This site houses collection of projects, data, and methods centering on the use of hydroinformatics, riverscape ecology, and watershed science to improve decision making and management of the watersheds in California's Sierra Nevada.
Welcome to our Sierran Strategies applied research group within the Center for Watershed Sciences. We are a diverse group, consisting of ecologists, engineers, hydrologists, and the like, all dedicated to developing and answering pressing questions in watershed science with a focus on the Sierra Nevada. We have four broad areas of collaboration:
1) hydrologic connectivity -- many pressing questions exist with respect to the longitudinal connectivity of Sierran water bodies, how connectivity occurs and is or can be managed, and at what spatial and temporal dimensions connectivity has relevant ecological ramifications. Additional measures of connectivity, such as vertical and lateral dimensions, are also included here, with examples such as meadow restoration and hydrologic budget studies and our many Cosumnes River seasonal floodplain studies.
2) scale integration -- vertical integration of research performed at nested spatial scales is complex, but increasingly important to improve our knowledge base and make meaningful recommendations for management. We are challenged to both model landscapes (or entire mountain ranges) and perform empirical observations at the site scale. To date, integrating across the range of spatial scales has proven challenging, but we are beginning to do so in a variety of ways, such as regional scale stream temperature modeling with instrumentation in selected long term monitoring locations.
3) regulated versus unregulated systems -- a fundamental strength is our ability to compare and contrast biotic and abiotic components of regulated and unregulated systems throughout the Sierra Nevada. Not only do these analyses help bridge the two areas of research above, but in effect these systems allow us to perform watershed scale experimentation, ala a before-after control-impact type studies, to better isolate the effects of management and the role of the natural flow regime in structuring river systems. While we have largely focused on forks of the Yuba and American Rivers to date, we have started to include others, such as tributaries of the Tuolumne River into our portfolio of rivers.
4) climate change, vulnerability, and adaptation -- the foremost challenge for the management of the Sierra Nevada's water supply and aquatic ecosystems is understanding the spatial and temporal dimensions of climate change, identifying and quantifying degrees of vulnerability to ecosystems and infrastructure, and crafting sound adaptation strategies that will best sustain ecosystem services.
On March 18, 2011, the journal Marine & Freshwater Research, published by Australia's national science agency CSIRO (Commonwealth Scientific and Industrial Research Organisation), issued a special compendium on Conservation Management of Rivers and Wetlands under Climate Change. Scientists from the UC Davis Center for Watershed Sciences were invited to contribute to this international effort to bring attention to the combined impacts of climate altered hydrology and ecosytem response to water management actions. After rigorous peer review, a paper contributed by Dr. Joshua Viers and David Rheinheimer, a Doctoral Candidate in the Departement of Civil & Environmental Engineering, was selected for the special issue. Their contribution Freshwater conservation options for a changing climate in California’s Sierra Nevada.
A key team member of the Center for Watershed Sciences -- Scott Ligare, a graduate student in Civil & Environmental Engineering -- participated in a recreation flow study on the Middle Fork American River.
Dr. Sarah Null presented her research on river temperature impacts of climate warming in California’s Sierra Nevada Mountains at DISCCRS from March 13 – 20 at Saguaro Ranch in Mesa, Arizona. The aim of DISCCRS (DISsertations initiative for the advancement of Climate Change ReSearch) is to foster interdisciplinary work by connecting young researchers to develop creative solutions to problems relating to climate change.
This applied workshop -- Water Management and the Tuolumne River -- featuring analyses of contemporary environmental problems in a multidisciplinary fashion. Students will be exposed to both environmental science and policy, tackling some of the toughest issues facing California: water resources, multiple downstream demands, and climate change adaptation. By using the Tuolumne River as a case study, students had the opportunity to learn about the history and future of this landmark river in our nation's history.
The headwaters of the Tuolumne River are located in the central Sierra Nevada, forming the northern portion of Yosemite National Park, and its waters ultimately flow through the Hetch Hetchy Valley to the City of Modesto and the San Joaquin River. The uniqueness of the Tuolumne River is bound in its history, its environmental setting, and its modern socioeconomic importance. The damming of the Tuolumne River at Hetch Hetchy is a landmark moment in our nation’s history. The Tuolumne River downstream of Hetch Hetchy is unique in that although its flow is regulated a twenty‐mile reach is designated as Wild & Scenic. Water from this system is managed per the Raker Act, which allows the City of San Francisco to exclusively use much of it for municipal water supply and hydropower production.
Topical breakouts included: the Tuolumne River watershed and its position with the state’s water management system with a focus on water transfers; the role and history of Hetch Hetchy in California’s water solutions; the geomorphic character of the river and how it relates to water operations; the ecological character of the river and how it relates to water operations; the relevant water policies that pertain to the river; and how climate change is likely to affect water availability and operations.