Question 1

Q1: (i) In which of the following stages of landform development, downward cutting is dominated? (a) Youth stage (b) Late mature stage (c) Early mature st...

Accepted Answer

(a) Youth stage In the youth stage of landscape evolution by running water, streams are vigorous and flow over steep gradients. The text states, "In the early stages, down-cutting dominates during which irregularities such as waterfalls and cascades will be removed."

Question 2

Q2: (ii) A deep valley characterised by steep step-like side slopes is known as (a) U-shaped valley (b) Gorge (c) Blind valley (d) Canyon

Accepted Answer

(d) Canyon The text defines a canyon as being "characterised by steep step-like side slopes." It also notes that canyons commonly form in horizontally bedded sedimentary rocks.

Question 3

Q3: (iii) In which one of the following regions the chemical weathering process is more dominant than the mechanical process? (a) Humid region (b) Limesto...

Accepted Answer

(b) Limestone region The text states that in rocks like limestones or dolomites, "surface water as well as groundwater through the chemical process of solution and precipitation deposition develop varieties of landforms." This process of solution is a form of chemical weathering.

Question 4

Q4: (iv) Which one of the following sentences best defines the term 'Lapies'? (a) A small to medium sized shallow depression (b) A landform whose opening...

Accepted Answer

(d) An irregular surface with sharp pinnacles, grooves and ridges The text describes that after the surface of limestone is eaten away by pits and trenches, it leaves the surface "extremely irregular with a maze of points, grooves and ridges or lapies."

Question 5

Q5: (v) A deep, long and wide trough or basin with very steep concave high walls at its head as well as in sides is known as: (a) Cirque (b) Glacial valle...

Accepted Answer

(a) Cirque A cirque is defined in the text as a "deep, long and wide troughs or basins with very steep concave to vertically dropping high walls at its head as well as sides." They are the most common landforms in glaciated mountains.

Question 6

Q1: (i) What do incised meanders in rocks and meanders in plains of alluvium indicate?

Accepted Answer

Incised meanders cut deep into hard rocks, indicating that a river with a steep gradient has been actively eroding downwards, a sign of a youthful or rejuvenated river. Meanders in plains of alluvium are formed on gentle slopes by lateral erosion and deposition, indicating a mature or old stage of r...

Question 7

Q2: (ii) Explain the evolution of valley sinks or uvalas.

Accepted Answer

Valley sinks, or uvalas, are landforms found in karst (limestone) topography. They evolve when multiple, individual sinkholes and dolines form close to one another. Over time, due to the slumping of materials along their margins or the collapse of the roofs of underlying caves, these separate depres...

Question 8

Q3: (iii) Underground flow of water is more common than surface run-off in limestone areas. Why?

Accepted Answer

Underground water flow is more common in limestone areas because limestone is rich in calcium carbonate, which is easily dissolved by carbonated rainwater. This chemical process of solution creates and enlarges cracks, joints, and bedding planes, allowing surface water to easily percolate downwards...

Question 9

Q4: (iv) Glacial valleys show up many linear depositional forms. Give their locations and names.

Accepted Answer

Glacial valleys contain several linear depositional forms made of glacial till. These include:    Lateral Moraines: Ridges along the sides of the valley, parallel to the glacier's flow.    Medial Moraines: A ridge in the center of the valley, formed where two glaciers merge. *   Eskers: Sinuous ridg...

Question 10

Q5: (v) How does wind perform its task in desert areas? Is it the only agent responsible for the erosional features in the deserts?

Accepted Answer

Wind performs its task in deserts through deflation (lifting and removing dust), abrasion (sandblasting rock surfaces), and impact. However, wind is not the only agent responsible for erosional features. The text clearly states that many desert features also owe their formation to mass wasting and t...

Question 11

Q1: (i) Running water is by far the most dominating geomorphic agent in shaping the earth's surface in humid as well as in arid climates. Explain.

Accepted Answer

Running water is the most dominant geomorphic agent in both humid and arid climates, though its mode of action differs. In humid regions, which receive abundant rainfall, running water is the primary agent of land degradation. It operates as both overland sheet flow and linear flow in streams and ri...

Question 12

Q2: (ii) Limestones behave differently in humid and arid climates. Why? What is the dominant and almost exclusive geomorphic process in limestone areas an...

Accepted Answer

Limestones behave differently in humid and arid climates primarily due to the availability of water, which is the key agent in their chemical weathering. Limestone is composed mainly of calcium carbonate, which is highly soluble in carbonated water (rainwater that has absorbed carbon dioxide from th...

Question 13

Q3: (iii) How do glaciers accomplish the work of reducing high mountains into low hills and plains?

Accepted Answer

Glaciers reduce high mountains into low hills and plains through immense and prolonged erosion. The sheer weight of the ice causes tremendous friction and pressure at its base, enabling it to drastically alter the landscape through two main processes: plucking and abrasion.    Plucking: The glacier...

Question 14

Q1: If landform is a small to medium sized part of the surface of the earth，what is a landscape？

Accepted Answer

A landscape is a large tract of the earth's surface that is composed of several related landforms. While a landform is a single feature with its own shape, size, and materials, a landscape is the broader picture formed by the combination of these individual landforms.

Question 15

Q2: What are the two important aspects of the evolution of landforms？

Accepted Answer

Based on the text, the two important aspects of the evolution of landforms are: 1.  Transformation of one landform into another: This involves a part of the earth's surface changing from one type of landform to a different one over time due to geomorphic processes. 2.  Transformation of individual l...

Question 16

Q3: Is complete reduction of relief of a high land mass possible?

Accepted Answer

Complete reduction of the relief of a high landmass is not entirely possible according to the text. Through prolonged stream erosion, the landscape is lowered and flattened into a lowland of faint relief called a peneplain (an 'almost plain'). However, some low, resistant remnants of rock, called mo...

Question 17

Q4: In what way do natural levees differ from point bars?

Accepted Answer

Natural levees and point bars differ in their location and formation:    Location: Natural levees are low, linear ridges found along both banks of large rivers. Point bars are found specifically on the concave (inner) side of meanders.    Formation: Natural levees are formed from coarse deposits lef...

Question 18

Q5: What are the basic differences between glacial valleys and river valleys?

Accepted Answer

The basic differences between glacial valleys and river valleys are their shape and formation:    Shape: Glacial valleys are characteristically trough-like and U-shaped, with broad floors and steep, smooth sides. In contrast, river valleys, especially in their youthful stage, are typically V-shaped...

Question 19

Q6: Distinguish between river alluvial plains and glacial outwash plains.

Accepted Answer

River alluvial plains and glacial outwash plains are both depositional landforms but differ in their formative agent and composition:    River Alluvial Plains (Floodplains): These are formed by the deposition of fine-sized materials like sand, silt, and clay by a river, especially during floods. The...

Question 20

Q7: What is the difference between till and alluvium?

Accepted Answer

Till and alluvium are both types of sediment deposits, but they differ based on the agent of deposition and their characteristics:    Till: This is debris deposited directly by melting glaciers. It is unassorted, meaning it contains a mixture of coarse and fine materials, and the rock fragments with...

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