Using satellite altimetry data to augment flow estimation techniques on the Mekong River
Using satellite altimetry data to augment flow estimation techniques on the Mekong River
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DOI：
10.1002/hyp.7811
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发表时间：
2010-12-30
影响因子：
3.2
通讯作者：
Berry, P. A. M.
中科院分区：
文献类型：
--
作者：
Birkinshaw, S. J.;O'Donnell, G. M.;Berry, P. A. M.
卫星测高通常用于从空间提供海洋或大型内陆水体的水位。通过利用专门为内陆沃茨设计的改道方案，当标准技术失败时，也可以恢复有意义的河流水位。利用沿湄公河沿着的ERS-2和ENVISAT的折回波形，与观测到的水位测量值的比较表明，ENVISAT测高值的均方根误差为0.44-0.65米，ERS-2测高值的均方根误差为0.46-0.76米。然而，对于许多应用，阶段是不够的，因为放电是主要要求。因此，假设上游400公里处（万象）的现场数据可用，进行了调查，以估计下游站点（Nakhon帕诺姆（NP））的排放量。考虑了两种假设但现实的情况。首先，NP是一个退役测量仪的所在地，其次，该地点从未进行过测量。使用这两种情况下，预测的每日流量使用的方法与和没有测高阶段的数据。在第一种情况下，使用线性回归方法，测高数据将Nash-Sutcliffe r（2）值从0.884提高到0.935。第二种情况使用已知的河流横截面，而横向流入是从水文模型中推断出来的：这种情况下，r（2）值从0.823增加到0.893。高度阶段数据的使用，以提高估计流量和进一步的应用进行了讨论。版权所有（C）2010约翰威利父子有限公司
Satellite altimetry is routinely used to provide levels for oceans or large inland water bodies from space. By utilizing retracking schemes specially designed for inland waters, meaningful river stages can also be recovered when standard techniques fail. Utilizing retracked waveforms from ERS-2 and ENVISAT along the Mekong, comparisons against observed stage measurements show that the altimetric measurements have a root mean square error (RMSE) of 0.44-0.65 m for ENVISAT and 0.46-0.76 m for ERS-2. For many applications, however, stage is insufficient because discharge is the primary requirement. Investigations were therefore undertaken to estimate discharges at a downstream site (Nakhon Phanom (NP)) assuming that in situ data are available at a site 400 km upstream (Vientiane). Two hypothetical, but realistic scenarios were considered. Firstly, that NP was the site of a de-commissioned gauge and secondly, that the site has never been gauged. Using both scenarios, predictions were made for the daily discharge using methods with and without altimetric stage data. In the first scenario using a linear regression approach the altimetry data improved the Nash-Sutcliffe r(2) value from 0.884 to 0.935. The second scenario used known river cross-sections while lateral inflows were inferred from a hydrological model: this scenario gave an increase in the r(2) value from 0.823 to 0.893. The use of altimetric stage data is shown to improve estimated discharges and further applications are discussed. Copyright (C) 2010 John Wiley & Sons, Ltd.