HR: 09:15h
AN: NB21F-04    [Abstracts]
TI: Dry Weather Runoff Patterns in Arid Watersheds
AU: * Ackerman, D
EM: drewa@sccwrp.org
AF: Southern California Coastal Water Research Project, 7171 Fenwick Lane, Westminster, ca 92683 United States
AU: Stein, E
EM: erics@sccwrp.org
AF: Southern California Coastal Water Research Project, 7171 Fenwick Lane, Westminster, ca 92683 United States
AB: Dry weather flow in arid, urban watersheds is often dominated by non-point source runoff that may emanate from hundreds of individual inputs. These non-storm flows are typically assumed to be relatively constant and modeling and monitoring efforts are designed based on this steady-state assumption. This study investigated temporal patterns in dry weather urban runoff at multiple spatial scales. Flow was monitored at 5-minute intervals at four southern California catchments of various sizes over a 5-month period between December 2003 and May 2004. Non-storm flow was analyzed for spatial and temporal patterns. Mean flow was linearly related to catchment size and the area-normalized flow was consistently between 176 and 185 m³ d^-1 km^-2. Flow in all continuously flowing catchments exhibited varying degrees of 24-hour periodicity. This study showed that non-storm flow in urban watersheds should be based on daily averages because of observed periodicities. Finally, the similarity in area-normalized flow suggested that there might be consistent scaling relationships for dry weather urban runoff based on watershed characteristics.
DE: 1803 Anthropogenic effects
DE: 1836 Hydrologic budget (1655)
DE: 1860 Runoff and streamflow
SC: North American Benthological Society [NB]
MN: 2005 Joint Assembly