Drought and desertification are closely related phenomena. Persisting over months or years, drought can affect large areas and may have serious environmental, social and economic impacts. While drought is a natural phenomenon, whose impacts can be exacerbated by human activities that are not adapted to the local climate, land degradation is the process of turning fertile land into less or non-productive land. In extreme cases in drylands this is called desertification. Land degradation and desertification are complex phenomena driven by un-adapted human activity in combination with land and climatic constraints. Inappropriate land use, such as monocultures, and unsustainable land management practices, such as deforestation, unsuitable agricultural practices and overexploitation of water resources), can cause land degradation that can be further aggravated by drought.
According to Geology, there's a theory which held that surface, mountains, lakes, were created by suddenly because of great catastrophes like earthquakes and floods.
