Chad Basin demand for ivory, but stocks have since recovered. The seasonal Korama River in the south of Niger does not reach Lake Chad. Nigeria includes two sub-basins that drain into Lake Chad. The Hadejia - Jama'are - Yobe sub-basin in the north contains the Hadejia and Jama'are rivers, which supply the Hadejia-Nguru wetlands. They converge to form the Yobe, which defines the border between Niger and Nigeria for , flowing into Lake Chad. About of water reaches Lake Chad annually. Construction of upstream dams and growth in irrigation have reduced water flow, and the floodplains are drying up. The Yedseram -
Rail transport in Chad Imperial expansionist policy known as Mittelafrika. In the 1950s a line through Chad from Port Sudan to Nigeria was proposed but opposed by Chad governmental organisations. In 1958 plans for a line from Cameroon the "Société Civile d'Études du Chemin de Fer Douala-Tchad" (SEDOT) was formed, and continued planning led to start of construction in 1964 - the line was constructed as far as Ngaoundéré in Cameroon (the Trans-Cameroon Railway, completed 1975.). Initial plans were for an extension to Moundou in Chad, but this was not completed. In 1959 a multinational agency, the "Agence Transéquatoriale des Communications" (ATEC) was formed