Utah Landslide susceptibility map reporting landslide susceptibility without historical incidence data California Landslide susceptibility map reporting landslide susceptibility without historical incidence data Rating Scale Determination The Hazard Rating scale for landslides was determined using the following steps: The Landslide Overview Map of the Conterminous United States from USGS was identified as an interact-able map. The seven possible landslide region designations were identified and are defined below No data – no data is reported for this region Sus-mod – region has moderate susceptibility to landslides and a low historical incidence of landslides Sus-high – region has high susceptibility to landslides and a low historical incidence of landslides Combo high – region has high susceptibility to landslides and a moderate historical incidence of landslides Low – region has both a low susceptibility to and historical incidence of landslides Moderate – region has both a moderate susceptibility to and historical incidence of landslides High – region has both a high susceptibility to and historical incidence of landslides The landslide region designations were organized so that those with higher incidences and/or susceptibilities were considered a greater hazard. Hazard Rating Table Table 10. Landslide Hazard Ratings. Rating Category Hazard Rating Hazard Occurrence Descriptor Landslide Region Designation Description Very High 4 Frequent Area has high landslide incidence and susceptibility. (High) High 3 Occasional Area has moderate landslide incidence and susceptibility (Moderate) OR Area has one of the following “combination” landslide incidence and susceptibility (Combo-high): moderate incidence and high susceptibility; high incidence and moderate susceptibility.
The Tool outputs a Hazard Rating using the guidelines above in Table 31. External Chemical HAZMAT Exposure, Maritime Description of Hazard Chemical HAZMAT movement along waterways is a relatively less common mode of HAZMAT transport than either rails or highways, yet it poses a potential hazard. Release of hazardous material into the water system can have serious and far-reaching consequences to both humans and the environment. The past incidence of HAZMAT release during maritime transport is indicative of the future likelihood. The above scale is based on the last 20 years of HAZMAT transportation incidents using water transportation reported to PHMSA. The rating category and Hazard Rating for a specific facility/asset is based on the number of incidents that historically occurred in the city in which the facility/asset is located. The more incidents occurring in the city in which the facility/asset is located, the higher the Hazard Rating. Rating Scale Determination The Hazard Rating scale was determined using the following steps: The PHMSA Incident Reports Database was used to determine that Alaska was the state with the highest number of maritime HAZMAT release incidents. The PHMSA Incident Reports Database Search was used to determine the number of HAZMAT release incidents occurred in the last 20 years in Alaska that were associated with maritime transportation. The smallest (0 incidents) and largest (> 166 incidents in Anchorage) number of maritime HAZMAT releases in Florida cities were identified. These values represent a Hazard Rating of 1 and 4 respectively. The majority of cities in Florida had very few or no historical incidence of highway HAZMAT release; only Anchorage had more than 50. Thus the hazard scale was set to allow for more resolution when considering 50 or fewer incidents. Hazard Rating Table Table 32. Hazard Ratings for HAZMAT Maritime Incidents. Rating Category Hazard Rating Hazard Occurrence Descriptor Hazard Frequency Very High 4 Frequent The city in which the facility/asset is located has had more than 50 HAZMAT maritime incidents in the last 20 years. High 3 Occasional The city in which the facility/asset is located has had 6 to 50 HAZMAT maritime incidents in the last 20 years. Moderate 2 Infrequent The city in which the facility/asset is located has had 1 to 5 HAZMAT maritime incidents in the last 20 years.