Abstract: A crop irrigation method based on a salt leaching fraction disclosed. The method includes: calculating a salt leaching fraction of crops by combining a salt stress and effect of water quality on an irrigation amount of the crops, controlling an irrigation apparatus to perform irrigation and drainage operations by monitoring water and salt in a soil depth corresponding to crop roots, and removing excess salt from the crop roots, thus reducing the salt stress on crop growth, ensuring a crop yield, and reducing waste of water resources while realizing efficient utilization of existing water resources.

Abstract: A spatial autocorrelation machine learning-based downscaling method of satellite precipitation data includes obtaining the TRMM precipitation data and the land surface parameters; preprocessing the land surface parameters to obtain DEM, day land surface temperature, night surface land temperature, day-and-night land surface temperature difference and NDVI with spatial resolutions of 1 km and 25 km; performing a spatial autocorrelation analysis of the TRMM precipitation data to obtain an estimated spatial autocorrelation value of the precipitation data with a spatial resolution of 25 km; downscaling the spatial resolution of the spatial autocorrelation value of the precipitation data from 25 km to 1 km; establishing a nonlinear regression model; obtaining a precipitation downscaling data with a spatial resolution of 1 km based on the nonlinear regression model. A system and a terminal are also provided.