Variations in Ecohydrological Function With Climate and Urbanization

Kevan Moffett, Assistant Professor, School of the Environment

Understanding, predicting and managing the responses of ecosystems, water resources and people to climate change and urbanization are among the greatest challenges of this century. With her New Faculty Seed Grant, Kevan Moffett is addressing this challenge.

Moffett came to WSU Vancouver with 10 years of prior research experience in coastal wetlands, preceded by three years of consulting on urban drinking-water supply management. In general, her ecohydrology research group applies core knowledge in the hydrologic sciences, linked with an understanding of water cycling through plants and ecosystems, to better understand the biophysical functioning, spatial arrangement and temporal development of complex systems—including cities, wetlands, agricultural fields and forested hillslopes.

Drawing on all of this experience, the research funded by her seed grant will begin to quantify how ecosystem water cycling varies among natural, agricultural and urban settings across the Pacific Northwest (from the wet coast, across the Cascades, to drier eastern Oregon and Washington) and thereby will help to make ecohydrological predictions given future climate change and urbanization.

Here specific research questions are:

• How does partitioning of precipitation into plant uptake, soil evaporation, runoff, human use and soil/ground storage vary in space and time in an urban setting and across the climate gradient?
• At the local scale, how does variation in urban forest density and type affect this water balance partitioning and also the temperatures of surface runoff to salmon habitat streams?
• In comparison, how is the water balance partitioned in nearby natural forests, impacted to different degrees by past wildfires?

In a recent special projects course on ecohydrology, Moffett and her students made a preliminary assessment of spatial and temporal water balance variations, including urban, agricultural and natural land covers, within five urban areas in the Pacific Northwest. Two graduate students conducted more in-depth research on urban forests (street trees, etc.) and natural forests in Washington. The seed grant provides one semester of support for each of the graduate students to assist with the research.

The research will provide preliminary data and demonstrate the experience and expertise needed to apply for large external grants on related topics. Moffett intends to submit two follow-up proposals to state or federal agencies, one each focused on the urban forest and natural forest systems. In addition, the study will help establish Moffett’s research group as a hub for ecohydrology studies in the Pacific Northwest.