在1986-2022年期间,沼泽减少的速度远快于黄河源湿地在1986-2022年期间的增加
Mengqi Qiu1, Yanxu Liu1, Fuyou Tian2
1State Key Laboratory of Earth Surface Processes and Resource Ecology, Faculty of Geographical Science, Beijing Normal University, Beijing 100857, China.
The Science of the total environment
|July 6, 2024
概括
黄河源地 (YRS) 的湿地绘制显示,从1986年到2022年期间,沼泽的退化和水域的扩张显著. 牧场,而不是气候变化,推动了沼泽的丧失,影响了数百万人的供水.
科学领域:
- 环境科学 环境科学
- 遥感 遥感 遥感 遥感
- 生态系统动力学 生态系统动力学
背景情况:
- 湿地是关键的生态系统,需要监测可持续管理,特别是在全球变暖的情况下.
- 黄河源 (YRS) 湿地,包括一个大型高原泥炭沼泽,面临着退化,威胁着1.1亿人的供水.
- 由于缺乏长期,密集的时间序列数据,评估YRS湿地演变具有挑战性.
研究的目的:
- 开发一种新的方法,用于从1986年到2022年生成YRS的年度湿地地图.
- 分析湿地范围的趋势,并确定观察到的变化背后的驱动因素.
- 为青海-西藏高原可持续湿地管理提供见解.
主要方法:
- 开发了一个决策树样本迁移方法,利用欧几里德距离和陆地地表水指数.
- 使用Landsat 5/7/8数据集和随机森林分类方法生成年度湿地地图.
- 获得了平均样本迁移率为89.21%,整体准确率为95.49%.
主要成果:
- 1986年至2022年间,沼泽面积减少了12.98% (2031平方公里),而水面积增加了31.24% (710平方公里).
- 沼泽的显著下降 (10.96%) 主要转化为草原 (86%) 和不透气的表面 (10%).
- 显著的水膨胀 (6.69%) 主要来自不透水的表面 (82%) 和沼泽 (12%).
结论:
- 牧场活动是沼泽退化的一个更重要的驱动因素,而不是气候变化在YRS.
- 在YRS中的水膨胀与最近气温上升有关.
- 开发的样本迁移方法对长期湿地绘制有效,支持有针对性的保护工作.
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