The Water Resources Science Program is designed to train students broadly in water resources while maintaining an intellectual affiliation with a secondary field. Allied fields include ecology, forest science, geology, oceanography, atmospheric sciences, climatology, geomorphology, soil physics, environmental science, geochemistry, public health, and microbiology. Many of these scientific disciplines now have significant overlap with hydrology, and demand has increased for scientists trained in these areas to command a knowledge of hydrology.<br><br>Increasing knowledge of connections between the biosphere and the hydrosphere are driving the emergence of the field of ecohydrology. Geologists have long been concerned with hydrology, and most groundwater issues require a reasonably sophisticated knowledge of geology. Problems in global change are increasingly recognized as linked to the land surface through freshwater runoff into the world's oceans and evapotranspiration. Many environmental problems require training in both hydrology and other areas of science.