伏流水

• Reading: ふくりゅうすい
• Romaji: fukuryuusui
• Kanji breakdown: 伏 (fuku) — lie hidden, submerge; 流 (ryū) — flow; 水 (mizu/sui) — water
• Pronunciation: /ɸɯ.kɯ.ɾjɯː.sɯi/

Meaning

Underground water; subterranean stream. Water that flows beneath the surface of the ground, often feeding springs and wells without appearing as a surface river.

A three-kanji compound used in hydrology, geology, and environmental science. 伏流水 differs from groundwater in the strict sense — it refers specifically to river water that has infiltrated the riverbed and continues flowing through gravel and sediment below the surface before re-emerging downstream. In Japan, many rural communities depend on 伏流水 as their source of clean drinking water and agricultural irrigation.

Examples

1. この湧き水は近くの山に降った雨が数十年かけて伏流水となって湧き出たものだ。 This spring water is rain that fell on the nearby mountains and has taken decades to travel underground before emerging as a subterranean stream.
2. 伏流水が豊富な地域では、地表に川がなくても地下水脈が発達していることが多い。 In areas rich in underground water, well-developed subterranean watercourses are often found even where there is no surface river.
3. 農業用水として伏流水を利用する地域では、水量の変動が作物に直接影響する。 In regions that use underground water for agricultural irrigation, fluctuations in water volume directly affect crops.

Usage Guide

Context: hydrology, agriculture, environmental science

Tone: technical

Origin & History

Sino-Japanese compound. 伏 (fuku) means to lie hidden or submerged, 流 (ryū) means to flow, and 水 (sui/mizu) means water. Together they describe water that flows hidden beneath the surface.

Cultural Context

Era: Meiji–Modern

Generation: Adults

Social background: Academic/Rural