Near real-time flood wave approximation on large rivers from space: Application to the River Po, Italy
Near real-time flood wave approximation on large rivers from space: Application to the River Po, Italy
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DOI：
10.1029/2008wr007672
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发表时间：
2010-05-18
影响因子：
5.4
通讯作者：
Bates, P. D.
中科院分区：
文献类型：
--
作者：
Schumann, G.;Di Baldassarre, G.;Bates, P. D.
本文研究了低成本的星载数据在大江大河洪水事件期间近似纵向表面轮廓的潜力。2000年2月，航天飞机雷达地形任务(SRTM)以空间连续采样的方式测量了地球表面大部分地区的高度，绝对垂直精度在5.6至9米之间。垂直误差已被证明随着地形的复杂程度而变化，在平坦的地形上，垂直误差不那么重要。这使得可以测量水面坡度，并估计大型盆地(如亚马逊河)中的明渠的相关流量。在这些能力的基础上，本文证明了最近在意大利波河98公里范围内发生的一次洪水事件的近实时高分辨率雷达图像与SRTM地形高度数据相结合，产生了与雷达图像与高精度机载激光测高相结合的水坡非常相似的水坡。此外，结果表明，这种星载洪水波近似可以很好地与水力学模型相比较，因此可以在接近实时地应用于不同震级的事件时，评估根据先前事件校准的后者的性能。这些结果不仅对实时洪水管理和洪水预报非常重要，而且还支持即将到来的地表水和海洋地形任务，该任务将定期向全球提供更高精度的水位和坡度。
This paper investigates the potential of low-cost spaceborne data to approximate longitudinal surface profiles during flood events on large rivers. In February 2000, the Shuttle Radar Topography Mission (SRTM) measured the elevation of most of the Earth's surface with spatially continuous sampling and an absolute vertical accuracy between 5.6 and 9 m. The vertical error has been shown to change with topographic complexity, being less important over flat terrain. This allows water surface slopes to be measured and associated discharge volumes to be estimated for open channels in large basins, such as the Amazon. Building on these capabilities, this paper demonstrates that near real-time coarse resolution radar imagery of a recent flood event on a 98 km reach of the River Po (Italy) combined with SRTM terrain height data leads to a water slope remarkably similar to that derived by combining the radar image with highly accurate airborne laser altimetry. Moreover, it is shown that this spaceborne flood wave approximation compares well to a hydraulic model and thus allows the performance of the latter, calibrated on a previous event, to be assessed when applied to an event of different magnitude in near real time. These results are not only of great importance to real-time flood management and flood forecasting but also support the upcoming Surface Water and Ocean Topography mission that will routinely provide water levels and slopes with higher precision around the globe.