Watersheds capture not only the rivers and streams navigating through the landscape – they capture the landscape itself. As landscapes change through urbanization, agricultural production, or other natural resource exploitation, watersheds evolve to reflect those changes. Changes in vegetation and/or land use can lead to increased hazards such as landslides and floods, installation of impervious surfaces or tile drainage can lead to higher runoff and altered stream flow regimes, storm and waste water management as well as use of fertilizers and pesticides can alter water quality and subsequently stream ecosystems – a change in any region of a watershed has the potential to affect the entire basin, but this potential is conditioned by the complex spatial structure of the watershed. Climate change now further complicates the issue as expected acceleration of the hydrologic cycle via more intense, shorter duration precipitation events in several parts of the world will alter previous patterns of water availability. Changing water patterns in a watershed will affect vegetation patterns, sediment quantity and distribution in river networks, water quality, and aquatic life in streams and lakes in a way that we cannot accurately predict.
While we expect research focus areas of LIFE to evolve with time, here we identify initial focus topics:
Climate and landscape evolution: Understanding how changing patterns and frequency/magnitude of precipitation and especially of extreme storms will influence landscape-ecosystem evolution and alter patterns and frequency of hazards (floods, landslides, and ecosystem degradation due to accelerated erosion) is a topic of intense interest in the international community. An example of research under this theme uses a newly developed experimental facility of SAFL/NCED (University of Minnesota) in collaboration with the University of Exeter (UK). So far, experimental studies of erosional landscapes and their response to change have been limited due to limitations in data acquisition and difficulties in scaling both rainfall and landscape elements from the field to the laboratory. LIFE will bring together advanced groups in this research area to share facilities and data towards advancing the problem of understanding mountain landscape response to climate change. Preliminary experiments have produced promising results in terms of being able to separate internal variability from externally driven change and in quantifying landscape re-organization due to external forcing.
Hazards: High-impact weather imprints a significant signature on the landscape through floods and landslides with short and long term implications. As extreme events are projected to increase in the future and flood and storm events are among the natural disasters with major effects on human life, understanding climate-landscape interactions for hazard prevention and control is at the forefront of research at the interface of atmospheric sciences, hydrology and eco-geo-morphology. Several LIFE PIs (University of Minnesota, and CIMA) have considerable experience with precipitation modeling using a suite of sensors, including satellite, radar and rain gauge data, and a suite of methodologies ranging from numerical weather prediction models (cloud resolving models to mesoscale parameterizations), as well as experience with modeling extreme orographic precipitation leading to landslides. The group has also extensive experience in landslide prediction using high resolution topography data. LIFE will integrate these groups into a coherent effort to advance modeling of the effects of extreme precipitation events in mountainous complex terrain.
The European Union (EU) Framework 7 projects mandate that research be demonstrated to lead to change in the way natural resources are used and sustained, which parallels NSF’s interest in seeing close two-way coupling between basic science and the use of this science for decision making (actionable science). In that respect, LIFE will bring much needed perspective to the US research arena in using research for management and policy. For example, one of LIFE’s partners, CIMA Research Foundation (Italy), is very much involved in making research available to operational forecasting of hazards, especially floods and landslides. The recent devastating floods in Genoa, Italy have brought the science of hazard prediction to the public eye.
High resolution topography is used to estimate runoff and streamflow, biological productivity in streams, probable landslide location, channel morphology, and bed grain size and use these to model cumulative watershed effects and investigate alternative landscape restoration scenarios. In the last two decades, strong societal demand for river and stream restoration has been stymied by limited understanding of stream disturbance and restoration dynamics. Annual expenditures for restoration projects in the United State exceed $1 billion per year, even though it is widely acknowledged that the science and policy bases for this work are weak, and historically these projects have a poorly measured but clearly mixed record of success (e.g. Kondolf, 2006). NCED has developed unique expertise on science-based stream restoration practice. The Institute de Physique du Globe de Paris (France), the Pontificia Universidad Catolica (Chile), and the University of Aberdeen (U.K.) provide international hubs in experimental and field expertise on river research and sediment transport, eco-hydrology and land use management. LIFE will help integrate and harness this scattered expertise for prediction of environmental fluxes and using these predictions for management and sustainable solutions in a changing world.
Complementary research programs on Watersheds
REACH (REsilience under Accelerated CHange) is a multi-institution, interdisciplinary effort led by the University of Minnesota, with the overall goal to develop a “framework” within which the vulnerabilities of a natural-human system can be assessed to guide decision-making towards sustainability and resilience. A unique element of the framework is identifying and focusing on places, times, and processes of accelerated or amplified change. One specific hypothesis to be tested is that of Human Amplified Natural Change (HANC), which states that areas of the landscape that are most susceptible to human, climatic, and other external changes are those that are undergoing the highest natural rates of change. To test the HANC hypothesis and turn it into a useful paradigm for enabling water sustainability studies, a predictive understanding of the cascade of changes and local amplifications between climatic, human, hydrologic, geomorphologic, and biologic processes are being developed to identify “hot spots” of sensitivity to change and inform mitigation activities.
A schematic of the challenges associated with the Minnesota River Basin (MRB) highlighting the intense crop productivity during the growing season, the artificial drainage that has contributed to an accelerated hydrologic cycle, the geologic legacy of the landscape that predisposes it to increased sediment production and the eventual cascade of these changes to diminishing aquatic species richness in many streams of the basin.
The developed framework is being tested in the Minnesota River Basin (MRB) where pervasive landscape disturbances due to geological history and human actions are affecting changes in ecosystem health and water quantity and quality. Underlying our research efforts are the following science questions (hypotheses): (1) What are the major drivers of change in the MRB, and how do natural and anthropogenic changes interact, propagate and amplify across scales and across processes (physical, biological, and socio-economic)? (2) How can the history and present state of landscape organization inform the identification of “hot spots” of change? (3) What modeling frameworks (from fully distributed to reduced complexity network-based models) can capture the cascade of physical, biological, and socio-economic changes in data-limited environments and for short to long-term predictions? and (4) How can policy and management decisions be informed by understanding the system vulnerabilities and the places/times most sensitive to change? In other words, how can we preserve and improve water quality, ecosystem functioning, and resilience while still meeting the needs of ecosystems and society?
Collaborators: Jacques C. Finlay (Univ. of Minnesota), Karen B. Gran (Univ. of Minnesota – Duluth), Gillian H. Roehrig (Univ. of Minnesota), Patrick Belmont (Utah State Univ.), Peter R. Wilcock (Johns Hopkins University now at Utah State Univ.), Gary Parker (Univ. of Illinois at Urbana-Champaign), Praveen Kumar (Univ. of Illinois at Urbana-Champaign), Catherine L. Kling (Iowa State Univ.), Sergey Rabotyagov (Univ. of Washington).
NSF Water Sustainability and Climate (WSC) project EAR-1209402