Broad overview of USGS research and monitoring designed to understand current changes in the context of prehistoric and recent earth processes, distinguishing between natural and human-influenced changes, and recognizing ecological and physical responses
Brief descriptions and links to major USGS programs at the state, regional, national, and international level for providing hydrologic information and for appraising the quantity, quality and location of the Nation's water resources.
Summer rains have remained steady over the past 20 years, but are less than historic highs. Temperature has increased, and while the farmland per person is decreasing, population growth has been offset with improved yields.
Long-term reduction in rainfall and increasing temperature threaten Chad's future food production prospects; combined with rapid population growth and zones of substantial conflict, increasing numbers of people will be at risk.
Summer rains have remained steady for the past 20 years, but are below the long-term average. Current population and agricultural trends indicate increasing yields have offset population expansion, keeping per capita cereal production steady.