Abstract A methodology based on general hydraulic relations for rivers has been developed to estimate the discharge (flow rate) of rivers using satellite remote sensing observations. The estimates of discharge, flow depth, and flow velocity are derived from remotely observed water surface area, water surface slope, and water surface height, and demonstrated for two reaches of the Yukon River in Alaska, at Eagle (reach length 34.7 km) and near Stevens Village (reach length 38.3 km). The method is based on fundamental equations of hydraulic flow resistance in rivers, including the Manning equation and the Prandtl-von Karman universal velocity distribution equation. The method employs some new hydraulic relations to help define flow resistance and height of the zero flow boundary in the channel. Estimates are made both with and without calibration. The water surface area of the river reach is measured by using a provisional version of the U.S. Geological Survey (USGS) Landsat based product named Dynamic Surface Water Extent (DSWE). The water surface height and slope measurements require a self-consistent datum, and are derived from observations from the Jason-2 satellite altimeter mission. At both reach locations, the Jason-2 radar altimeter non-winter heights consistently tracked the stage recorded at USGS streamgages with a standard deviation of differences (error) during the non-winter periods of less than 7%. Part of the error may be due to differences in the gage and altimeter crossing locations with respect to the range of stage change and the response to changes in discharge at the upstream and downstream locations. For the non-winter periods, the radar derived slope estimates (mean = 0.0003) were constant over the mission lifetime, and in agreement with previously measured USGS water surface slopes and slopes determined from USGS topographic maps. The accuracy of the mean of the uncalibrated daily estimates of discharge varied between reaches, ranging from 13% near Stevens Village (N = 90) to −21% at Eagle (N = 246) based on the absolute error, and 5% to −6% based on the error of the log of the estimates. Calibrating to the mean of USGS daily discharge estimates from the streamflow rating for the same period of record at each streamgage resulted in mean absolute errors ranging from 1% to 2%, and log errors ranging from 1% or less. The error pattern of the estimates shows that without calibration, even though the mean is well simulated, the high and low end values over the range of estimates may have significant bias.

中文翻译：

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河流流量卫星遥感估算：在阿拉斯加育空河中的应用

摘要 已经开发了一种基于河流一般水力关系的方法，以使用卫星遥感观测估算河流的流量（流量）。流量、水深和流速的估计值来自远程观测的水面面积、水面坡度和水面高度，并在阿拉斯加育空河的两个河段进行了论证，在 Eagle（河段长度 34.7 公里）和史蒂文斯村附近（到达长度 38.3 公里）。该方法基于河流中水力流动阻力的基本方程，包括曼宁方程和 Prandtl-von Karman 通用速度分布方程。该方法采用一些新的水力关系来帮助定义通道中零流边界的流动阻力和高度。在校准和未校准的情况下进行估计。河流河段的水表面积是通过使用名为动态地表水范围 (DSWE) 的美国地质调查局 (USGS) Landsat 产品的临时版本来测量的。水面高度和坡度测量需要一个自洽的数据，并且来自 Jason-2 卫星高度计任务的观测。在两个到达位置，Jason-2 雷达高度计非冬季高度始终跟踪 USGS 测流仪记录的水位，非冬季期间的标准差（误差）偏差小于 7%。部分误差可能是由于仪表和高度计交叉位置在阶段变化范围和对上游和下游位置排放变化的响应方面存在差异。对于非冬季时期，雷达得出的斜率估计值（平均值 = 0.0003）在整个任务生命周期内保持不变，并且与之前测量的 USGS 水面斜率和从 USGS 地形图确定的斜率一致。根据绝对误差，未校准的每日排放量估算平均值的准确度因河段而异，从史蒂文斯村附近的 13% (N = 90) 到 Eagle (N = 246) 的 -21%，以及 5% 到 - 6% 基于估计的对数误差。根据每个流量计的同一记录期间的流量等级，校准到 USGS 每日流量估计的平均值，导致平均绝对误差范围为 1% 至 2%，日志误差范围为 1% 或更少。估计的误差模式表明，如果没有校准，即使平均值被很好地模拟，