DOI: 10.5194/hess-19-1943-2015
Scopus记录号: 2-s2.0-84928808896
论文题名: Swath-altimetry measurements of the main stem Amazon River: Measurement errors and hydraulic implications
作者: Wilson M ; D ; , Durand M ; , Jung H ; C ; , Alsdorf D
刊名: Hydrology and Earth System Sciences
ISSN: 10275606
出版年: 2015
卷: 19, 期: 4 起始页码: 1943
结束页码: 1959
语种: 英语
Scopus关键词: Errors
; Hydraulic models
; Hydrographic surveys
; Measurement errors
; Rivers
; Sampling
; Surface topography
; Systematic errors
; Water resources
; Discharge calculation
; Discharge estimate
; Model efficiency
; Ocean topography
; Spatio-temporal samplings
; Terrestrial surface
; Two-dimensional measurement
; Water surface elevations
; Surface waters
; discharge
; hydrological modeling
; mathematical analysis
; measurement method
; numerical model
; satellite altimetry
; satellite imagery
; spatiotemporal analysis
; surface water
; two-dimensional modeling
; Amazon River
英文摘要: The Surface Water and Ocean Topography (SWOT) mission, scheduled for launch in 2020, will provide a step-change improvement in the measurement of terrestrial surface-water storage and dynamics. In particular, it will provide the first, routine two-dimensional measurements of water-surface elevations. In this paper, we aimed to (i) characterise and illustrate in two dimensions the errors which may be found in SWOT swath measurements of terrestrial surface water, (ii) simulate the spatio-temporal sampling scheme of SWOT for the Amazon, and (iii) assess the impact of each of these on estimates of water-surface slope and river discharge which may be obtained from SWOT imagery. We based our analysis on a virtual mission for a ∼260 km reach of the central Amazon (Solimões) River, using a hydraulic model to provide water-surface elevations according to SWOT spatio-temporal sampling to which errors were added based on a two-dimensional height error spectrum derived from the SWOT design requirements. We thereby obtained water-surface elevation measurements for the Amazon main stem as may be observed by SWOT. Using these measurements, we derived estimates of river slope and discharge and compared them to those obtained directly from the hydraulic model. We found that cross-channel and along-reach averaging of SWOT measurements using reach lengths greater than 4 km for the Solimões and 7.5 km for Purus reduced the effect of systematic height errors, enabling discharge to be reproduced accurately from the water height, assuming known bathymetry and friction. Using cross-sectional averaging and 20 km reach lengths, results show Nash-Sutcliffe model efficiency values of 0.99 for the Solimões and 0.88 for the Purus, with 2.6 and 19.1 % average overall error in discharge, respectively. We extend the results to other rivers worldwide and infer that SWOT-derived discharge estimates may be more accurate for rivers with larger channel widths (permitting a greater level of cross-sectional averaging and the use of shorter reach lengths) and higher water-surface slopes (reducing the proportional impact of slope errors on discharge calculation). © Author(s) 2015. CC Attribution 3.0 License. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/78541
Appears in Collections: 气候变化事实与影响
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作者单位: Department of Geography, University of the West Indies, St. Augustine, Trinidad and Tobago; Byrd Polar Research Center and School of Earth Sciences, Ohio State University, 125 South Oval Mall, Columbus, OH, United States; Office of Applied Sciences, NASA Goddard Space Flight Center, 8800 Greenbelt Road, Greenbelt, MD, United States; Science Systems and Applications Inc., 10210 Greenbelt Road, Lanham, MD, United States
Recommended Citation:
Wilson M,D,, Durand M,et al. Swath-altimetry measurements of the main stem Amazon River: Measurement errors and hydraulic implications[J]. Hydrology and Earth System Sciences,2015-01-01,19(4)