Northern Region, Nigeria patches of grass and sand, found in the northeast. In the Sahel region, rain is less than 20 inches (508 mm) per year and the Sahara Desert is encroaching. In the dry north-east corner of the country lies Lake Chad, which Northern Nigeria shares with Niger, Chad and Cameroon. Northern Nigeria is divided into 18 provinces: Kano, the largest of the provinces in terms of population and economy is in the North-Central part of the country. The Kano Native Authority an offshoot of the fula Kano Emirate inherited the ancient trade industries that fuelled the trans saharan trade with North
Far North Region, Cameroon the Mandara Mountains. The Mayo Kébi, Mayo Louti, and their tributaries form part of the Niger River basin. The Louti rises in the Mandaras, passing and swelling the Kébi in the North Province. The Kébi rises south of Yagoua and flows into western Chad. The province's other rivers are part of the Chad Basin. The El Beid River flows northwest from the Kalamalou National Park and forms the northernmost stretch of the border between Cameroon and Nigeria. The Mayo Tsanaga rises south and west of the El Béïd's source and moves eastward at the north of the Diamaré Depression. The