Simenstad, C.A., Burke, J.L., O’Connor, J.E., Cannon, C., Heatwole, D.W., Ramirez, M.F., Waite, I.R., Counihan, T.D., and Jones, K.L., 2011, Columbia River Estuary Ecosystem Classification—Concept and Application: U.S. Geological Survey Open-File Report 2011-1228, 54 p.

Authors used GIS data from State and Federal agencies to develop fine scale ecosystem classifications for the Columbia River estuary.  Past spatial frameworks have categorized ecosystems according to geomorphology, hydrology and salinity.  However most have failed to address geologic history, regional climate, watershed, ocean, river and human development factors which greatly affect estuary ecosystem function.  Simenstad et al. incorporate these factors in their ecosystem classification which divides the Columbia River basin into a series of ecosystems from coarse/regional scale to fine/local scale as follows: ecosystem province, ecoregion, hydrogeomorphic reach, ecosystem complex, geomorphic catena, primary cover class.  The final classification is a visual tool for analyzing the distribution of ecosystem units at a variety of spatial scales.  Authors recommend this technique for individuals pursuing scientific research, monitoring, restoration and management.