Rainfall amount prediction device, rainfall amount prediction method, and recording medium

A rainfall amount prediction method, comprising:

• in relation to a first period within a prediction period, performing a rainfall prediction according to a first prediction model capable of prediction at a first accuracy, creating a first prediction pattern, and calculating a first total rainfall amount that is the total rainfall amount in the first period according to the first prediction pattern;
• in relation to the entirety of the prediction period, performing a rainfall prediction according to a second prediction model capable of prediction at a second accuracy lower than the first accuracy, creating a prediction pattern, determining an entire total rainfall amount that is the total rainfall amount in the entirety of the prediction period according to the prediction pattern, determining a second total rainfall amount that is the total rainfall amount in a second period that is a period in the prediction period other than the first period by subtracting the first total rainfall amount from the entire total rainfall amount, and creating, under the limitations of the second total rainfall amount, a plurality of second prediction patterns that are prediction patterns for the second period and that involve different patterns of rainfall;
• and
• creating a plurality of rainfall prediction patterns for the entirety of the prediction period by combining, on a time axis, the first prediction pattern and the plurality of second prediction patterns.

A recording medium for storing a rainfall amount prediction program used to cause a computer to execute:

• a first prediction process to, in relation to a first period within a prediction period, perform a rainfall prediction according to a first prediction model capable of prediction at a first accuracy, create a first prediction pattern, and calculate a first total rainfall amount that is the total rainfall amount in the first period according to the first prediction pattern;
• a second prediction process to, in relation to the entirety of the prediction period, perform a rainfall prediction according to a second prediction model capable of prediction at a second accuracy lower than the first accuracy, create a prediction pattern, determine an entire total rainfall amount that is the total rainfall amount in the entirety of the prediction period according to the prediction pattern, determine a second total rainfall amount that is the total rainfall amount in a second period that is a period in the prediction period other than the first period by subtracting the first total rainfall amount from the entire total rainfall amount, and create, under the limitations of the second total rainfall amount, a plurality of second prediction patterns that are prediction patterns for the second period and that involve different patterns of rainfall;
• and
• a pattern creation process to create a plurality of rainfall prediction patterns for the entirety of the prediction period by combining, on a time axis, the first prediction pattern and the plurality of second prediction patterns.