The useful steps to prevent soil erosion are Afforestation, Contour Ploughing, Prohibition of shifting cultivation, Flood control, Restoration of long fallow, reclamation of alkaline and saline soil.
The correct matches are Vajrai Waterfall- Urmodi river (Maharashtra), Barehipani Falls- Budhabalanga River (Odisha), Dhuandhar Falls- Narmada (Madhya Pradesh), Kunchikal Falls- Varahi river (Karnataka).