Graphs

Trend lines for three reservoirs are given in Figure 1.

Figure 1. Annual Maximum Inflows and their Rolling 5-Year Mean

Figure 1. Annual Maximum Inflows and their Rolling 5-Year Mean

Figure 2 shows the density (smoothed histogram) for logarithm of annual maximum inflows to visually check for normality.

Figure 2. Distributions of $\log{(\mathit{MaxQ})}$

Figure 2. Distributions of \(\log{(\mathit{MaxQ})}\)

Figure 3 shows a more statistical way to check for normality using quantile-quantile plots. We expect the points to fall on the line if the data conforms with the distribution.

Figure 3. Q-Q Plots for $\log{(\mathit{MaxQ})}$

Figure 3. Q-Q Plots for \(\log{(\mathit{MaxQ})}\)

Table 1 shows the extrapolation of 100-year flood level events. The 2006 flood in Folsom stands out from the rest of the flows so much that it exceeds the 100-year expectation derived from the overall data set.

Table 1. Long Term Flood Results
Reservoir MaxRecord Q100
FOL 127617 122513
ORO 127863 169295
SHA 110890 146554

Data Flow

Figure 4 shows the significant processing steps in this analysis.

Figure 4. Data flow for floods analysis