The new snow has stopped, the clouds have not fallen, the Yongding River in western Beijing is still frozen, and the flowing water can be seen surging under the ice, reflecting the changes in the clouds in the sky.

A team of more than 40 people escorted a luxurious carriage along the Yongding River all the way north, most of these people were sturdy, carrying a steel knife with a wild goose at their waists, carrying a bow from Tuomu, and even the horses under the crotch were quite miraculous.

In the carriage, a young man dressed in navy blue background and with gold silk moire on his shoulders opened the curtains and looked at the frozen river with a worried face, not knowing what he was thinking.

"Young Master, you can't go along the river any longer." A fierce man about thirty years old came to the carriage, pointed to the three-way road ahead, and persuaded: "It stands to reason that the rightmost one is the best official road, turning to the direction of Changping in the north, but this road is good but not good, we have to go to Cherry Spring, that is, the direction of the Eighteen Ponds in the west of Beijing, then the best way to go is the middle of the Huailai Horse Station...... But if you have to walk all the way along the Yongding River, you can only take the trail on the left. This road is not an official road, post road, more is some idlers to go to the eighteen ponds to play in the spring before walking, now the heavy snow covers the mountain, it is not easy to walk, especially the carriage, when you and the two little girls may have to get off the car and ride a horse. ”

The eldest young master in the car, dressed in a sassy sass, was none other than Gao Pragmatic.

He was still frowning at the moment, and he didn't answer this man's words, but asked: "Zhang Jin, I heard that in the thirty-fourth year of Jiajing, when my uncle entered the Hanlin Academy as an editor, you guarded him in Beijing?" It's been almost fifteen years now, right? ”

The man named Zhang Jin didn't care about Gao Pragmatic's not polite question, and hugged his fists and said, "Young Master Cousin has a good memory." ”

Gao pragmatic pointed to the Yongding River and asked, "What can you tell me about the Yongding River?" ”

Zhang Jin was slightly stunned, and hesitated: "The villain is stupid, I don't know what the young master wants to know?" ”

"Hydrology, history, and so on, you can talk about it." Gao Shishi sighed and added, "I originally planned to rely on the Yongding River to transport supplies back and forth by water between the capital and the other courtyard, but today it seems that I have taken it for granted...... You have been in the capital for many years, and the Cherry Spring Annexes are my uncle's place for leisurely travel, and you must have accompanied my uncle to and from this road, so I would like to hear your views on the water transportation of the Yongding River. ”

"If the Sanggan River is to be transported by water, spring and autumn may be acceptable, but it is a little difficult in winter and summer." Zhang Jin said, finding that he had reached a fork in the road, he still wanted to persuade Gao Pragmatic not to take the spring road on the left, so he simply beckoned the convoy to stop temporarily.

Gao Shi didn't blame him when he saw it, and still sat in the car and waited for him to reply.

Zhang Jin stopped the convoy, arranged a few words casually, and everyone took out some utensils that were immediately spared, snow sweeping, staking piles, and even began to set up three tents.

Zhang Jin himself began to answer Gao pragmatic questions: "In fact, the name Yongding River is only occasionally used by the government on weekdays, and the people generally call it Sanggan River, Wuding River, Xiaohuang River or Hunhe River. ”

Gao pragmatic smiled: "I know the Sanggan River and the Wuding River, and I can guess the reason for the Little Yellow River, but why is it still called the Hunhe River?" Isn't the Hunhe River in Liaodong? ”

Zhang Jin said: "In fact, the reason for calling the Little Yellow River is the same as that of the Hunhe River, after the Jin and Yuan Dynasty, the Sanggan River - uh, the river water of the Yongding River carries the sand and makes a comeback, and the water disaster gradually increases, especially in spring and summer, the river water is turbid, and the Yellow River has a comparison, and the folk have these two common names. ”

"Water damage?" Gao pragmatic's heart moved.

Gao was a southerner before the crossing, when the flood disaster in the south was relatively more severe than in the north, especially in the turn of the century in those years, flood fighting and rescue year after year, and later he joined the work not long after he became the secretary of the county party committee, because of the relationship between the Three Gorges Dam, the flood disaster has been much better, but he still participated in the flood fighting and rescue for several years in a row.

At that time, the city where he was located, the municipal party committee and the municipal government took the lead, and the main leaders divided the responsibility area, and his county was no exception. He, the first secretary of the county party committee, also followed the secretary to patrol the embankment every day, and during the most severe period of the flood peak, he often did not go down the embankment for two or three days. Not to mention that the old secretary in his fifties almost confessed on the embankment twice, even he fainted directly on the embankment once and was dragged down for rescue, but he didn't dare to delay for a minute after waking up, pushed away the nurse, pulled out the infusion tube and immediately rushed to the embankment - people who have not experienced that kind of natural disaster and danger may find it difficult to imagine the mentality of these people: if you want to say that they are afraid of being dismissed, this mentality will of course have, but more on the one hand, they really dare not have an accident, because the responsibility is too heavy! Once it breaks, it will be the destruction of thousands of families, and it will be destroyed directly in front of your eyes, that kind of huge psychological pressure, as a young cadre who has been instilled with patriotism and love for the people since childhood, he really had a feeling of being so nervous that he couldn't breathe. And at that time, many of the soldiers who were fighting on the front line of the flood fight, many of them were not even under the age of 20, Gao Pragmatic was in that environment at that time, and he really felt that the little work he did was nothing - at least he didn't soak in the water for more than ten hours a day and use his flesh and blood to block the flood!

Gao pragmatic paused for a moment, took a deep breath, and asked solemnly: "The flood damage of the Yongding River is very serious?" To what extent? ”

Zhang Jin seemed to recall for a while, and then suddenly smiled: "Young Master Cousin's performance today and the performance of the old master ten years ago are simply poured out of the same mold, if there is any difference, it is that the old master was already a Hanlin ...... at that time I remember that once the old man took a break and went to Cherry Spring to escape the summer, and on the way he had told the villain about the river defense of the Yongding River, and the villain generally remembered. ”

Gao pragmatic said happily: "Then dare to be kind, you and I will talk about it." ”

So Zhang Jin began to tell Gao Pragmatic about the Yongding River defense mentioned by Zhang Siwei at the beginning.

According to Zhang Siwei's investigation, before the Liao Dynasty, the vegetation in the upper reaches of the Yongding River was well preserved, and the amount of cement and sand in the river was small, although the flow also changed seasonally, but it was generally relatively stable. In Li Daoyuan's pen, the Yongding River is "long and solid", and even has the reputation of "Qingquan River". At that time, there were few records of floods in the historical documents, and the Yongding River could still carry boats and boats, which had the benefit of shipping.

After the Jin Dynasty, with the improvement of the status of Beijing city and the expansion of the scale of construction, the forests in the upper reaches of the Yongding River were cut down in large quantities, and the land on both sides of the middle and lower reaches was reclaimed continuously, resulting in the gradual increase of soil erosion, and the color of the river turned black. Since then, the sediment content of the river has continued to increase, and the flood has increased, and it has been called "Hunhe River", "Little Yellow River" or "Wuding River" in the Yuan and Ming dynasties. After the Yongding River rushes out of Shijingshan in the southwest of Beijing, it enters the plain area with gentle slope drop and loose soil, and the river water "rushes and oscillates, migrates and migrates", which directly threatens the safety of Beijing, and the river section between Shijingshan and Lugou Bridge is particularly critical. With Beijing elevated to become the capital and the surrounding prefectures and counties becoming important places in Gyeonggi, securing the Anlan of the Yongding River became an important part of Gyeonggi's defense.

"Barriers" and "dredging" or "blocking" and "sparse" have always been the two major water control strategies in Chinese history since Dayu that are both opposed to each other and mutually beneficial, and specific to the governance of the Yongding River, has always been biased towards "blocking", that is, building embankments.

The large-scale embankment of the Yongding River began in the Jin Dynasty. During the Dading period, the Lugou River was decided in Xiantongzhai (between Shijingshan and Lugou Bridge today), and "the people were plugged within 300 miles of the edict". In the Yuan Dynasty, the floods of the Yongding River became more and more frequent, and the construction of embankments and bank fixing in the section from Shijingshan to Lugou Bridge also increased. From the period from Shizu to the end of the Yuan Dynasty, records such as "Xiulugou Shangliu Stone Path (Jing) Mountain and River Embankment", "Hunhe River Break, Sending Soldiers and Civilians to Block" and other records are frequently seen in the "History of the Yuan Dynasty". From this period onwards, the city of Beijing has shifted from dependence to defense on the Yongding River.

Since then, the Ming Dynasty has ruled the world, especially after Chengzu moved the capital to Beijing, because the threat of the Yongding River to Beijing and its surrounding areas has not weakened, the Hunhe River "flows down in the former of the West Mountain, flooding and harming the crops, sealing the disease, and the local emergency", and the flooding of the Yongding River has become a great hazard in the capital area and an urgent task for local officials. In view of this, the number of embankment repairs continued to increase, and the length of the embankment extended from the Lugou Bridge to the downstream banks, and the scale and grade were also greatly improved.

In the sixteenth year of Hongwu, "the Junsang Qianhe River, from Gu'an to Gaojiazhuang (now belonging to Bazhou) is 80 miles, the west branch of Bazhou is 20 miles, and the south branch of the river is 35 miles." In July of the first year of orthodoxy, Li Yong, the left waiter of the Ministry of Works, "invited 1,500 craftsmen and 20,000 servants" to build the river embankment at the mouth of the wolf's den below the Lugou Bridge. Once it was completed, it was given the name Gu'an Causeway. Twenty Guardians". In the forty-first year of Jiajing, "the book of life is to repair the bank of the Lugou River", "where the embankment extends 1,200 zhang, the height of one zhang is strange, and the width is doubled, and it is stronger than the past to build Shibo (times)." All this can be reversed, and the safety of Beijing has been further dependent on the constraints of the embankment on the Yongding River.