The following table gives the measured rainfall and surface runoff from a 65-acre watershed. Values given are averages over the time interval. Compute the accumulated storage (ft3) of water within the watershed. Plot on the same graph the inflow, outflow, and cumulative storage as a function of time

The following are the ordinates of the 4-hr unit hydrograph for a watershed: Time (hr) 0 2 4 6 Discharge (m/s) 0 20 50 75 i) Derive the 2-hr Unit hydrograph. ii) What is the area of the watershed? 8 90 10 40 12 0

The 60-year record shows that the annual maximum discharges for a river have a mean of 30,000 cfs, a standard deviation of 28,000 cfs, and a skewness coefficient of 3.15. If the annual maximum discharge can be described by the Extreme-value Type I distribution, what is the probability that the annual maximum discharge exceeds 100,000 cfs at least once in next 10 years? (Note: The sample size is 60. Conduct interpolation using exceedance probabilities or cumulative probabilities.)

Problem 12. (7.76 Chin) During a critical 24-month period the average monthly inflows to a reservoir and the average water demand are given in Table 7.10. Use these data to estimate the minimum required storage volume of the reservoir to overcome that critical period. TABLE 7.10 Average inflow Average demand (m³/s) Average inflow Average demand Average Average inflow (m³/s) demand (m³/s) Month* (m³/s) (m³/s) (m³/s) Month Month 1000 1100 1200 1300 1350 1270 1120 1230 1320 1250 1240 1550 1600 850 1300 17 1400 1400 1400 1130 10 1200 18 11 12 13 19 20 21 1310 1370 1100 1000 1170 1210 1000 1400 1400 940 1000 1300 1260 1400 14 820 1100 22 1200 1400 1400 880 1040 1200 1300 15 23 1100 930 16 1290 24 1080 1000