What does yanggou mean?

Catchment is a drainage ditch exposed from the ground.

The drainage ditch in front of the house is called a sewer. There is not a saying called "capsizing in a sewer", but "sewer" itself also means "the ditch that drains water in an ancient house". Therefore, it makes sense to understand that the boat capsized in front of one's own house. Of course, this sentence is a joke. As for this ditch, it is usually cleaned once at the end of a year, and it is rarely cleaned at ordinary times. Choosing this time is mainly related to its usual function.

This ditch is mainly used for drainage. No matter the nearby water flow or the rain brought by rainy days, it can be diverted away from this ditch without causing savings or even extending into the house. Choose to clean at the end of the year, because it happens to be winter. Apart from being relatively dry in winter, many wild plants have withered at this time, which is much more convenient to clean up, and it will not rain suddenly and get caught off guard.

If it is cleaned in other seasons, it is not easy to choose the time, and it is difficult to ensure that no other animals survive in wet soil. In addition, there may be some rotten things buried in wet soil, which is inconvenient and unsafe to clean.

In fact, apart from the open ditch, there were many stresses in the past, and perhaps many of them were not preserved because they were ignored. The open ditches that have been preserved to this day have been upgraded with the continuous improvement of people's aesthetics, and some will be built with concrete or even tiled.