The invention provides a water return area water bloom prediction method and device, and relates to the technical field of environmental science. The method comprises the following steps: acquiring geographic hydrological data and environment
monitoring data of a target hydrological environment, and constructing a three-dimensional hydrodynamic
water temperature model of a backwater area according to the geographic hydrological data and the environment
monitoring data; constructing a three-dimensional
eutrophication model of the backwater area based on the
water temperature, the
water depth, the horizontal flow velocity and the
wind speed obtained by the three-dimensional hydrodynamic
water temperature model of the backwater area; constructing a BP neural
network model based on the backwater area three-dimensional
eutrophication model, and training the BP neural
network model; and obtaining a water bloom risk prediction result of the water return area of the target hydrological environment by using the neural
network model. According to the method, the backwater area three-dimensional hydrodynamic water temperature model is constructed, data support is provided for
chlorophyll a calculation of the backwater area
eutrophication model, a large number of high-
frequency detection devices do not need to be added, the model
operation time is greatly shortened, and the
model prediction efficiency is improved.