The Sudans Nile within the Sudans has no significant tributaries. The amount of rainfall increases towards the south. In the north there is the very dry Nubian Desert; in the south there are swamps and rainforest. The Sudans’s rainy season lasts for about three months (July to September) in the north, and up to six months (June to November) in the south. The dry regions are plagued by sandstorms, known as haboob, which can completely block out the sun. In the northern and western semi-desert areas, people rely on the scant rainfall for basic agriculture and many are nomadic, travelling with their
Amargosa Desert Death Valley to the west, and Yucca Mountain and the Nellis Air Force Range to the east. The Amargosa Desert is an arid desert habitat and an ecotone between the northern Great Basin and southern Mojave Desert ecosystems and biogeography regions. The seasonal Amargosa River course runs through the desert, with the rare Shoshone pupfish in nearby Amargosa Pupfish Station of the Desert National Wildlife Refuge Complex. It is not known when the first humans settled in the Amargosa Desert. Ancient campsites have been found that date back at least 10,000 years, to the end of the last ice age.