What do fish ditches and fish slides mean for fish farming in rice fields? What are its characteristics?

Fish ditch: a ditch dug in a rice field where fish are raised to lead to a fish tank. Generally in the shape of a field or well. The trench is about 0.5m deep and 0.4m wide. Every 25 meters, open a vertical ditch; 20 meters apart, open a horizontal ditch. Fish can move in the ditch when the rice field is shallow in the sun or when pesticides are applied; When the temperature is too high, swim into the fish to escape the heat. When fishing, you should bring a soft rod, a thin short line and a small sinker, so you can fish without digging a pond. Catch more small crucian carp and small bream. Fish tank: a small pond dug in a rice field to raise fish. Communicate with Yugou. Fish raised in rice fields are used for fishing in Xia Dong in hot weather. Generally, it is opened at the intersection of fish ditch, with a depth of about 1 m and a diameter of1.2m.: The total area is about 1% of the paddy field area. It is a fishing place for fish farms in rice fields. Fishing in the fishway is very beneficial in summer, autumn and winter. You can also catch 1.5-2.5 kilograms of grass carp and herring in rice fields that cross rivers in the south.