Q161. An Urban Heat Island (UHI) refers to a phenomenon where:
Environmental and Ecological Changes and Impact Assessment: RAS Prelims MCQs
168 RAS Prelims MCQs on environmental and ecological changes and impact assessment cover ecosystem concepts, pollution, climate and environmental law. Ecotones, decomposers, primary productivity, secondary pollutants, the greenhouse effect, the EIA Notification 2006, the Environment (Protection) Act 1986 and the Aravalli mining ban are asked as definitions, laws and statements.
Practice questions based on the RPSC RAS Prelims syllabus. They follow the exam pattern but are not past-paper questions.
Showing 161–168 of 168 questions
Q162. Which of the following properties of urban building materials contributes heavily to the UHI effect?
Explanation
The types of materials used to build modern cities play a major role in how much heat is absorbed from the sun. Common surfaces like dark asphalt and concrete have a low ability to reflect sunlight. Instead, they soak up the energy and store it for a long time. This high capacity for holding heat means that city surfaces stay much warmer than natural areas, especially during the night when the stored energy is released.
Q163. The lack of vegetation in urban areas exacerbates the heat island effect primarily due to the reduction of:
Explanation
Natural landscapes with plenty of trees and plants help to keep the air cool through a process that involves the movement of water from the leaves into the atmosphere. When large areas of land are paved over and covered with buildings, this natural cooling effect is lost. The absence of vegetation means that less moisture is released into the air, which contributes significantly to the higher temperatures that are characteristic of most urban environments.
Q164. What is the impact of the "urban canyon effect" generated by tall buildings?
Explanation
In cities with many tall buildings located close together, the narrow streets between them can create a unique microclimate. During the day, these deep spaces trap incoming solar radiation, and the surfaces of the buildings continue to release heat long into the night.
Q165. Consider the following strategies to mitigate the Urban Heat Island effect:
I. Installing green roofs
II. Using cool pavements with high albedo
III. Increasing urban tree canopy
IV. Expanding asphalt surface parking lots
V. Promoting the use of energy-efficient appliances
Which of the above statement(s) is/are correct?
I. Installing green roofs
II. Using cool pavements with high albedo
III. Increasing urban tree canopy
IV. Expanding asphalt surface parking lots
V. Promoting the use of energy-efficient appliances
Which of the above statement(s) is/are correct?
Explanation
Several effective strategies can be used to reduce the higher temperatures found in many cities. These include covering rooftops with vegetation, using light-colored materials for pavements that reflect more sunlight, and significantly increasing the number of trees and parks. Improving the efficiency of buildings and vehicles also helps by reducing the amount of waste heat released. Together, these actions can make urban areas more comfortable, reduce energy demand, and improve public health.
Q166. How does the Urban Heat Island effect impact local environmental pollution?
Explanation
Higher temperatures in urban areas can make environmental pollution even worse. The heat can speed up the chemical reactions that form harmful ground-level ozone from common city emissions. Furthermore, as people use more electricity for air conditioning to stay cool, the power plants that provide that energy often release more pollutants into the air. This combination of heat and smog creates a significant health risk for urban populations during periods of extreme weather.
Q167. Anthropogenic heat, a contributor to UHI, originates from:
Explanation
A significant amount of the extra heat found in cities comes from the daily activities of the people who live and work there. This includes the energy released by the engines of cars and buses, as well as the heat discarded by air conditioning and heating systems from buildings. Even industrial processes and common appliances contribute to this localized warming. Together, these human sources add a substantial amount of thermal energy to urban environments.
Q168. Rapid urbanization often leads to the sealing of soil surfaces with impermeable materials. This directly causes:
Explanation
Covering the ground with materials like asphalt and concrete prevents rainwater from soaking into the soil. Instead of replenishing the local groundwater, the water stays on the surface and flows rapidly into drains and nearby streams. During heavy rain, this large volume of fast-moving water can easily overwhelm the drainage systems, leading to frequent and severe flooding in urban areas. This problem also reduces the amount of water available for ecosystems.Answer key for these questions
| Q | Correct answer |
|---|---|
| 161 | (a) Urban areas warmer than rural areas |
| 162 | (b) Low albedo and high heat capacity |
| 163 | (b) Evapotranspiration |
| 164 | (a) Traps radiation and reduces wind speed |
| 165 | (a) I, II, III and V |
| 166 | (d) Increases cooling energy and emissions |
| 167 | (c) Activities such as vehicles and AC use |
| 168 | (b) Increased flooding and surface runoff |
Key facts from Environmental and Ecological Changes and Impact Assessment
- An ecosystem is made of interacting organisms and their physical environment; an ecotone is a zone of transition between ecosystems.
- Saprotrophs convert complex organic matter into simple substances; gross primary productivity is the rate at which producers create organic matter.
- Plants release water vapour through transpiration.
- Ground-level ozone is a secondary pollutant; CO, SO₂ and PM10 are primary pollutants.
- The greenhouse effect is the trapping of heat by atmospheric gases.
- Category B2 projects are exempt from public consultation under the EIA Notification 2006; the Supreme Court banned mining in the Aravalli range in Haryana and Rajasthan.
Frequently asked questions
How many RAS Prelims practice MCQs are there on Environmental and Ecological Changes and Impact Assessment?
This page has 168 practice MCQs on Environmental and Ecological Changes and Impact Assessment (Health, Environment and Agriculture). Each has the correct answer, and most have an explanation.
What is a secondary pollutant?
A pollutant that is not emitted directly but forms in the air from primary pollutants. Ground-level ozone is the standard example, formed when nitrogen oxides and volatile organic compounds react in sunlight.
What is an ecotone?
A zone of transition between two different ecosystems, such as the area between a forest and a grassland. It often has more species than either neighbour because it has species of both.
Which projects are exempt from public consultation under EIA 2006?
Category B2 projects, which have less environmental impact. Category A and B1 projects need public consultation as part of the clearance process, which is the main way local people are heard.