Class 8 Social Science Chapter 1 Natural Resources and Their Use (New Course)

Key Concept: Real-World Application, Numerical and Analytical Difficulty

a) Seasonal flow variations, historical usage, climate impact
[Solution Description] In negotiating water-sharing agreements, several factors must be evaluated: the seasonal flow variations of the river, downstream vs. upstream rights, historical usage patterns, legal precedents, and existing treaties. Moreover, equitable access considers socio-economic impacts on communities depending on the river and environmental sustainability ensuring long-term availability. Countries must also factor in climatic changes affecting water levels and potential compensations for adversely affected regions. Such comprehensive considerations help balance needs fairly and mitigate conflicts.

Key Concept: Importance of Renewable Resources Management

b) To ensure long-term availability and ecosystem balance
[Solution Description] Sustainable management of renewable resources such as timber is crucial because it ensures that these resources remain available for future generations. Over-harvesting can lead to habitat destruction and loss of biodiversity, which are key components of ecosystem functions. By managing these resources sustainably, we maintain balance in the ecosystem, ensuring that services such as carbon storage, soil stability, and oxygen production continue effectively.

Key Concept: Energy Source Identification

b) Renewable with existing glaciers and forests
[Solution Description]
River water is considered a renewable resource when glaciers and forests exist because these help maintain the water cycle and ensure continuous flow and regeneration of the resource. Thus, under these conditions, rivers provide a sustainable source of energy.

Key Concept: Challenges of Organic Farming Transition

c) Initial yield drop due to soil recovery; diversified crops and used natural inputs, resulting in long-term gains
[Solution Description] Initially, Pema’s family faced declining yields as the soil recovered from chemical use. They overcame these challenges by using compost and natural pest repellents made from neem and garlic. Additionally, diversifying crops helped stabilize their farm’s productivity, eventually leading to thriving yields and premium market prices.

Key Concept: Economic Feasibility

d) It balances extraction costs with usage benefits
[Solution Description] Economic feasibility refers to the cost-effectiveness of extracting and using a natural element. An entity is considered a resource when the benefits derived from its use outweigh the costs involved in its extraction and processing. High expenses without corresponding benefits mean that despite technological and cultural acceptance, the element might not be exploited effectively.

Key Concept: Resource Consumption, Renewable Energy Transition

c) Investing in solar and wind infrastructures and retraining coal industry workers
[Solution Description] For an effective transition from coal to renewable energy, investing in solar and wind infrastructure development while simultaneously retraining workers from the coal industry for renewable energy jobs ensures economic stability. This strategy minimizes unemployment risks and supports broader economic resilience during the transition phase.

Key Concept: Case of Cement Production

b) They reduce environmental pollution
[Solution Description] The production of cement is highly polluting due to the emission of fine dust and other pollutants during manufacturing. Hence, there is an increasing focus on using alternative building materials such as stone, mud, and recycled plastics that offer lower environmental impact. Such materials help decrease pollution and are encouraged by environmental guidelines aiming to minimize industrial emissions.

Key Concept: Understanding the concept of ‘Nature’ and resource utilization

c) When used for human sustenance or consumption
[Solution Description]
An element of nature becomes classified as a ‘resource’ when it is utilized for human sustenance or consumption. This involves transforming the element into something that meets human needs or wants. For example, trees in a forest are part of nature, but when they are cut down to produce furniture, they become resources because they fulfill a specific human need.

Key Concept: Resources essential for life

a) Air
[Solution Description] Air is a natural resource that is essential for human life as it contains oxygen which we need to breathe. It occurs naturally in the environment and cannot be produced or manufactured by humans. The other options like plastic, steel, and synthetic fabrics are man-made materials and not natural essentials for life.

Key Concept: Difference between Renewable and Non-Renewable Resources

c) To reduce dependence on finite resources and ensure energy security
[Solution Description]
The use of renewable resources such as solar or wind power reduces dependency on finite resources like fossil fuels, thereby lowering carbon emissions and environmental impact, ensuring long-term energy availability.

Key Concept: Sustainable Practices, Technological Integration

c) Aligning material selection with regional climates and resources
[Solution Description] When designing eco-friendly building materials, integration with local climatic conditions and resource availability is crucial. By focusing on materials that are abundant or renewable within the region, pollution can be minimized. Furthermore, incorporating technological advances enhances efficiency and reduces production costs. Therefore, understanding local needs and resources allows for sustainable development that aligns with both environmental goals and societal progress.

Key Concept: Sustainable Resource Management

d) All of the above
[Solution Description] Responsible management of non-renewable resources is essential to ensure their availability for future generations while transitioning to sustainable alternatives. Non-renewable resources such as fossil fuels are finite and deplete over time. By managing these resources judiciously, we can slow their depletion rate, allowing more time for the development of renewable energy technologies. Additionally, careful management can reduce environmental impact, mitigate climate change effects, and promote economic stability by avoiding sudden shortages or price spikes caused by resource scarcity.

Key Concept: Pollution and Natural Resources Management

b) Pollution of water bodies
[Solution Description] Industrial waste, when discharged into rivers and other water bodies, leads to pollution that can disrupt aquatic ecosystems. The toxic substances in the waste harm aquatic life by reducing oxygen levels and introducing harmful chemicals. This pollution impacts biodiversity as it may cause the death of many aquatic species and alter the natural balance of the ecosystem.

Key Concept: Understanding Nature as Resources

a) Using soil for agriculture
[Solution Description] An element of nature, such as trees, becomes a resource when it is utilized for human needs. For instance, timber from trees can be used for building materials, making paper, and other applications, thus transforming its natural existence into a valuable resource.

Key Concept: Conflicts and Management

Correct answer option: c) Conflicts over water sharing
[Solution Description] When a river traverses different regions, it often becomes a source of conflict due to competing demands on its water resources. Without effective management and negotiation, these conflicts can escalate into disputes affecting regional stability and cooperation.

Key Concept: Geographical distribution of natural resources and its impact

b) It supports both agriculture and transportation
[Solution Description]
Rivers provide vital resources for agriculture by irrigating land, thus boosting crop production. They also offer transportation routes for trade, facilitating economic interactions. Regions with rivers tend to develop industries that rely on ample water supply and transportation options.

Key Concept: Resources for energy

d) Coal
[Solution Description]
Coal is a critical resource for generating electricity, especially in thermal power plants. In these plants, coal is burned to heat water in boilers, producing steam. The steam drives turbines connected to generators that produce electricity. Therefore, coal’s role as an energy source makes it indispensable for such applications.

Key Concept: Concept of the Natural Resource Curse

a) Poor governance and lack of transparency
[Solution Description] The ‘natural resource curse’ refers to situations where countries with abundant natural resources experience less economic growth due to various reasons, such as poor governance, lack of diversification in industries, and over-reliance on resource exports. This phenomenon can lead to economic instability and slow development.

Key Concept: Renewable vs Non-renewable Resources

b) It supports life by providing oxygen
[Solution Description]
Air is vital for respiration in most living organisms; it contains oxygen which is required for energy production at the cellular level through aerobic respiration. Without air, life cannot be sustained.

Key Concept: Sustainable Management, Renewable Resources

c) 150 cubic meters
[Solution Description] For sustainable management, the amount of wood harvested should equal the annual growth. Given a current storage of 5000 cubic meters of wood and a growth rate of 3\%, the amount of wood that can be sustainably harvested annually can be calculated as:
$Harvest = Current\ Storage \times Growth\ Rate$
Substitute the given values:
$Harvest = 5000 \times 0.03 = 150$
Therefore, 150 cubic meters of wood can be sustainably harvested annually.

Key Concept: Restoration and regeneration of renewable resources

b) Water harvesting
[Solution Description]
Traditional practices for raising groundwater levels include water harvesting, which involves collecting rainwater and directing it into aquifers. This helps in replenishing the groundwater table effectively.

Key Concept: Overexploitation of groundwater in Punjab

c) High-yielding varieties of wheat and paddy
[Solution Description] In the 1960s, farmers in Punjab shifted to using high-yielding varieties of wheat and paddy. These crops required more water than traditional seeds, leading to increased extraction of groundwater to meet their needs. This shift significantly contributed to the overexploitation of groundwater resources in Punjab.

Key Concept: The responsible and judicious use of non-renewable resources to prevent pollution, biodiversity loss, and climate change

c) To extend their availability and reduce environmental impact
[Solution Description] Non-renewable resources are finite and cannot be replenished once depleted. Using them wisely helps in extending their availability, preventing environmental degradation, and mitigating adverse impacts on biodiversity and climate.

Key Concept: Implications of Uneven Distribution

d) It causes conflicts over resource access
[Solution Description] The uneven distribution of natural resources can lead to tensions and conflicts between countries as they compete for access and control over these resources. This competition may fuel disputes, trade restrictions, or even wars, as countries seek to secure their economic and strategic interests.

Key Concept: Deforestation and Its Implications

d) By increasing greenhouse gas concentrations
[Solution Description] Deforestation leads to the removal of trees that absorb carbon dioxide during photosynthesis. Without these trees, there is an increased concentration of greenhouse gases like carbon dioxide in the atmosphere, which contributes significantly to the greenhouse effect, thereby causing a rise in global temperatures.