Surface Water Transitions 1984-2022: A Global Dataset at Annual Resolution

This dataset provides a comprehensive global analysis of surface water dynamics, mapping areas where water has advanced or receded and capturing the timing of these transitions at annual resolution. Using Landsat time series data from 1984 to 2022, this dataset tracks long-term changes in rivers, lakes, reservoirs, and other water bodies, offering critical insights into hydrological shifts driven by natural and anthropogenic factors.

The dataset is structured to include:

Water Transition Data – Raster files indicating areas of water advance and recession, along with the year in which these changes occurred.
Statistical Summary (GeoJSON) – A spatial file containing aggregated statistics, including the magnitude and direction of water transitions for specific regions or water bodies.
Code (TXT) – The Google Earth Engine (GEE) Javascript used to process Landsat imagery and generate the dataset.

This dataset is intended for use by researchers, policymakers, water resource managers, and conservationists seeking to understand water dynamics on a global scale. It can support studies on river meandering, wetland monitoring, floodplain dynamics, and the impacts of climate change on surface water distribution.

The Water Transition image consists of two bands: Band 1 (b1) represents water advance, while Band 2 (b2) represents water recession.

本数据集提供了一项全面的全球地表水动态分析，绘制了水体扩张与退缩的区域，并以年分辨率捕捉了此类变化发生的时间节点。本数据集依托1984年至2022年的陆地卫星（Landsat）时序影像数据，追踪了河流、湖泊、水库及其他水体的长期变化，为解析自然与人为因素驱动的水文变迁提供了关键视角。

本数据集包含以下内容：
- 水体变化数据（Water Transition Data）：以栅格文件形式呈现，标注了水体扩张与退缩的区域，以及此类变化发生的年份。
- 统计摘要（Statistical Summary，格式为GeoJSON）：一类空间文件，包含特定区域或水体的水体变化幅度与方向等聚合统计信息。
- 处理代码（Code，TXT格式）：用于处理陆地卫星（Landsat）影像并生成本数据集的谷歌地球引擎（Google Earth Engine，简称GEE）JavaScript代码。

本数据集面向致力于全球尺度地表水动态研究的科研人员、政策制定者、水资源管理者与生态保护工作者，可支持河流曲流演化、湿地监测、洪泛区动态以及气候变化对地表水分布影响等相关研究。

该水体变化影像包含两个波段：波段1（b1）代表水体扩张，波段2（b2）代表水体退缩。