Enrique Vivoni is a hydrologist who is interested in the interactions of water in the lithosphere, biosphere and atmosphere. His current research focuses on land surface ecohydrological processes in the semiarid southwestern United States and northwestern Mexico, in particular during the summer monsoon season. Current field efforts include a small watershed study of ecohydrological interactions in the Sevilleta National Wildlife Refuge, a regional basin study of the hydroclimatological impact of vegetation greening in the Rio Sonora in Mexico, and the study of the short and long-term effects of vegetation changes on the hydrological response in basins of northern New Mexico. In these studies, field observations and remote sensing data are used in conjunction with a distributed model to explore the underlying hydrological mechanisms and provide relevant predictions at the watershed scale. This research involves data analyses of observations, numerical modeling using parallel computing, and synthesis activities to test relevant hypotheses.