yóu yú / kào jìn / dà hǎi / dì xià shuǐ / biàn chéng / le / xián shuǐ / bù / shì hé / guàn gài

由于靠近大海，地下水变成了咸水，不适合灌溉。

Because it is near the sea, the groundwater has become salty water and is unsuitable for irrigation.