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<br /> Table 7. --SwnmaJLY 06 a.vaila.ble data. 60JL th-tee <br /> 4a.ln6a.ll-4un066 even.t6 d~g 1982 <br /> Runoff Runoff <br />Date Rainfall (inches) Rainfall (inches) <br />(inches) (inches) <br /> Plot 1 Plot 2 Plot 3 Plot 4 Plot 5 <br />June 25 1.58 1/1.42 2:/1.07 1.44 ,!/ 0.54 1/0.42 <br />July 26 1.20 .65 .48 .81 .06 .08 <br />August 10 .74 .50 .45 .85 .16 .16 0.10 <br /> <br />1/P1ot boundaries failed during this event, runoff unreliable (see text). <br />l1Stage record poor, runoff questionable (see text). <br /> <br />Results of tria1-and-error adjustment of model parameters to best-fit <br />observed runoff data for plots 1-4 are shown in figures 19 through 22. <br />Records of precipitation producing these runoff events are shown in figure <br />23. Hydraulic conductivity is the controlling parameter, as in the case <br />of fitting rainfall-simulator data. The pressure term, surface-retention <br />capacity, and surface roughness are of secondary importance. Attempts to <br />fit KSAT for the June 25 event were conditioned on matching the rising limb <br />of observed hydrographs; the plot boundaries failed and runoff volumes were <br />unreliable. Other fittings were conditioned on both the shape and volume <br />of runoff. <br /> <br />Similarity in observed runoff response for each storm event for plots <br />1 and 2 (figs. 19 and 20), and then again for plots 3 and 4 (figs. 21 and <br />22), reflects the differences in rainfall-intensity patterns for each storm, <br />for each location. For example, the observed (and computed) hydro graphs for <br />plots 1 and 2 show two peaks for the event of July 26; those for plots 3 and <br />4 show only one. Results are in harmony with observed rainfall-intensity <br />patterns. Observed data show that rainfall-intensity patterns change signi- <br />ficantly over short distances (gages 3,000 ft apart) for these summer thunder- <br />storms. <br /> <br />Apparent consistency in matching hydro graph shape makes the observed <br />results for plots 1 and 2 for the August 10 event seem out of place (figs. <br />19C and 20C). Observed data from both plots show a rapid early rise in <br />runoff to about 1.5 in/h. It is unlikely that the pressure transducers <br />on both plots 1 and 2 overregistered this early rise; it is more likely <br />that the rain gage failed to catch an early burst of rainfall. In any <br />case, the fitted value of KSAT is conditioned to fit the general shape <br />and volume of runoff, and not the early rise. <br /> <br />34 <br />