9299 - Laserfiche WebLink

Home Browse Search

I I I I I I I I I' I I I I I I I I I I Flow Characteristics during the Study Period The average spring peak flow for the State-line gauge is 27,000 cfs and the median peak flow is 24,400 cfs for the 45-year period of record from 1952 to 1996. During those 45 years the earliest peak flow occurred on May 6, 1985 and latest peak was on June 27, 1983. The median date for the peak flow is June 7. The correlation between the magnitude of the peak and its date showed a weak relationship with a r2 of O. 11. Figure 2 gives the median (50%), high (20%) and low (80%) runoff flow hydrographs based on mean daily flows at the state-line gauge. The median hydro graph indicates that flows were either greater or less than that flow during half the years of the period of record. Years that had peak and summer flows between the 20% and the 80% exceedence hydro graphs were considered to have had moderate flow conditions. Years that have peak or summer flows that were equal or greater than the 20% level were considered high flow years, and years with peaks equal or less than the 80% year are considered low. Colorado River Stateline Gage, 1952-1996 30000 ............ ......h..h..nhn..hn.........'m.h..n...mnmmm.mm..h...."" ,.......m... '...h......m.........mnn..........nmm........mn'....nmn...' ..........n.n.......nm.....' ,.... 20000 00..................................................... ...00....................................... ............................................................................h,..h........... ........m........... 26000 m.............................,......................h...... hh ...0............ .h.............................hh........"....................h....."..,.........mn.m..'...............mnn...... . o 4/1 4/16 4/29 6/13 6/27 6/10 6/24 7/8 7/22 8/6 8/19 9/2 9/16 9130 1-20% -50% -80% I Figure 2. Hydrographs for 20%, 50% and 80% exceedence flows for the state-line gage, Colorado River, from 1952 to 1996. 5