1. Uncertainty in Base Flood Elevation Kate Marney CE 394 Statistics in Water Resources

2. Introduction HEC Statistical Software Package Bulletin 17B analysis National Academies Study Conclusion: – Sampling error does not vary with topography, drainage area, or landscape type Average

3. Objective Gain insight into the sampling variation of extreme water surface elevations in an arid environment. Colorado River in Marble Canyon ( Source: Britannica Online)

4. Identifying Gaging Stations HydroExcel

5. Identifying Gaging Stations

6. Accessing Data

7. Peak Gage Height Data SiteNameStateCountyLatitudeLongitudeGage Number Record Length (years) Drainage Area (sq. miles) COLORADO RIVER AT LEES FERRY, AZAZCoconino36.86471176-111.58821870938000087111800 LITTLE COLORADO RIVER AT WOODRUFF, AZAZNavajo34.7828064-110.04428109394500828072 PUERCO RIVER NEAR CHAMBERS, AZAZApache35.18224716-109.44705209396100362156 CHEVELON FORK BELOW WILDCAT CANYON, NR WINSLOW,AZNavajo34.6364212-110.71429440939750047271 COLORADO RIVER NEAR GRAND CANYON, AZAZCoconino36.10137177-112.08628080940250086141600 EAGLE CREEK ABOVE PUMPING PLANT, NEAR MORENCI, AAZGreenlee33.06450653-109.44229890944700062622 BONITA CREEK NEAR MORENCI, AZ.AZGraham32.955616-109.5311890944780026302 SAN CARLOS RIVER NEAR PERIDOT, AZ.AZGraham33.29644775-110.451484709468500781026 GILA RIVER BELOW COOLIDGE DAM, AZ.AZPinal33.16950607-110.5312119094695005312886 ARAVAIPA CREEK NEAR MAMMOTH, AZ.AZPinal32.84367752-110.61981960947300055537 GILA RIVER AT KELVIN, AZ.AZPinal33.10284042-110.9765015094740009618011 SANTA CRUZ RIVER NEAR LOCHIEL, AZAZSanta Cruz31.3553791-110.5895233094800005982.2 BLACK RIVER BLW PUMPING PLANT, NR POINT OF PINESAZGraham33.4767189-109.76397710948950054560 VERDE RIVER NEAR PAULDEN, AZAZYavapai34.89501953-112.342948909503700442507 VERDE RIVER NEAR CLARKDALE, AZAZYavapai34.85224152-112.065994309504000423503 DRY BEAVER CREEK NEAR RIMROCK, AZAZYavapai34.72863007-111.77571110950535046142 WEST CLEAR CREEK NEAR CAMP VERDE, AZAZYavapai34.53863525-111.69403840950580042241 VERDE R BLW TANGLE CREEK, ABV HORSESHOE DAM, AZ.AZYavapai34.07309341-111.716255209508500815858 SYCAMORE CREEK NEAR FORT MCDOWELL, AZ.AZMaricopa33.69421005-111.54180150951020047164 AGUA FRIA RIVER NEAR MAYER, AZ.AZYavapai34.31530762-112.06404880951250067585 Average59.5

8. Results

10. 09380000 - Stage (ft) Percent Change Exceedance Return Period (year) Computed Curve Stage in ft Confidence Limits Stage in ft 0.050.95 0.230.86331.97434.88528.014 0.527.74428.47230.91725.458 125.50226.00428.10623.597 223.34523.67725.43921.785 520.59420.76322.10119.435 1018.55318.64619.68217.654 2016.49416.53417.30815.807 5013.513 14.05212.985 8011.43111.41311.93510.881 9010.610.57111.11710.021 9510.1789.97810.559.416 999.1349.0729.6928.496

11. Results

12. Future Work Compute standard error for 100 year event Plot standard error against drainage area for each gaging station

13. Questions? Sources: – Mapping the Zone: Improving Flood Map Accuracy (http://www.nap.edu/catalog.php?record_id=12573) – USGS NWIS Website – Bulletin 17B Salt River in Arizona (Source: greglibby.com)