The economy of Song Dynasty was developed, why did the country seldom build major projects?

Just as the Great Wall was built in the Qin Dynasty and the Grand Canal was opened in the Sui Dynasty, such a big project that consumed the country's manpower, material resources and financial resources naturally did not exist in the Song Dynasty.

Of course, economic development is a prerequisite for major national construction projects, but it is certainly not a decisive condition.

Only in the Northern Song Dynasty, there was a mending project that lasted for several generations-Sanyi Uighur.

This is actually to divert the Yellow River.

The governance of the Yellow River in the Northern Song Dynasty was political, so it was called tinkering.

During the Song Renzong period, Wen Yanbo and others suggested that the Yellow River often changed its course and moved northward. If we reach the territory of Liao, the Yellow River will not be a barrier to the Khitan, and it will be a threat to Dasong.

This view is alarmist or sensational.

But Song Renzong thought it was reasonable, so he began to divert the Yellow River from Liuta River to the east and let it flow to the south of Dasong.

"It is impossible to enter the Liuta River. It's decided at night. It is impossible to drown soldiers and drift grass. "

As a result, the Yellow River burst its banks after flowing into the Tahe River, which caused great disaster.

It turns out that many rich places in Hebei have been flooded.

During the Song Shenzong period, Wang Anshi advocated returning to the river, and the Northern Song Dynasty intervened in the Yellow River diversion again. This time, the Yellow River directly came to seize the Huaihe River and entered the sea, which had a greater impact and left a yellow floodplain.

In the Song Zhezong period, the imperial court hoped that the Yellow River would return to the ancient road and make great efforts to transform it.

As a result, the Yellow River burst again and there was a big flood, causing numerous casualties.

Sanyihui River in the Northern Song Dynasty failed to meet the technical requirements for harnessing the Yellow River. The Yellow River is diverted mainly because the riverbed is high, and you can't divert it if you want.

Artificial water diversion in the Northern Song Dynasty is an example of failure in the history of river management.

More importantly, after such a fuss, Hebei, Shandong and northern Jiangsu, which were originally rich, suddenly became depressed.

In particular, the military deployment in Hebei was hit, and many military towns were washed away and abandoned. Later, 8 jin j south, also be picked up a bargain.