Accurate monitoring of the key hydrological processes in paddy fields can reasonably adjust the irrigation of paddy fields to improve water use efficiency and provide more detailed key hydrological information for the assessment of non-point source pollution in paddy fields. However, due to the large spatial heterogeneity of key hydrological parameters such as runoff, ridge height, and infiltration, most hydrological models such as SCS-CN and SWAT-paddy are difficult to accurately simulate, resulting in greater uncertainty in runoff information and non-point source pollution assessment results. To solve this problem, in the present study proposing a new quantitative assessment method for key hydrological processes in paddy fields based on remote sensing and water balance theory. This study aims to : (1) The normal distribution is used to characterize the height of the drainage outlet of the paddy field ridge and the height distribution of the initial surface water based on the field observation data.(2) Inversion of high spatial and temporal resolution evapotranspiration based on multi-source remote sensing satellite and geeSEBAL model.(3) Further construction of the relationship model between leakage and water depth. Combined with the water balance model, the spatial and temporal distribution of paddy runoff, irrigation water, water depth and infiltration was simulated and evaluated based on Arcpy automation. The new method proposed in this study will further improve the simulation accuracy of key hydrological processes and non-point source pollution loss in irrigated paddy fields.
 

Paddy fields; Hydrological processes; Remote sensing; Quantitative evaluation