Global mapping of the landside clustering of aquaculture ponds from dense time-series 10 m Sentinel-2 images on Google Earth Engine

Spatial distribution information offers a valuable resource for the growing research on evaluating and managing aquaculture and the mechanism of its interaction with the environment, especially concerning landside clustering aquaculture ponds (LCAP). However, studies aimed at obtaining data on global LCAP distribution remains limited. This study combined edge detection and the morphology implemented on Google Earth Engine (GEE) platform to produce the first global spatial distribution data of LCAP using 4,015,054 tiles of the 10-m Sentinel-2 time-series images collected throughout 2020. The study findings showed a total area of global LCAP of 55,337.03 km2. Asia, led by China, had the highest distribution area of LCAP, accounting for 89.12 % of global LCAP. The main LCAP distribution area was the landside 30-km buffer region of coastline, accounting for 75.57 % of global LCAP. Meanwhile, the greatest proportion of LCAP (69.63 %) was located in China. Accuracy verification revealed that the precision and recall error of the results were 83.91 % and 92.49 % respectively, and F1 score was 0.88. A comparison of China, Vietnam, and India, based on data drawn from most of the existing local studies that used remote sensing methods, showed that these countries' aquaculture area differs by less than 10 %. Despite some variation from FAO statistics or official national statistics, the results of our remote sensingbased method show promise in such aspects as global coverage and temporal coherency when compared with the classical statistical method.