Niger is a landlocked country in Western Africa, named after the Niger River. Niger is bordered by Libya to the northeast, Chad to the east, Nigeria and Benin to the south, Burkina Faso and Mali to the west, and Algeria to the northwest. It is the largest country in West Africa, with over 80 percent of its land area covered by the Sahara Desert. Niger is a developing country, and is consistently one of the lowest-ranked in the United Nations' Human Development Index; it was ranked last at 188th for 2014. Much of the non-desert portions of the country are threatened by periodic drought and desertification. The economy is concentrated around subsistence and some export agriculture clustered in the more fertile south, and the export of raw materials, especially uranium ore. Niger faces serious challenges to development due to its landlocked position, desert terrain, high fertility rates and resulting overpopulation without birth control, poor education and poverty of its people, lack of infrastructure, poor health care, and environmental degradation. Environmental issues in Niger include destructive farming practices as a result of population pressure, as well as illegal hunting, bush fires in some areas and human encroachment upon the flood plains of the Niger River for paddy cultivation.