Historical changes in streamflows, channel morphology, and riparian vegetation of the Rio Grande downstream of Brownsville, Texas

The Rio GrandefRio Bravo drains an area of more than 440,300 square kilometers of Mexico and southwestern United States (Bartlett. 1984). The Rio Grande flows for 3,000 kilometers from its headwaters in the San Juan Mountains of southern Colorado to the Gulf of Mexico downstream of Brownsville, Texas. The "Rio," as it is often called, drains the southern Rocky Mountains of Colorado and northern New Mexico; the vast Chihuahuan Desert of southern New Mexico, northern Mexico, and southwestern Texas; ami the subtropical lower valley of southern Texas (fig. I).