You are here:
A WATERSHED-LEVEL APPROACH TO STUDY THE PUTATIVE RELATIONSHIPS BETWEEN LANDUSE CHANGE AND SURFACE WATER FLOW ALTERATION
Citation:
Rochon*, G, W. Shuster**, AND M Goss*. A WATERSHED-LEVEL APPROACH TO STUDY THE PUTATIVE RELATIONSHIPS BETWEEN LANDUSE CHANGE AND SURFACE WATER FLOW ALTERATION. Presented at IEEE International Geoscience & RemoteSensing Symposium, Toronto, Canada, 6/24-28/2002.
Description:
Inter-generationally prudent management of watershed resources will require attention to the interdependence between shifting landuse distributions and their effects on watershed hydrology. Development and increased proportion of impervious surface area has been found to alte landscape hydrologic balance with both direct and indirect impacts on stream flow. These cascading influences can have secondary effects on stream habitat quality and biota. In order to study the long-term, putative effects of development on hydrology at the watershed-level, we compared archival remotely sensed panchromatic images from 1965 (i.e., CORONA) and color infrared airborne images from 1999, with corresponding US Geological Survey stream discharge data for three watersheds with the Little Miami River basin, in SW Ohio. Images were classified to determine proportional land use types for each time period. Flow duration curves were developed for each time period, and were based on data sets comprised of stream flow data covering at least two hydrologic years. Although land use classifications are still in progress, preliminary results indicate major shifts in proportional landuse over the 34-year study interval; and especially from rural or urbanized landuse regimes. The selected watersheds followed a size gradient; stream flow lateation was not observed in the largest watershed. Yet, changes in stream base flow were evident for the two smaller watersheds. However, we anticipate that this method will be more effective with much smaller (<30 sq. mi) watersheds, which involve monitoring at the level of the subwatershed; and with a thorough analysis of trend in and among both hydrographs and hyetographs.