about the health of forests and the state of deforestation, about pastures and agricultural crops.It also tells us how much land and of what kind is underutilized. The urban land use map show housing, commercial building, sports facilities, essential services such as roads, water supply and disposal of waste etc.Likewise the preparation of land use maps will focus upon the broader aspects of development such as land use for agriculture, industrialization and urbanization, for obtaining natural resources (forestry, mining etc), water resource development(dams,reservoirs and canals), transportation network,(rails, roads etc.) also the zones prone to natural hazards like flood, cyclones earthquakes landslides avalanches etc,
With a pardon, but the answer is not succinct and not even not close to the question asked. It is about modern methods, and there are number of techniques but you have used only remote sensing and elaborated it in each bullet with same core of answer.
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