Published in EcoEdNet, January 1, 2010.
Copyright © 2010 Ecological Society of America.
This work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 2.5 Generic License.
NOTE: At the time of publication, the author Kristin M. Hardy was not yet affiliated with Cal Poly.
This exercise shows students how to relate remotely sensible properties of coastal waters to variations in river discharge using on‐line data resources. Students can then test hypotheses about the effects of climate changes (drought and wet periods), anthropogenic impacts (urbanized, agricultural, or undeveloped watersheds), or seasonality on river discharges and their consequences, if any, on coastal water quality as determined from remotely sensed properties. River flow has been measured for various periods of time, in some cases from almost the beginning of the 20th century, at many locations throughout the U.S. by the U.S. Geological Survey, with data on flow and, in some cases, other parameters available on‐line. Data sets describing remotely sensible properties of coastal waters are available from SeaWiFS and MODIS‐Aqua satellite platforms, and include several aspects of water color that can be related to water characteristics. Examples of simple hypotheses that can be tested using this approach include the predictions that high river discharges are associated with increases in coastal water absorption coefficients and scattering, and that low discharges are associated with low levels of absorption and scattering. Instructions for accessing data sets are provided along with basic information about the nature of these data. Instructors may find portions of this resource useful as bases for separate exercises, as well as opportunities to address broader issues about hydrology and ecological impacts of anthropogenic and natural variations in hydrologic regimes.