Under the watchful eyes of everyone, Gu Fan voiced his thoughts. He first spread out the ancient map, pointing to it, "What we currently know is that there's a lake to the east of Qianye, which is also the oasis we passed earlier. Let's make a presumption. If Qianye is far from water sources, it implies that they must have tapped into groundwater. In other words, there is groundwater beneath Qianye. Furthermore, the oasis exists because of the underground water. Nobody would disagree with this, I presume?"
Everyone concurred. Scratching his head, Lu Yi said, "We can't help it. We are not geology experts. Even if we wanted to object, we can't. Moreover, what you said makes sense."
"Thank you for your support, my dear Lu Yi." Gu Fan paused a brief moment before continuing, "There's groundwater underneath Qianye and the oasis. What if there's an underground river connecting the oasis and Qianye?"