Pre-monsoon rainfall in Karnataka and Kerala is known as mango shower (also known as April rains or summer showers). It helps in the ripening of mangoes.
The Thermal concept of the origin of monsoon was given by noted astronomer Halley. But there were some faults. Halley overlooked the Coriolis effect and the concept of the passing of latent heat through water vapour.
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.