HYDROLOGIC DATA COMPILATION FOR THE RIO CHAMA

BY ANGELA GREGORY

OBJECTIVE: To determine the hydrologic and physical characteristics of the Rio Chama Watershed in southern Colorado and northern New Mexico that would impact suspended sediment concentrations and bed load material in the Rio Chama.

RESULTS: The maps produced showed that the highest peaks were located along the eastern edges of the watershed. Hydrologic Soil Groups varied throughout the watershed with poorly drained soils occurring primarily on the west side and moderate draining soils on the east side. NRCS Soil Classification shows that gravelly silts, and clays are predominant throughout the watershed and do not provide enough information to explain why the west side of the watershed is poorly draining. Slope analysis was performed and showed high slopes on the western slopes of the watershed.

METHODS: Data was collected from the USGS Streamless Data Center, USGS NM Water Science Center, Resource Geographical Information System, and SSURGO. ArcMap, ArcScene, and Microsoft Excel were used to compile and derive data essential to the project. ANALYSIS: Data elevation models (DEM), HUC, streams, USGS gage locations, dam locations, vegetative cover, hydrologic soil group, NRCS soil classifications were used to describe the hydrologic characteristics and attributes that make up the Rio Chama watershed. Data were projected into NAD 1983.

CONCLUSION: A large amount of knowledge was gained simply from making maps that specify the vegetation types, hydrologic soil groups, topography, and NRCS soil classifications. Specifically, it was learned that the eastern side has high erodibility potential and could be a source of sediment for to the Rio Chama. Similarly, eastern portion of the watershed has some clay content along with high slopes and similarly could also act as a source of fine sediment. At this point, sediment sources are only speculative and it would be interesting to confirm the potential sources of sediment to the Rio Chama.