COURSE 5443 ASSIGNMENT 2(SOLVED)

Course: Introduction to Environment (5443)           

      Semester: Spring, 2024

ASSIGNMENT 2 QUESTIONS QUESTIONS SOLVED

LEVEL : BS

ASSIGNMENT No.2

(Units: 5–9)

Q. 1 (a) Differentiate between the following terms:

i. Lakes, Ponds, and Reservoirs:

• Lakes:
  • Definition: Large, naturally occurring bodies of standing water that are typically deeper and have a larger surface area than ponds.
  • Characteristics: Lakes can vary greatly in size and depth. They often have distinct zones (littoral, limnetic, and profundal) and can support diverse aquatic ecosystems.
  • Example: Lake Superior in North America.
• Ponds:
  • Definition: Smaller, shallower bodies of standing water compared to lakes.
  • Characteristics: Ponds are usually less than 6 meters (20 feet) deep and can support simpler aquatic ecosystems. They often have more vegetation and a higher rate of evaporation relative to their size.
  • Example: Duck ponds in parks or small farm ponds.
• Reservoirs:
  • Definition: Artificially created lakes formed by damming rivers or streams to store water for various uses.
  • Characteristics: Reservoirs are designed for specific purposes such as water supply, irrigation, flood control, or hydroelectric power generation. Their size and depth can vary widely depending on the purpose and the river or stream being dammed.
  • Example: Hoover Dam Reservoir (Lake Mead) in the United States.

ii. Pollution and Deforestation:

• Pollution:
  • Definition: The introduction of harmful substances or products into the environment that cause adverse effects.
  • Types: Includes air pollution (e.g., from vehicle emissions), water pollution (e.g., from industrial waste), soil pollution (e.g., from pesticides), and noise pollution (e.g., from machinery).
  • Consequences: Pollution can lead to health problems, environmental degradation, and loss of biodiversity.
• Deforestation:
  • Definition: The large-scale removal of forests, often to clear land for agriculture, urban development, or logging.
  • Impacts: Deforestation leads to habitat loss, decreases biodiversity, disrupts water cycles, and contributes to climate change by increasing atmospheric carbon dioxide levels.
  • Consequences: It affects ecosystems, contributes to soil erosion, and reduces the earth’s capacity to absorb carbon dioxide.

iii. Infiltration and Percolation:

• Infiltration:
  • Definition: The process by which water on the surface enters and moves through the soil.
  • Characteristics: Infiltration rates depend on soil type, land use, and vegetation. It is the first step in the hydrological cycle that replenishes groundwater.
  • Example: Rainwater soaking into the soil.
• Percolation:
  • Definition: The downward movement of water through the soil and rock layers to reach the groundwater.
  • Characteristics: Percolation follows infiltration and involves the movement of water through soil and porous rock layers. It contributes to groundwater recharge.
  • Example: Water filtering through soil layers and reaching the aquifer.

iv. Nitrification and Carbon Cycle:

• Nitrification:
  • Definition: A microbial process in the nitrogen cycle where ammonia (NH₃) is converted into nitrites (NO₂⁻) and then into nitrates (NO₃⁻).
  • Process: Involves two main steps: ammonium oxidation by Nitrosomonas bacteria and nitrite oxidation by Nitrobacter bacteria.
  • Significance: Nitrification makes nitrogen available to plants in a usable form and is essential for soil fertility.
• Carbon Cycle:
  • Definition: The continuous exchange of carbon among the atmosphere, oceans, soil, and living organisms.
  • Process: Includes processes such as photosynthesis (plants absorb CO₂), respiration (release of CO₂ by animals and plants), decomposition (breakdown of organic matter), and combustion (burning fossil fuels).
  • Significance: Regulates Earth’s climate and supports life by recycling carbon through different forms.

v. Genetic Diversity and Ecosystem Diversity:

• Genetic Diversity:
  • Definition: The variety of genetic information within a single species or population.
  • Importance: Genetic diversity enables populations to adapt to changing environments and resist diseases. It is crucial for the long-term survival and evolution of species.
• Ecosystem Diversity:
  • Definition: The variety of ecosystems within a given region or the entire planet.
  • Importance: Ecosystem diversity supports different types of habitats, provides various ecosystem services, and contributes to overall biodiversity. It includes diverse ecosystems like forests, wetlands, and deserts.

(b) Write a note on Eutrophication:

• Eutrophication:
  • Definition: Eutrophication is the process by which a water body becomes enriched with nutrients, primarily nitrogen and phosphorus, leading to excessive growth of algae and other aquatic plants.
  • Causes: Often driven by runoff from agricultural fields, sewage discharge, and industrial waste, which increase nutrient levels in water bodies.
  • Consequences: Excessive algal growth can lead to hypoxia (low oxygen levels) in the water, harming aquatic life by reducing oxygen availability. It can also cause algal blooms that produce toxins harmful to both aquatic organisms and humans.
  • Management: Mitigation strategies include reducing nutrient runoff through better agricultural practices, wastewater treatment, and maintaining riparian buffers.

Q. 2 Write a detailed note on the following:

i. Biological Resources:

• Definition: Biological resources refer to the living organisms and ecosystems that provide essential goods and services to humans. This includes plants, animals, fungi, and microorganisms.
• Types:
  • Genetic Resources: Variability in genes within species that can be utilized for breeding and genetic improvement. Examples include crops and livestock breeds with desirable traits.
  • Species Resources: Individual species of plants, animals, and microorganisms used for food, medicine, and industrial applications. Examples include medicinal plants, food crops, and livestock.
  • Ecosystem Resources: Ecosystems provide services such as pollination, water purification, and soil fertility. Examples include forests, wetlands, and coral reefs.
• Importance: Biological resources are crucial for human survival and well-being. They contribute to food security, health care, and economic development. Conservation of these resources ensures sustainability and resilience against environmental changes.

ii. Ecosystem Services:

• Definition: Ecosystem services are the benefits that humans receive from ecosystems. These services are vital for sustaining human life and include various functions provided by natural systems.
• Categories:
  • Provisioning Services: These are the products obtained from ecosystems, such as food, fresh water, timber, and medicinal resources.
  • Regulating Services: These services help regulate ecosystem processes and include climate regulation, water purification, flood control, and disease regulation.
  • Cultural Services: These include non-material benefits such as recreational opportunities, spiritual enrichment, and aesthetic values.
  • Supporting Services: These are necessary for the production of all other ecosystem services and include nutrient cycling, soil formation, and primary production.
• Importance: Ecosystem services support human health, livelihoods, and quality of life. Protecting and maintaining these services is essential for sustainable development and addressing challenges like climate change and biodiversity loss.

Q. 3 What is the composition of the Hydrosphere? Discuss any three compartments of the hydrosphere in detail along with their importance.

• Composition of the Hydrosphere:
  • The hydrosphere encompasses all the water on Earth, including oceans, seas, rivers, lakes, glaciers, groundwater, and atmospheric water vapor. It constitutes about 71% of the Earth’s surface, with the majority being saltwater in the oceans and a small fraction as freshwater in glaciers, rivers, and lakes.
• Compartments of the Hydrosphere:
  1. Oceans:
     • Description: Oceans are the largest compartment of the hydrosphere, covering approximately 71% of Earth’s surface. They are divided into several major oceans: the Pacific, Atlantic, Indian, Southern, and Arctic Oceans.
     • Importance: Oceans play a crucial role in regulating Earth’s climate by storing and distributing heat. They support a vast array of marine life, influence weather patterns through evaporation and precipitation, and are a primary source of food and resources like fish and minerals.
  2. Glaciers and Ice Caps:
     • Description: Glaciers and ice caps are large masses of ice found in polar regions and high mountain ranges. They store about 68.7% of Earth’s freshwater.
     • Importance: Glaciers and ice caps are critical for maintaining global sea levels. They act as freshwater reservoirs, releasing water slowly into rivers and lakes. Their melting contributes to sea level rise, impacting coastal communities and ecosystems.
  3. Groundwater:
     • Description: Groundwater refers to water that exists beneath the Earth’s surface in soil pore spaces and rock formations. It includes aquifers, which are porous rock layers that store and transmit water.
     • Importance: Groundwater is a major source of drinking water for many regions, especially in arid and semi-arid areas. It supports agriculture through irrigation and helps maintain river flows during dry periods. Proper management is essential to prevent depletion and contamination of groundwater resources.

Q. 4 (a) Define mineral and rock. What are different types of minerals, discuss in detail?

• Mineral:
  • Definition: A mineral is a naturally occurring, inorganic solid with a definite chemical composition and a crystalline structure. Minerals are formed through geological processes and are the building blocks of rocks.
  • Characteristics: Minerals have specific physical properties, such as hardness, luster, color, streak, and cleavage. They are classified based on their chemical composition and crystal structure.
• Rock:
  • Definition: A rock is a naturally occurring, aggregate of one or more minerals or mineraloids. Rocks can also include organic materials and are classified based on their formation process and composition.
  • Types: Rocks are generally classified into three main categories based on their formation: igneous, sedimentary, and metamorphic.
• Types of Minerals:
  1. Silicates:
     • Description: Silicates are the most abundant group of minerals in the Earth’s crust, characterized by the presence of silicon and oxygen in their structure.
     • Examples:
       • Quartz: Common in many rocks, quartz is known for its hardness and resistance to weathering.
       • Feldspar: A group of minerals that are key components of granite and other igneous rocks. They include orthoclase and plagioclase.
     • Importance: Silicates form a major part of the Earth’s crust and are crucial in the formation of igneous and metamorphic rocks.
  2. Carbonates:
     • Description: Carbonates are minerals that contain carbonate ions (CO₃²⁻) in their structure.
     • Examples:
       • Calcite: Found in sedimentary rocks like limestone and marble, calcite is used in cement and lime production.
       • Dolomite: Contains calcium and magnesium carbonates and is used in construction and as a refractory material.
     • Importance: Carbonates are significant in sedimentary rock formation and in the carbon cycle.
  3. Oxides:
     • Description: Oxides are minerals where oxygen is combined with metals.
     • Examples:
       • Hematite: An iron oxide mineral that is a major ore of iron and is used in pigments.
       • Magnetite: Another iron oxide, it is magnetic and used in industrial applications and as a source of iron.
     • Importance: Oxides are important as ores of various metals and in various industrial processes.
  4. Sulfides:
     • Description: Sulfides are minerals in which sulfur is combined with metals.
     • Examples:
       • Pyrite: Known as “fool’s gold,” pyrite is a source of sulfur and used in sulfuric acid production.
       • Galena: A major ore of lead, galena is used in lead production and as a source of silver.
     • Importance: Sulfides are key sources of metals and have industrial applications.
  5. Halides:
     • Description: Halides are minerals where halogen elements (fluorine, chlorine, bromine, iodine) are combined with metals.
     • Examples:
       • Halite: Commonly known as rock salt, used for seasoning and de-icing roads.
       • Fluorite: Used in the manufacture of aluminum, gasoline, and uranium fuel.
     • Importance: Halides are important in various industrial processes and in the manufacture of chemicals.
  6. Native Elements:
     • Description: Native elements are minerals composed of a single element.
     • Examples:
       • Gold: Valued for its use in jewelry and electronics.
       • Copper: Used extensively in electrical wiring and plumbing.
     • Importance: Native elements are significant for their economic value and practical applications.

Q. 4 (b) Write a brief note on Pothwar Plateau.

• Pothwar Plateau:
  • Location: The Pothwar Plateau is a region located in the northern part of Pakistan, encompassing parts of Punjab and Khyber Pakhtunkhwa provinces. It lies between the Indus River to the west and the Jhelum and Chenab rivers to the east.
  • Geology and Geography: The plateau is characterized by its arid and semi-arid climate, with rocky and rugged terrain. It is composed mainly of sedimentary rocks, including sandstone, limestone, and shale. The region has a series of low hills and interspersed valleys.
  • Climate: The Pothwar Plateau experiences a continental climate with hot summers, cool winters, and irregular rainfall. The average annual precipitation is relatively low, making the region prone to droughts.
  • Economy: Agriculture is a significant part of the local economy, with crops like wheat, barley, and pulses being grown. The plateau also has deposits of minerals such as gypsum, limestone, and salt, which are extracted and used locally.
  • Historical Significance: The region has historical importance, with ancient ruins and archaeological sites that reflect its historical and cultural heritage. It has been a part of various civilizations and empires throughout history.

Q. 5 What is an island? Discuss important islands of Pakistan in detail.

• Island:
  • Definition: An island is a piece of land that is completely surrounded by water. Islands can vary in size from small islets to large landmasses and can be found in oceans, seas, rivers, and lakes.
  • Types: Islands are classified into several types, including oceanic islands (formed by volcanic activity), continental islands (part of the continental shelf), and river islands (formed by sediment deposition in rivers).
• Important Islands of Pakistan:
  1. Sina Island:
     • Location: Located in the Arabian Sea, off the coast of Karachi.
     • Features: Sina Island is one of the smaller islands in the Karachi Archipelago and is used for various purposes, including fishing and recreational activities.
  2. Badh Island:
     • Location: Situated in the Arabian Sea, south of Karachi.
     • Features: Badh Island is a larger island and has significant economic and ecological value. It is used for salt production and has unique coastal and marine ecosystems.
  3. Manora Island:
     • Location: Close to the city of Karachi, near the mouth of Karachi Harbour.
     • Features: Manora Island is known for its historical lighthouse, scenic beaches, and as a popular spot for tourism. The island is part of the Karachi Archipelago and plays a role in maritime navigation.
  4. Astola Island:
     • Location: Located in the Arabian Sea, about 25 kilometers southeast of the city of Pasni in Balochistan.
     • Features: Astola Island, also known as the “Island of the Seven Hills,” is the largest island in Pakistan. It is a protected area known for its unique biodiversity, including various species of birds, reptiles, and marine life. The island is significant for conservation and research purposes.
  5. Churna Island:
     • Location: Situated in the Arabian Sea, near the Karachi coastline.
     • Features: Churna Island is known for its natural beauty and marine life. It is a popular destination for snorkeling and diving, with rich coral reefs and diverse underwater species.
  6. Kachhi Island:
     • Location: Found in the Indus River near the city of Sukkur.
     • Features: Kachhi Island is a river island formed by sediment deposition. It supports local agriculture and is part of the river’s dynamic ecosystem.