Flood drainage method for construction period and operation period of channel type waste slag field

The invention relates to a flood drainage method for the construction period and the operation period of a channel type waste slag field, and belongs to the field of water conservancy and hydropower engineering. Before slag stacking, a drainage blind ditch is built at the bottom of the slag field; in the slag stacking period, a temporary flood drainage channel is reserved on the slag face, close to the hillside, of one side of the slag field, the upstream flood of the slag field is intensively drained to the downstream of the slag field, after the slag face is filled with a certain height, the temporary flood drainage channel is backfilled in the non-flood period, a temporary flood drainage channel of the filled slag face is reserved, it is guaranteed that a new flood drainage channel is formed in the slag stacking body in the next flood period, and the steps are repeated till slag discarding is finished; and after slag stacking is completed, a permanent flood drainage channel is built at the top of the slag