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<br />An approach to <br />suggested by <br />investigations. <br /> <br />hazard identification and estimation. as <br />the results of the field and model <br />is summarized below. <br /> <br /> <br />q. Since multiple flood channels. each with <br />substantial flow. have been observed in both <br />the models and field studies. the effect of <br />flow splitting lin addition to avulsionsl <br />should be considered. <br /> <br />5. The results of the hazard prediction <br />methodology should be representative of actual <br />depths and velocities at a structure during the <br />base 1100 year) flood event. This is because <br />protective measures should be built to <br />withstand the base flood. as is the case for <br />riverine flood plains. <br /> <br />1. Data on historical floods should be gathered. <br /> <br /> <br />including depth. discharge. and velocity <br /> <br /> <br />measurements, damage surveys. and personal <br /> <br /> <br />accounts. Aerial photographs covering the fan <br /> <br /> <br />over several years time would be helpful in <br /> <br /> <br />establishing the history of fan formation and <br /> <br /> <br />flood migration. <br /> <br />2. field visits. aerial photography. and <br />topographic mapping should be used to identify <br />watershed and fan characteristics. including <br />hydrology. morphology. vegetation. forest fire <br />frequency. and nature of fan development. <br /> <br />3. Qualitative estimates of flood hazard tYPe$ and <br />severity should be made using available data <br />and the relationships between characteristics <br />and hazards presented in figure Q.3. <br /> <br />55 <br />