The rationality and harmfulness of regional water transfer are discussed.

① Expand agricultural irrigation area and increase grain output. (2) provide water and electricity. ③ Promote shipping. ④ Improve the water quality in the water receiving area. ⑤ Improve the natural environment of the water receiving area. ⑥ Some water diversion projects or dams (reservoirs) have become local tourist areas. ⑦ Flood control.

The negative side

(1) flooded the land. (2) a large number of immigrants. (3) The inflow of water in the downstream area decreases, and the water quality of the downstream river becomes worse; Salt water infiltration in estuary area; The strength of the river bank is unbalanced and the coast is eroded; The environmental quality along the downstream coast is declining. ④ Water diversion may cause diseases such as malaria, encephalitis and schistosomiasis, which will affect people's health. ⑤ Excessive or improper use of water may cause salinization of cultivated land in the water receiving area. ⑥ The large reduction of plankton has reduced the catch in the estuary area. ⑦ In some rivers, the "flooding" flood during the flood peak period washed away the saline-alkali on the soil surface, and on the other hand, the sediment brought by the flood added fertilizer to the land.