Question

7. What is the probability that a 100-year flood would occur in anyone year? rbbhty thet ino yer flood wouid orcuraineven ors For this stream the discharge (called streamflow on the graph in Figure 14.33) in cubic feet per second an be determined from the stage in feet above flood stage by using the following equation: Streamflow 2000* (stage)+4000. h. Imagine that your house is 7 ft above flood stage for this same stream. According to the equation above, what minimum discharge would flood the house? Show the calculations. 8. Recall that discharge is the volume of water flowing past a point in a given amount of time and in this context stream stage means the height of water in a stream gauge, not the stage of stream erosion. 1 Patoka R 3 4 5 678 910 15 20 30 40 50 70 100 Assign the highest flow rank 1. Continue to sort through all of the discharges (or stages) for different years finding the next highest magnitude. Give each magnitude flood a rank down the list, s that the second highest is ranked 2 and third, 3, and so on. The next step is to determine the recurren

Answer 1

7, The recurrence interval of the flood is 100 years. The probability of the flood occurring in any given year is the reciprocal of the recurrence interval. Thus, the probability of the 100 year flood is 1/100 = 0.01

8. The flood stage would have to be 7 ft to flood the house. Thu, discharge would have to be

2000*7 + 4000 = 18000ft³/s.