Even if the historic return interval is a lot less than 1000 years, if there are a number of less severe events of a similar nature recorded, the use of such a model is likely to provide useful information to help estimate the future return interval.
12.
The 1894 Fraser River flood had a return period of slightly more than 500 years and the 1948 flood was close to a 200-year event . 1998 report warned that although the 1997 Red River flood had a " return interval ranging from 100 to 500 years, depending on the location ", there was a " statistical probability of a similar flood each year ."
13.
The fire history that characterizes an ecosystem is its " fire regime ", which has 3 elements : ( 1 ) fire type and intensity ( e . g ., crown fires, severe surface fires, and light surface fires ), ( 2 ) size of typical fires of significance, and ( 3 ) frequency or return intervals for specific land units ( Heinselman 1981 ).
