▁a ▁ ▁segment ▁of ▁the ▁Beau fort ▁Sea ▁sh or eline ▁aver aged ▁ ▁per ▁year ▁from ▁ 1 9 5 5 ▁to ▁ 2 0 0 2 . ▁ ▁Flo ods ▁ ▁At ▁extremely ▁high ▁flows , ▁kol ks , ▁or ▁v ort ices ▁are ▁formed ▁by ▁large ▁volumes ▁of ▁rapidly ▁r ushing ▁water . ▁Kol ks ▁cause ▁extreme ▁local ▁er os ion , ▁pl uck ing ▁bed rock ▁and ▁creating ▁p oth ole - type ▁ge ographical ▁features ▁called ▁Rock - cut ▁bas ins . ▁Ex amples ▁can ▁be ▁seen ▁in ▁the ▁flo od ▁regions ▁result ▁from ▁gla cial ▁Lake ▁Miss ou la , ▁which ▁created ▁the ▁ch anne led ▁sc ab lands ▁in ▁the ▁Columbia ▁Bas in ▁region ▁of ▁eastern ▁Washington . ▁ ▁Wind ▁er os ion ▁ ▁Wind ▁er os ion ▁is ▁a ▁major ▁ge omorph ological ▁force , ▁especially ▁in ▁ar id ▁and ▁semi - ar id ▁regions . ▁It ▁is ▁also ▁a ▁major ▁source ▁of ▁land ▁de grad ation , ▁ev ap oration , ▁desert ification , ▁harm ful ▁air bor ne ▁dust , ▁and ▁c rop ▁damage — es pecially ▁after ▁being ▁increased ▁far ▁above ▁natural ▁rates ▁by ▁human ▁activities ▁such ▁as ▁def or est ation , ▁urban ization , ▁and ▁agricult ure . ▁ ▁Wind ▁er os ion ▁is ▁of ▁two ▁primary ▁vari eties : ▁def lation , ▁where ▁the ▁wind ▁pick s ▁up ▁and ▁car ries ▁away ▁loose ▁particles ; ▁and ▁ab ras ion , ▁where ▁surfaces ▁are ▁worn ▁down ▁as ▁they ▁are ▁struck