对亚马逊泛滥平原水位变化的干涉计雷达测量
1Institute for Computational Earth System Science, University of California, Santa Barbara 93106, USA. alsdorf@icess.ucsb.edu
Nature
|March 21, 2000
概括
新的雷达遥感方法现在可以测量偏远河流盆地的微妙水位变化. 该技术使用干扰度合成光圈雷达 (SAR) 数据来监测洪水动态和河流-洪平面交换.
科学领域:
- 水文学的水文学
- 遥感 遥感 遥感 遥感
- 地质物理学 地质物理学
背景情况:
- 准确的河流和洪水平原水位数据对于了解洪水危险,甲生产,沉积物运输和营养交换至关重要.
- 传统的测量站在偏远的盆地稀疏,限制了水位测量的空间覆盖.
- 雷达遥感中的干涉度相位测量在开放水域上通常是不连贯的,阻碍了水位的确定.
研究的目的:
- 开发和验证一种新的方法,用于测量偏远河流盆地的微妙水位变化,使用干扰度合成孔径雷达 (SAR).
- 评估雷达相位测量在被洪水淹没的植被和洪水平原湖泊上的时间连贯性.
- 通过将其与现有的河流标尺记录进行比较,评估新技术的空间和时间准确性.
主要方法:
- 利用来自航天飞机在亚马逊中部的成像雷达任务中的干扰度SAR数据.
- 利用"双反弹"雷达从被洪水淹没的森林和灌木繁茂的湖泊中的水和植被表面返回,以保持相位连贯性.
- 分析了相位观测,以量化来自主河道的不同距离的支流和湖泊的每日水位变化.
主要成果:
- 在亚马逊洪水平原中,证明了能够测量微妙的水位变化 (在20公里范围内每天7-11厘米,在80公里处每天2-5厘米).
- 观察到洪水平原对河流阶段下降的快速反应,与近邻地区的主通道标尺记录一致.
- 验证了在植被水生环境中保持干扰度相连贯性的有效性.
结论:
- 干涉测量SAR提供了一种有前途的技术,用于在偏远的河流流域中增强水位的空间采样.
- 该方法可以直接观察河流和洪水平原之间的水文交换,这对于洪水动态研究至关重要.
- 未来具有先进SAR能力的卫星任务可以显著提高我们对全球水文过程的理解.
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