降雨 and 降水: rainfall records and precipitation displays
Compare daily 降雨量 records with a 降水 distribution chart and a color-coded model. Read rainfall and precipitation as data terms, keeping classroom representation distinct from field measurement.
Rainfall's result and ongoing records
降雨（こうう） means rainfall. 「長時間の降雨で地面が柔らかくなった。」（Prolonged rainfall softened the ground.） 長時間の describes the prolonged rain, and 地面が柔らかくなった describes the ground's change. The sentence does not give a numerical rainfall amount.
「降雨量を毎朝同じ時刻に記録している。」（We record the rainfall at the same time every morning.） 降雨量 names the quantity recorded, and 記録している describes ongoing recording. 毎朝同じ時刻に supplies the recurring condition of the same time every morning.
A class chart and a model
降水（こうすい） means precipitation. 「地理の授業で降水の分布を示す図を作った。」（In geography class, I created a chart showing the distribution of precipitation.） The completed action is creating a chart of precipitation distribution. 地理の授業で locates it in a geography class; the term is not automatically limited to daily rainfall records.
「模型では山の両側で降水量が異なる様子を色分けした。」（The model uses colors to show the differing amounts of precipitation on either side of the mountain.） 模型では locates the displayed differences on either side of the mountain within a model. The quoted English describes the model's use of colors; it does not report field measurement on an actual mountain.
Names for data and the scope of representation
降雨量 names rainfall amounts, while 降水の分布 names precipitation distribution. Do not restrict every precipitation record to rain or create the opposite rule that 降水 only refers to phenomena other than rain.
The Japanese 色分けした and Korean translation describe the past act of color-coding. The English uses colors describes how the model represents the differences. Preserve these expressions while separating a classroom or model display from field measurement.
What do 「降雨量を毎朝同じ時刻に記録している。」 and 「地理の授業で降水の分布を示す図を作った。」 concern, and does the colored model establish a field measurement on an actual mountain?
Show the answer and why
The first concerns daily rainfall recording; the second concerns creating a precipitation distribution chart in class. The color-coding is a representation within a model, so these examples do not establish measurement or verification on an actual mountain.