Guam Hazard Mitigation Plan - Western States Seismic Policy Council

SECTIONFIVERisk AssessmentAs shown in Tables F-25 and F-26 (Appendix F [Vulnerability and Potential Loss Results byVillage]), in terms of village-level population exposed to tsunami hazard, Agat and Santa Ritahave the largest two vulnerable populations with 1,746 (26.5 percent of the village population)and 1,405 (16.1 percent of the village population) exposed people, respectively. Tamuningfollows with 1,198 exposed people (5.7 percent of the village population).Exposure of the Essential Facilities is concentrated in Hagatna, Tamuning, and Piti. Thirty-threeEssential Facilities (worth $22.5 million) are located in Hagatna, 19 in Tamuning (worth $82.2million), and 13 in Piti (worth $9.5 million). In terms of Major Utilities, 11 are located in Piti(worth $245.8 million) and 11 in Merizo (worth $6.8 million). In addition, Piti has 11Transportation Systems in this hazard area that are worth $75.3 million.The largest number of GBS (568 structures worth $197.5 million) exposed to tsunami inundationare located in Hagatna.Wildland FireAs noted previously, for the 2008 Guam HMP, a vegetation-based fuel model was used todetermine wildland fire hazard areas. This model replaces the wildfire model (fuel type, slope,and ladder) used in the 2005 Guam HMP, as the fuel type and critical weather frequency weredetermined to be the most important factors in influencing the location and severity of a wildlandfire.Similar to the 2008 results, a relatively large portion of Guam’s population, about 104,000 people(57.5 percent), is exposed to a very high or high wildland fire hazard, as shown in Tables 5-20and 5-21. The EFMUTS exposed include 145 Essential Facilities (worth $360.7 million), 239Major Utilities (worth $460.7 million), and 73 Transportation Systems (worth $12.1 million). Thesmallest proportion of exposure is of the GBS, but these structures have the highest combinedvalue, with 21,609 structures exposed, worth $2.87 billion.In terms of village-level population exposure, as shown in Tables F-27 to F-30 (Appendix F[Vulnerability and Potential Loss Results by Village]), Dededo has the largest number of exposedpopulation with 10,627 people residing in a very high wildland fire hazard area (and an additional20,903 people residing in a high wildland fire hazard area). Yigo has the second highest numberof exposed population with 6,122 residing in the very high hazard area and an additional 9,498people residing in a high wildland fire hazard area. Though their overall village populations arelow, Merizo and Umatac have the two highest proportions of exposure for their villagepopulations, with 95.7 percent of the village population of Merizo and 95.1 percent of the villagepopulation of Umatac exposed to high and very high wildland fire hazards.Exposure of the EFMUTS is concentrated in Tamuning with 29 Essential Facilities (worth $202.4million) located in a very high or high wildland fire hazard area. Dededo has the most MajorUtilities located in the very high wildland fire area (31 facilities worth $30.3 million) as well asthe high wildland fire area (43 facilities worth $58.3 million). Transportation Systems located invery high or high wildland fire area are located in every village; the village with the highestnumber is Tamuning, with 9 Transportation Systems worth $1.8 million.Exposure of the GBS to high and very high wildland fire hazards is concentrated in Dededo with6,089 structures (61.6 percent of the village GBS), worth $971.1 million.5-70