If floods have not occurred in the immediate past,

[keannu]

Considering the context, the underlined is not a predicitive conditional, but a factual conditional. And it's either general truth or habitual act, but general truth is usually scientific fact, so is it habitual act? I think whether it's general truth or habitual act, it is a fact, but I need a detailed label to explain to my students.

ex)We may have insurance for natural disasters but whether people buy the insurance or not is greatly affected by recent experiences. Purchase of new earthquake insurance policies, for example, rises sharply right after an earthquake but purchases decline steadily from that point, as distinct memories become less clear. If floods have not occurred in the immediate past, people who live on frequently flooded areas are far less likely to purchase insurance. And people who know someone who has recently experienced a flood are more likely to buy flood insurance for themselves, regardless of the flood risk they actually face.

[5jj]

The writer is describing a situation he presents as generally true. In this particular sentence, 'if' is not very different in sense from 'whenever'.