China is the world's largest aquaculture food producer, contributing approximately 61.5% of global production. Coastal aquaculture ponds have rapidly expanded in China due to extensive land conversion in recent decades, with a net increase of approximately 10,463 km2 and a rate of 327 km2 per year from 1984 to 2016. Although previous studies have provided valued datasets of coastal aquaculture ponds in China at various scales, those data are outdated and limited to coastal ecosystem planning and management particularly due to their moderate spatial resolution (30-m) and temporal resolution (5 or 10 years). China still lacks high-resolution datasets on the spatial distribution of coastal aquaculture ponds at the national scale. Especially in the context of coastal ecological protection, the evaluation of the spatiotemporal changes in coastal aquaculture ponds since 2015 is still lacking. A group led by Prof. WANG Zongming of Northeast Institute of Geography and Agroecology (IGA) of the Chinese Academy of Sciences developed an object-oriented method combining superpixels image segmentation and hierarchical decision trees, resulting in the first annual 10-m spatial resolution national coastal aquaculture pond dataset of China between 2016 and 2021 (China_CAP), with an overall classification accuracy of more than 90%. The resultant dataset reveals that the total area of China's coastal aquaculture ponds experienced a substantial loss of 13.21% from 9,769 km2 in 2016 to 8,629 km2 in 2021. The most remarkable areal reduction occurred in Zhejiang Province, with a decrease rate of 38.24%, followed by Guangdong (27.93%), and these reductions were mostly related to the policy of retuning aquaculture ponds to natural wetlands. Coastal aquaculture ponds in Fujian and Tianjin provinces experienced slight areal gains (7.24% and 2.13%). The generated dataset is vital for formulating and implementing sustainable strategies related to the wise use of coastal wetlands, and it is of great scientific and practical importance to support the evaluation of Sustainable Development Goals. This research was funded by International Wetlands Research League of Alliance of International Science Organizations (ANSO). Contact MAO Dehua Northeast Institute of Geography and Agroecology E-mail: maodehua@iga.ac.cn |
