## 4 Results Analysis
### Summary of Decision Factors
\begin{table}
\begin{tabular}{c c c c c c} \hline  & & **Higher Than the** & **Higher Than the** & & & \\
**City Name** & **Below the 5-Year** & **Period and** & **20-Year Return** & **Higher Than the** & & \\
**Return Period** & **Below the 20-Year Return** & **100-Year Return** & **Period** & **Total** & \\  & & **Period** & **Period** & & \\ \hline Kunming & 307 (28.64\%) & 307 (28.64\%) & 160 (14.93\%) & 298 (27.80\%) & 1072 \\ \hline Qujing & 26 (2.89\%) & 237 (26.33\%) & 419 (46.56\%) & 218 (24.22\%) & 900 \\ \hline Yuxi & 92 (13.43\%) & 392 (57.23\%) & 201 (29.34\%) & 0 (0\%) & 685 \\ \hline Baoshan & 12 (2.15\%) & 115 (20.57\%) & 243 (43.47\%) & 189 (33.81\%) & 559 \\ \hline Zhaotong & 202 (16.22\%) & 496 (39.84\%) & 489 (39.28\%) & 58 (4.66\%) & 1245 \\ \hline Lijiang & 56 (9.84\%) & 190 (33.39\%) & 204 (35.85\%) & 119 (20.91\%) & 569 \\ \hline Puer & 132 (19.50\%) & 193 (28.51\%) & 331 (48.89\%) & 21 (3.10\%) & 677 \\ \hline Lingcang & 17 (4.08\%) & 97 (23.26\%) & 280 (67.15\%) & 23 (5.52\%) & 417 \\ \hline Chuxiong & 105 (12.17\%) & 262 (30.36\%) & 335 (38.82\%) & 161 (18.66\%) & 863 \\ \hline Honghe & 40 (3.93\%) & 343 (33.69\%) & 524 (51.47\%) & 111 (10.90\%) & 1018 \\ \hline Wenshan & 89 (10.19\%) & 183 (20.96\%) & 343 (39.29\%) & 258 (29.55\%) & 873 \\ \hline Xishuangbanna & 93 (30.59\%) & 108 (35.53\%) & 83 (27.30\%) & 20 (6.58\%) & 304 \\ \hline Dali & 59 (4.21\%) & 480 (34.21\%) & 634 (45.19\%) & 230 (16.39\%) & 1403 \\ \hline Dehong & 154 (42.08\%) & 132 (36.07\%) & 43 (11.75\%) & 37 (10.11\%) & 366 \\ \hline Nujiang & 2 (0.73\%) & 163 (59.71\%) & 43 (15.75\%) & 65 (23.81\%) & 273 \\ \hline Diqing & 77 (23.77\%) & 118 (36.42\%) & 129 (39.81\%) & 0 (0\%) & 324 \\ \hline Total & 1463 (12.67\%) & 3816 (33.04\%) & 4461 (38.63\%) & 1808 (15.66\%) & 11,548 \\ \hline \end{tabular}
\end{table} 
Table 3: Flood control capacity of villages along rivers in Yunnan. Subsequently, we used ArcGIS 10.2 software to spatially correlate 11,548 villages along the river with 2193 small watersheds to determine the actual flood control capacity of each watershed and the population in areas made hazardous by flash floods. The results revealed that all the villages were distributed in 1639 small watersheds, and the remaining 554 small watersheds without village distribution were uniformly classified as the general prevention and control zoning of flash flood disaster; the size of this area is 81,209.80 km\({}^{2}\). Among the small watersheds with village distribution, there were 658 that contained villages with a flood control capacity of less than a 5-year return period. There were also 981 small watersheds containing villages with a flood control capacity higher than the 5-year return period but lower than the 100-year return period; of these, 532 small watersheds contained villages with flood control capacity higher than the 5-year return period but lower than the 20-year return period. The remaining 449 small watersheds contained villages with flood control capacity higher than the 20-year return period but lower than the 100-year return period. These small watershed levels of the flash flood prevention division had to be combined in the judgment area population.