San Pedro RiverThis basin and range river has been the focus of significant research over the last several decades. The San Pedro is one of the last free flowing rivers in the American Southwest and has been named on of the 10 Last Great Places by the Nature Conservancy (TNC). TNC has a significant presence in the basin most significantly as a key member of the Upper San Pedro Partnership . The parnership is dedicated to preserve the San Pedro while also maintaing the viable opewration of Fort Huachuca a major military installation in the basin. My groups work in the basin is focused on the biogeochemical processes that control water quality in this and other similar desert rivers. As part of this work and in relation to water sustainability within the system the watershed biogeochemistry research group is also focused on where water in the river comes from with recent research focusing on the role of floods and stored groundwater that derives from floods. Critically it appears that as much as half of the water present in the river derives from flood events waters see Baillie et al 2007.
Santa Cruz River is the river that flows through Tucson. For much of its length the river is ephemeral. Where the river does flow it is generally supported by effluent release from Tucson or from Nogales, the twin border city in Arizona and Sonora. This effluent dominance creates a strong clogging layer in the bed of the stream that prevents recharge of the underlying aquifer. This layer only appears to be removed by large stroms that scour the stream bed. For more information see here.
Hassayampa Preserve Hassayampa literally translated from the original Yavapi languag means upside down river. An appropriate name as little more than 2 km of this river actually flow above ground. The preserve offers and end-member sort of soutwhestern riparian system as the recharge that suplies baseflow to the perrenial reach appears to derive entirely from a few large floods.
Bill Williams River The Bill Williams River in western Arizona offers another superb field site to conduct investigations of the interaction between surface water floods and the lagegd groundwater stroage that derives from floods. Notably the Alamo Dam is being used by the United States Army Corps of Engineers in cooperation with a wide number of agencies and stakeholders to conduct controlled releases from the dam to manage the downstream corridor for riparian system benchmarks and biodiversity. The downstream reach is entirely dependant on flood flows for sustained groundwater that supports the perrenial reach of the river that feeds the Bill Williams National Wildlife Refuge.
Niwot Ridge LTER is located in the Colorado Front Range of the Rocky Mountains. The research site contains both the ridge and Green Lakes Valley which has been biogeochemically gauged for neraly 30 years. Tthis represents one of the longest high elevation biogeochemical data sets in the world. Research work here focuses on better understanding the sources and flowaths of water within the basin over time.
Santa Catalina Mountains Observatory This series of research sites spans a nearly 2000 m eleveation span from Tucson to the top of the Santa Catalina Mountains. Thre major sets of paired catchments across the elevation gradient are being intesnively studied. The lower eleveation site is in Arizona high chaparral, the mid elevation site is in oak and pinyon juniper, while the highest elevation sites are in ponderosa pine and mixed conifer forest. Each elevation has one catchment on granite and catchment on schist parent material.
Valles Caldera and Jemez River Observatory This research site is located in northern New Mexico. This site and the Santa Catalinas observatory are both funded by the National Science Foundations Critical Zone Observatory Program. The Valles provides a comparison of Rhyollitic terrain with the granite and schist terrain of the Catalinas the Valles are also higher and drier than the Catalinas and subject to more interannual precipitation variability
San Dimas Experimental Forest The experimental forest dates back to 1933. Located in the San Gabriel mountains of southern California much of the work on the fire-flood-debris flow sequence was originally completed at this research site. Similarly seminal papers on the imapcts of atmospheric deposition from southern California's polluted air mass were also compleeted here. My groups work here focuses on udnerstanding post fire hydrology and the influence of vegetation and geology on the hydrologic and biogeochemical response of these systems.