Consider the following statements regarding 'Parabolic Dunes': 1. They form when sandy surfaces are partially covered with vegetation. 2. They are reversed barchans with wind direction being the same. 3. They have wings directed away from the wind direction. Which of the statements given above is/are correct?

The correct option is 1 and 2 only. Explanation Parabolic dunes are U-shaped or scoop-shaped mounds of sand that form in areas where vegetation covers parts of the sand. They are classified as aeolian (wind-driven) depositional landforms. Statement-wise Analysis: - Statement 1 is Correct: Parabolic dunes typically develop when sandy surfaces are partially covered with vegetation. The vegetation anchors the sand at the sides (wings), while the central part of the dune remains loose and is pushed forward by the wind. - Statement 2 is Correct: In terms of shape, parabolic dunes resemble barchans but are oriented in the opposite direction relative to the wind. Therefore, they are often described as "reversed barchans." - Statement 3 is Incorrect: Unlike barchans, where the wings (horns) point away from the wind (downwind), the wings of a parabolic dune point towards the wind direction (upwind). This occurs because the vegetation holds back the arms while the central sand migrates leeward. Key Takeaway: The primary distinction between a Barchan and a Parabolic dune is the orientation of their wings: Barchan wings point downwind (away from wind), whereas Parabolic dune wings point upwind (towards wind) due to vegetation anchoring.

Consider the following statements regarding 'Parabolic… - NCERT Class 11 Geography MCQ

NCERT Class 11 Geography — Chapter 5: Landforms and Their Evolution

mcqhard

Consider the following statements regarding 'Parabolic Dunes':

They form when sandy surfaces are partially covered with vegetation.
They are reversed barchans with wind direction being the same.
They have wings directed away from the wind direction.

Which of the statements given above is/are correct?

NCERT textbook question

From NCERT Fundamentals of Physical Geography · Page 61

Options

A1, 2 and 3
B1 only
C2 and 3 only
D1 and 2 only

Did you get this right?

Solution

The correct option is 1 and 2 only.

Explanation

Parabolic dunes are U-shaped or scoop-shaped mounds of sand that form in areas where vegetation covers parts of the sand. They are classified as aeolian (wind-driven) depositional landforms.

Statement-wise Analysis:

Statement 1 is Correct: Parabolic dunes typically develop when sandy surfaces are partially covered with vegetation. The vegetation anchors the sand at the sides (wings), while the central part of the dune remains loose and is pushed forward by the wind.
Statement 2 is Correct: In terms of shape, parabolic dunes resemble barchans but are oriented in the opposite direction relative to the wind. Therefore, they are often described as "reversed barchans."
Statement 3 is Incorrect: Unlike barchans, where the wings (horns) point away from the wind (downwind), the wings of a parabolic dune point towards the wind direction (upwind). This occurs because the vegetation holds back the arms while the central sand migrates leeward.

Key Takeaway:

The primary distinction between a Barchan and a Parabolic dune is the orientation of their wings: Barchan wings point downwind (away from wind), whereas Parabolic dune wings point upwind (towards wind) due to vegetation anchoring.

Your note

More from Chapter 5: Landforms and Their Evolution

With reference to 'Caves' in Karst regions, consider the following statements: 1. Water moves only vertically to dissolve the limestone. 2. Caves form where there are alternating beds of rocks with limestones or in massive limestone beds. 3. Caves having openings at both ends are called sinkholes. Which of the statements given above is/are correct?

medium

Which factor does NOT contribute to the formation of river meanders?

easy

With reference to the stages of landscape development by running water, consider the following statements: 1. In the youth stage, streams are few with poor integration and flow over original slopes. 2. In the mature stage, waterfalls and rapids dominate the landscape. 3. In the old stage, divides are sharp and steep. Which of the statements given above is/are correct?

medium

Consider the following statements regarding 'Low Sedimentary Coasts': 1. Rivers shorten their length by eroding coastal plains. 2. The coastline appears smooth with occasional incursions of water into the land. 3. Lagoons and tidal creeks are common. Which of the statements given above is/are correct?

medium

Which characteristic is NOT associated with the "Youth" stage of a river's course?

easy

Keep practising Chapter 5: Landforms and Their Evolution

Work through every question from this NCERT chapter.

Browse all NCERT Class 11 Geography chapters