grad ed ▁land , ▁making ▁excess ive ▁er os ion ▁one ▁of ▁the ▁most ▁significant ▁environmental ▁problems ▁world wide . ▁ ▁Int ensive ▁agricult ure , ▁def or est ation , ▁roads , ▁anth rop ogen ic ▁climate ▁change ▁and ▁urban ▁spraw l ▁are ▁amongst ▁the ▁most ▁significant ▁human ▁activities ▁in ▁regard ▁to ▁their ▁effect ▁on ▁stim ulating ▁er os ion . ▁However , ▁there ▁are ▁many ▁prevent ion ▁and ▁rem ed iation ▁practices ▁that ▁can ▁cur tail ▁or ▁limit ▁er os ion ▁of ▁vulner able ▁so ils . ▁ ▁Phys ical ▁processes ▁ ▁Rain fall ▁and ▁surface ▁run off ▁ ▁Rain fall , ▁and ▁the ▁surface ▁run off ▁which ▁may ▁result ▁from ▁ra inf all , ▁produces ▁four ▁main ▁types ▁of ▁soil ▁er os ion : ▁spl ash ▁er os ion , ▁sheet ▁er os ion , ▁r ill ▁er os ion , ▁and ▁g ul ly ▁er os ion . ▁S pl ash ▁er os ion ▁is ▁generally ▁seen ▁as ▁the ▁first ▁and ▁least ▁severe ▁stage ▁in ▁the ▁soil ▁er os ion ▁process , ▁which ▁is ▁followed ▁by ▁sheet ▁er os ion , ▁then ▁r ill ▁er os ion ▁and ▁finally ▁g ul ly ▁er os ion ▁( the ▁most ▁severe ▁of ▁the ▁four ). ▁ ▁In ▁spl ash ▁er os ion , ▁the ▁impact ▁of ▁a ▁falling ▁ra ind rop ▁creates ▁a ▁small ▁cr ater ▁in ▁the ▁soil , ▁e ject ing ▁soil ▁particles . ▁The ▁distance ▁these ▁soil ▁particles ▁travel ▁can ▁be ▁as ▁much ▁as ▁ 0 . 6