▁by ▁air bor ne ▁particles ▁carried ▁by ▁wind . ▁De fl ation ▁is ▁divided ▁into ▁three ▁categories : ▁( 1 ) ▁surface ▁cre ep , ▁where ▁larger , ▁heav ier ▁particles ▁slide ▁or ▁roll ▁along ▁the ▁ground ; ▁( 2 ) ▁salt ation , ▁where ▁particles ▁are ▁lifted ▁a ▁short ▁height ▁into ▁the ▁air , ▁and ▁b ounce ▁and ▁salt ate ▁across ▁the ▁surface ▁of ▁the ▁soil ; ▁and ▁( 3 ) ▁susp ension , ▁where ▁very ▁small ▁and ▁light ▁particles ▁are ▁lifted ▁into ▁the ▁air ▁by ▁the ▁wind , ▁and ▁are ▁often ▁carried ▁for ▁long ▁distances . ▁Salt ation ▁is ▁responsible ▁for ▁the ▁majority ▁( 5 0 – 7 0 %) ▁of ▁wind ▁er os ion , ▁followed ▁by ▁susp ension ▁( 3 0 – 4 0 % ), ▁and ▁then ▁surface ▁cre ep ▁( 5 – 2 5 %). ▁Sil ty ▁so ils ▁tend ▁to ▁be ▁the ▁most ▁affected ▁by ▁wind ▁er os ion ; ▁s ilt ▁particles ▁are ▁relatively ▁easily ▁det ached ▁and ▁carried ▁away . ▁ ▁Wind ▁er os ion ▁is ▁much ▁more ▁severe ▁in ▁ar id ▁areas ▁and ▁during ▁times ▁of ▁dr ought . ▁For ▁example , ▁in ▁the ▁Great ▁Pla ins , ▁it ▁is ▁estimated ▁that ▁soil ▁loss ▁due ▁to ▁wind ▁er os ion ▁can ▁be ▁as ▁much ▁as ▁ 6 1 0 0 ▁times ▁greater ▁in ▁dr ought ▁years ▁than ▁in ▁wet ▁years . ▁ ▁Mass ▁movement ▁ ▁Mass ▁movement ▁is ▁the ▁down ward ▁and ▁out ward ▁movement ▁of ▁rock ▁and ▁sed iments ▁on ▁a ▁s