<br />A.SCOUR
<br />15
<br />
<br />10
<br />
<br />-5
<br />
<br />-10
<br />
<br />I- -15
<br />w
<br />w
<br />u..
<br />z -20
<br />
<br />z
<br />o
<br />j::
<br /><(
<br />>
<br />W
<br />...J
<br />W
<br />
<br />B. FILL
<br />15
<br />
<br />10
<br />
<br />-5
<br />
<br />-10
<br />
<br />-15
<br />
<br />-20
<br />-10
<br />
<br />
<br />".,.-
<br />/'
<br />/'
<br />/'
<br />~'_.
<br />,/'
<br />
<br />5
<br />
<br />.
<br />.
<br />~..
<br />1\\ .,.../ ",'
<br />. \\ " .......,.'
<br />I \. -,'
<br />.t "'..'
<br />......'---....... " ...."
<br />~. '" ......,' ,
<br />. ,
<br />. ,
<br />. ,
<br />, .'
<br />\
<br />\
<br />, ,../
<br />\ -'-
<br />/'
<br />,,,.,.-'
<br />
<br />..'
<br />
<br />..'
<br />................
<br />
<br />JANUARY 7, 1993-
<br />5,530 cubic feet per second
<br />
<br />JANUARY 13,1993-
<br />1,390 cubic feet per second
<br />
<br />JANUARY 18,1993-
<br />5,170 cubic feet per second
<br />
<br />FEBRUARY 8,1996-
<br />16,900 cubic feetper second
<br />
<br />
<br />.......------------
<br />....-
<br />......... ",""'" ---.---.-
<br />/'
<br />/
<br />/'
<br />/'
<br />,""'-
<br />/
<br />/'
<br />/'
<br />.-oJ'"
<br />, /
<br />\ ./'
<br />. ,-.-...........
<br />\".,.-'
<br />
<br />gaging station, and 390 ft upstream from the
<br />gaging station, Historical changes to the PZF were
<br />compiled and are presented (fig,6).
<br />Cableway cross sectlon.- The cross
<br />section at the cableway scoured during increasing
<br />discharge and filled as discharge decreased (figs. 2
<br />and 3; table 1). During the discharge measurement
<br />of5,530 ft3/s on January 7, 1993, the cross section
<br />generally had a wide and shallow shape (fig, 3).
<br />The peak discharge of 52,500 ft3/s occurred on
<br />January 8, 1993 (fig. 2). Following this peak, data
<br />from the next discharge measurement show that
<br />the right portion of the channel filled about 3 ft,
<br />probably during the recession of the flood peak
<br />(fig. 3). Maximum scour was measured on
<br />
<br />o
<br />
<br />5
<br />
<br />
<br />Reference
<br />elevation
<br />
<br />o
<br />
<br />....,..
<br />.."'.... "
<br />........:;---...........,/
<br />
<br /><II' ..... ......;:....-'"
<br />
<br />, \,..' 'l'/
<br />
<br />",,' " I
<br />" / ....
<br />\ ,-
<br />....
<br />
<br />-- -- ... \
<br />
<br />FEBRUARY 8,1993-
<br />16,900 cubic feet per second
<br />
<br />FEBRUARY 10,1993-
<br />4,470 cubic feet per second
<br />
<br />FEBRUARY 20,1993-
<br />9,940 cubic feet per second
<br />
<br />FEBRUARY 21,1993-
<br />3,160 cubic feet per second
<br />
<br />10
<br />
<br />50
<br />
<br />
<br />170
<br />
<br />70 90
<br />STATION, IN FEET
<br />
<br />110
<br />
<br />130
<br />
<br />150
<br />
<br />Figure 3. Cross section from discharge measurements at cableway, Agua Fria River near Rock Springs,
<br />Arizona, 1993. A, Scour, January 7 through February 8, 1993. B, Fill, February 8-24, 1993.
<br />
<br />February 8 during a discharge of 16,900 ft3/s.
<br />Between January 18 and February 8, the width in-
<br />creased slightly in relation to the reference eleva-
<br />tion, and the hydraulic radius more than doubled.
<br />Most of the increase in cross-sectional area, there-
<br />fore, was accounted for by the increase in depth.
<br />
<br />After February 8, increases in discharge
<br />.caused an increase in channel scour, and decreases
<br />in discharge caused the channel to fill (fig. 3).
<br />Data from the discharge measurement made on
<br />February 10 at 4,470 ft3/s show the cableway cross
<br />section filled with as much as 15 ft of sediment
<br />after February 8. The final 1993 flood peak of
<br />30,400 ft3/s occurred on February 20. A discharge
<br />
<br />Results 9
<br />
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