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Special Issue on the Role of Systems Analysis in Watershed Management

Watersheds are coupled human-natural systems (CHNSs) characterized by interactions between human activities and natural processes crossing a broad range of spatial and temporal scales. As stressed by a National Research Council (NRC) report (1999), watershed management poses an enormous challenge in the coming decades. The USDA and the EPA adopted a watershed approach to manage watersheds considering the interdependence among human, abiotic, and biotic components and the feedbacks that arise among management practices and their socioeconomic and environmental consequences. Concurrently, the attention of the environmental and water resources systems research community has evolved from the management of individual reservoirs, storm water, and aquifer systems to more integrated watershed or river basin systems. The application of systems analysis tools including simulation, optimization, and their integration offers an analytical mindset and a diversity of tools capable of addressing the complex challenges, which arise from human-natural interactions as well as communicating subsequent analyses to decision makers. Methods of systems analysis have been integral to water resources systems planning and management since the 1960s. Initially, methods of simulation, mathematical programming, and decision analysis borrowed from the field of operations research were applied to water management challenges. Later, in the 1990s, innovations in complex systems arising, in part, from previous contributions from catastrophe theory in the 1970s and chaos theory in the 1980s began to be applied to the field of water resources planning and management. Today, the application of all of these methods that are termed a systems approach remains critical to our field. Perhaps now more than ever before, systems methods are needed to solve watershed management problems due to the emergence of numerous new concerns relating to stakeholder participation, environmental ethics, life-cycle analysis, sustainability, industrial ecology, and design for ecological (as opposed to engineering) resilience (Dobson and Beck 1999). Both practitioners and researchers routinely face watershed management challenges, including, for example, restoring degraded ecosystems to achieve a balance between human and nature, resolving conflicts over protection of open space and environmental quality and development interests, and more generally accommodating within a watershed context water requirements for food, energy, and environment. Addressing these and other challenges requires the development of innovative systems concepts, methods, and algorithms for effective watershed management that can lead to both socioeconomic and environmental sustainability. Recent scientific, technological, and institutional developments have already and will continue to facilitate integrated watershed systems analysis approaches. We expect innovations relating to a wide range of emerging areas to continue facilitating development of watershed systems analysis including, but not limited to (1) distributed watershed hydrologic modeling and digital watersheds facilitated by hydro-informatics with improved forecast capacity; (2) increasing availability of distributed and digital datasets [e.g., remote sensing, sensor-based monitoring, and cyberinfrastructure (CI)]; (3) multidisciplinary research efforts among hydrologists, ecologists, economists, systems experts, and others; (4) institutional and financial support for watershed restoration practices; (5) improvements in computational and optimization algorithms; and (6) evolution in our ability to integrate ecological, environmental, and social objectives into what was once only a more narrow economic analysis (Lund and Cai 2006). Perhaps the most important developments of all relating to the application of water resources systems methods involve advances in computational sciences that have made possible more advanced quantitative analyses and have moved research more broadly into modeling of a watershed or a river basin as an integrated system of, e.g., reservoirs, aquifers, wetlands, and drainage systems. The goal of this special issue is to publish a representative set of papers focused on the field of watershed management modeling [see Zoltay et al. (2010)], which embraces and extends the myriad of recent advances described previously. This special issue is expected to serve the water resources management and planning community by highlighting the current state of some innovative research findings relating to applications of systems methods for solving various watershed management modeling problems. These problems include nonpoint source pollution management in urban or rural watersheds (papers by Jacobi et al., McGarity, Woodbury and Shoemaker, and Limbrunner et al.), water supply (paper by Giacomoni et al.), water allocation (papers by Riegels et al. and Pulido-Velazquez et al.), flood control (paper by Karamouz and Nazif), best management practices (BMPs) design and placement (papers by McGarity, Limbrunner et al., and Karamouz and Nazif), climate change adaptations (papers by Woodbury and Shoemaker and Karamouz and Nazif), total maximum daily load (TMDL) policy assessment (papers by Mirchi and Watkins and McGarity), and watershed system operations (papers by Anghileri et al. and Muste et al.). These problems are addressed through a number of real-world case studies, including both U.S. and international applications. Interestingly, a number of specific suggestions for policy and engineering design and system operations that arise from these case study problems are provided. This set of papers also demonstrates the application of the state-of-the-art systems techniques to analyzing watershed management modeling problems. Classic linear, nonlinear, and dynamic programming models are still useful and exhibit potential for