Nigeria Sudan savannah is similar but with shorter grasses and shorter trees. Sahel savannah consists of patches of grass and sand, found in the northeast. In the Sahel region, rain is less than per year and the Sahara Desert is encroaching. In the dry northeast corner of the country lies Lake Chad, which Nigeria shares with Niger, Chad and Cameroon. Nigeria's Delta region, home of the large oil industry, experiences serious oil spills and other environmental problems, which has caused conflict. Waste management including sewage treatment, the linked processes of deforestation and soil degradation, and climate change or global warming are
Colony of Niger Tibesti Cercle ceded to Chad Colony in French Equatorial Africa, and in 1932, the colony of French Upper Volta was divided amongst its neighbors, with the Cercles of Dori and Fada N'gourma ceded to Niger Colony. Niger Colony officials, unlike neighboring Chad, remained loyal to the French Vichy government after 1940, and thus closed its southern border (to Nigeria) and eastern border until 1944. On 31 December 1946 the Military Territories of N'Guigmi and Agadez were ceded to Niger Colony, leaving only Bilma Cercle as the last military-run section of modern Niger. This area in the far north east only