近30年中国滨海滩涂湿地变化及其驱动力

随着人类活动影响的不断加剧，滨海湿地正面临着退化的威胁。尤其是近三十年来，中国东部沿海地区经济发展迅速，中国滨海湿地在时空格局等方面发生了巨大改变。以Google Earth Pro （GEP） s遥感影像为数据源，基于Google Earth Engine （GEE）平台和随机森林分类方法，解译了1990-2020年中国滨海地区的遥感影像，提取不同年份滩涂湿地面积，分析了过去30年间滨海滩涂湿地空间分布变化，从自然原因和政策变化两个方面探讨了中国滨海滩涂湿地时空格局变化的驱动机制。研究表明，中国滨海滩涂湿地呈现总体减少的趋势，总面积减少了42.98%，其中光滩面积减少了46.30%，盐沼面积增加了4.95%。不同省份滩涂湿地面积变化总体趋势与全国一致，与国家政策紧密联系；但不同年份各省份因发展需求和压力不同，滩涂湿地的变化的进程有一定差异。泥沙沉积和水动力条件的变化是滩涂湿地变化的主要自然因素，方针政策的贯彻执行是滩涂湿地变化的重要人为因素，通过出台严格合理管控政策可以促进中国滨海滩涂湿地可持续发展。

Changes and driving forces of the tidal flat wetlands in coastal China during the past 30 years

The coastal tidal flat wetlands are facing the threat of degradation due to increasing human activities. During the past 30 years, the rapid economic development in the urbanized areas of eastern China led to great changes in the temporal and spatial pattern of coastal wetlands. Employing the high-resolution remote sensing images provided by Google Earth Pro (GEP) and Google Earth engine (GEE) platform, the wetland remote sensing images of China from 1990 to 2020 were interpreted and the spatial distribution map of coastal wetlands in the past 30 years was obtained. Combined with the relevant policies, this paper further studied the temporal and spatial patterns and mechanism of China coastal tidal flat wetlands in the past three decades. The results indicated that the total area of the coastal tidal flat wetlands in China had a decreasing trend in the past three decades, reducing by 42.98%. The area of the bare tidal flat reduced by 46.30%, while that of the vegetation area increased by 4.95%. The overall change in different provinces was in consistent with the national trend, which was affected by the national policy. However, due to different development needs and pressures in each province, the progresses of change varied in their tidal flat wetlands. The sediment deposition and hydrodynamic environment were the main natural factors that drove the changes of China''s tidal flat wetland, while policies and guidelines were important human factors. The introduction of strict and reasonable control policies can promote the sustainable development of coastal tidal flat wetland in China.