WIND Geography

Standard: VIII

Created by,M.Kohila, M.A. M.Phil., B.A.(Eng),B.Ed.,B.A.(His)

S.M.R.V.H.S.S.,VADASERY,

NAGERCOIL,KANYAKUMARI DISTRICT,

TAMILNADU,INDIA

LEARNING OBJECTIVES

1.Knows that wind is relatively insignificant erosional agent.

2. Learns about the causes for sand storms and dust storms.

3.Undersands the formation of sand dunes.

ContentSl.No Content Slide No.

1 Wind-Introduction 5

2 Wind Erosion 6

2.1 By deflation 6

2.2 By abrasion 6

3. Wind Transportation 7

3.1 Bed Loads - Sand storms

3.2 Suspended Load – Dust storms

4. Wind Deposition

4.1 Sand dunes

4.1.1 Formation of a dune

4.1.2 Barchan dunes

4.1.3 Transverse Dunes

4.1.4 Longitudinal Dunes

4.2 Loess

Air that moves across the earth’s surface is called wind.

Wind

Wind erosionWind erosion is effective in arid and semiarid areas.In humid places moisture bind particles together and vegetation anchor the soil . So wind erosion is negligible.For, wind to be effective ,dryness and scandy vegeation are prerequisites.Wind may pick up, transport, and deposit.

Works of windWind works in two ways to erode the

materials. They are a. By deflation and 2. by

abration

By Abration - Ventifacts Blow outBy deflation -

புடை�த்தெ�டுத்�ல் - ஊதுபள்ளங்கள் உரா�ய்ந்துதே�ய்த்�ல்-பட்டை�க்கற்கள்

Bed Loads Sand Storm

Dust storm Barchan dune

Longitudinal duneTransverse dune

Loess

Loess and yellow river in China

Desert in central Asia

Wind Erosion – Land forms

The end