After Twilight Changyan's explanation, I finally understood that Xuancang is indeed a topographical feature with a lot of underground caves.

However, in a cave like Lingmu Valley, where there is a connecting cave leading to the depths, no second place has been found. So my first thought was that bringing water into the ground would be a waste.

However, although it was not possible to divert the stagnant water from all over the country into the ground, it was still feasible around the Imperial City, and Twilight Changyan said that he would consider it for a few more days to see if he could dig the underground drainage of the Imperial City and the fortifications within a hundred miles outside the city into the Lingmu Valley.

As for the large territory outside the city wall fortifications, it is also an unknown area for me, although I have concentrated the Xuancang people to live in the imperial city and its surroundings, but if the flood is really going to erupt, it will still rush to the area of the imperial city, and the most effective control method at present is to make a fuss about the river embankment.

However, although Du Changyan is a national teacher, he does not have the experience of personally going out to strengthen Heti, Xuancang ten years ago this kind of task was handed over to various local officials, and now Xuancang's central officials are not in order, let alone local officials. I think it would be very difficult to find a minister with experience in flood control.

As a last resort, I can only ask Twilight Changyan to bring a few people with a little experience to make a plan and a list of materials, Twilight Changyan is always serious about my orders, and the next day I presented what I wanted, and after the next court, I went directly to Xianyang Palace, thinking that after having dinner with Lei Nian, I would let him see if this flood control measure was feasible.

Because Yanyu was still in the fortifications outside the city and couldn't come back, I could only pick up vegetables for Lei Nian, and I didn't know if this Lei Nian was born arrogant or more and more cunning, I didn't see his problem in the night, and now in Xuancang, he really doesn't give people peace of mind when he eats.

Seeing that he was about to put down his chopsticks again, I asked, "Didn't you eat a lot of food before?" How can you be full at every turn now? Do you have something wrong with your body? ”

"Did I dine with you as usual?" Lei Nian did not answer the rhetorical question.

I thought about it and said, "On the road from the night to Xuancang, don't you nibble on steamed buns every day?" ”

"That's because the carriage was bumpy, and it didn't take long for the food to vomit out."

"......" I was a little speechless, "Sure enough, it's a pampered and arrogant little prince, who can't even sit in a carriage, how did you lead troops to fight before?" ”

Lei Nianbai glanced at me, "You're not looking for me to coax me to eat, right?" ”

"I didn't say that my brother had such a good heart." I denied it and thought for a while, "But you still have to finish this bowl of rice, and now Brother Yan is keeping an eye on it, and when he comes back, if he sees that you have lost weight, he will inevitably have to give you some supplements." If you don't want to trouble him, take good care of yourself, eat and take medicine on time, and be less willful. ”

When it came to the domain of words, Lei Nian seemed to be a little jealous, and after thinking for a while, he picked up the bowl and slowly finished the bowl of rice one by one.

After lunch, I laid out the plan of Twilight Changyan on Lei Nian's table, and Lei Nian sat and looked at it for a long time.

When I saw that he was careful, I added: "Xuancang is different from Diheng, there is a canyon at the junction of Diheng and Xuancang, and the last line of defense for Diheng flood discharge is to introduce water into the canyon, and the water at the bottom of the canyon will then converge into the sea. I also thought about using this canyon, but the side of the canyon near Xuancang is a plateau that stretches for hundreds of miles, and if Xuancang wants to dig the flood channel out of the canyon, it is necessary to dig the waterway very deep, and this project is too huge to be completed in ten years. ”

Lei Nian said: "This method is not feasible, Xuancang can only lead the flood to the lower ground, on the contrary, even if it is dug through, it is in the opposite direction of the water flow. ”

"Yes." I nodded, "But the overall terrain of Xuancang is a slope, high near the side of Diheng, low on the side near Yeyou, and Shangping Mountain at the junction with Yeyou will stop the flood, if the water is fierce, even if Xuancang is submerged, the water will not be able to cross Shangping Mountain and discharge into Yeyou." ”

Lei Nian turned sideways and raised his eyebrows at me: "You want the flood to leak into the night?" ”

"How could it be~" I laughed, "There are so many people in the night, how can I make such a plan regardless of their lives, don't you think I am so dark, okay?" ”

Although having said that, I was still a little panicked, after all, the first plan I thought of for flood control was to blow up Shangping Mountain

Lei Nian snorted coldly, "Hmph, you'd better not think about anything that is bad for Yeyou." ”

I hurriedly laughed, "No, no, you see, what I'm discussing with you now is how to control the flood of Xuancang in Xuancang, so that Yeyou will be much safer~"

After explaining it so hard, Lei Niancai lowered his head and looked at the map again, and said lightly: "It is necessary to widen and dredge the river channel and strengthen the river embankment. ”

"Yes, yes, that's what the national teacher said."

"But even so, if the flood is too violent and overflows the embankment, it will still flood outward."

I quickly nodded again, "That's the truth, you see, the last line of defense of Diheng is to discharge the flood into the canyon, and the last line of defense of Yeyou is to discharge the flood into the sea, only Xuancang, sandwiched by the canyon highlands and Shangping Mountain, and neither side is coastal......"

Lei Nian didn't know if he heard my words, so he interrupted me and said to himself: "But the vast land is sparsely populated, and now the people live in the area of the imperial city, and there are only abandoned villages and towns left in the area around Shangping Mountain. As he spoke, he pointed his finger at the crescent-shaped area of Shangping Mountain.

As if I had been empowered, I leaned up and looked at the place he was pointing and asked, "You mean, divert the floodwaters of the Lu River and the Ling River all the way to the lowest part of the Xuancang Terrain, and then gather there...... You mean there's a reservoir here? ”

Lei Nian raised his eyes and glanced at me, "What, do you have a better way?" ”

I hurriedly waved my hand, "I'm not questioning you, I just think your method is excellent!" There is only one valley in Shangping Mountain that connects Xuancang and Yeyu, and if the valley is filled, it will indeed take the shortest time. I pointed to the direction of the Lu River and the Ling River and said: "These two rivers are bounded by widening the river channel upstream, digging deep downward, and strengthening the embankment, while here downward, according to the topography, a little more diversion can make the overflowing river flow naturally to Shangping Mountain." ”

Speaking of which, Cao Kan suddenly came to report that Haoyuan was coming.

Lei Nian immediately rolled up the drawings on the table and put them in the cabinet, and then quickly went to the bed to lie down.

I poured a cup of tea and sat down next to Lei Nian's couch while helping him cover the quilt while saying, "Cough twice." ”

Lei Nian coughed quickly, and I patted his chest while raising my voice and said, "Hey, why is it that your body is still not good after so long?" It really worries me. If you are not good, I will still ask my brother and ask him to find a few famous doctors in Diheng to treat you. ”

Lei Nian glared at me and whispered, "What nonsense? Ahem...... cough cough cough ......"

Hao Yuan must have heard my words, and when he entered the door, he said, "When I go back, send the best imperial doctor in the palace to treat you!" ”