Integrated and Distributed Measurement and Modeling of Hydrology and Water Quality in Watersheds
The most challenging task in management strategies to address water quality is locating the critical areas, those with the highest pollution potential within a watershed. The strategy of diffuse pollution abatement is to select and apply conservation practices to these areas based on type of land use activity, physical condition of the watershed, pollutant type and site-specific conditions. Without such knowledge, the TMDL approach may result in improperly assigned expectations to landowners in the watershed, and millions of dollars may be spent without the intended effect on water quality. With a thorough understanding of the physical and socio-economic processes driving successful targeting and adoption of management practices we can develop tools to quantify the reduction in pollutant loading at the watershed outlet. Properly developed tools
can be used to prepare for future challenges such as increased urbanization and climate change. This work provides an understanding of the hydrologic response to climate change in the Pacific Northwest including variability by region and elevation. The largest runoff events in the Pacific Northwest are often caused by rain-on-snow processes. An increase in temperature can dramatically alter the probability/risk of rain-on-snow events. Knowing the hydrologic sensitivity of a particular region to climate change will lead to pro-active watershed management which anticipates future problems rather than responds to problems after they have already occurred. Outcomes of this work include specific recommendations for the selection and placement of conservation practices in agricultural and forest settings of the Northwest Wheat and Range Region. Continued monitoring of surface water quantity
and quality will provide further evidence of the effectiveness of conservation practices in the Paradise Creek watershed. This evidence will translate in recommendations for similar practices in watersheds of the region. Relationships between turbidity and derived constituents such as total suspended sediment and phosphorus may be compared to those found at other locations. The development of approaches to incorporate climate change into watershed models will provide scenario testing tools that can be used to design future actions to lessen the impacts of changing precipitation and temperature regimes on crop production and water quality in watersheds locally and in general.