Quantifying the spatial scaling relationship for dominant hydraulic routing parameters in the Amazon Basin
Abstract
The current state of terrestrial water cycle models may be adequate, particularly as spatial resolution is increased, for capturing the role of terrestrial processes in the circulation dynamics of global climate. However, as more specific questions are asked (e.g., what is role of the terrestrial water cycle in global biogeochemical cycling; what are the impacts of climate change on global flooding; how can we improve understanding and prediction of the magnitude, trend, timing, and partitioning of terrestrial water stores and fluxes), a large scale hydrologic framework that provides a realistic representation of fluvial flow and transport processes is needed. The challenge in modeling these fine scale processes is that they require parameterization and are highly scale dependent. In this research, we investigate the effects of spatial scale on horizontal conductivity and channel roughness in the Amazon Basin using a hydrologic model that simulates both water-balance and hydraulic transport for uplands, channels, and floodplains. The model uses an irregular computational grid designed for efficient parallelization. The model is parameterized, driven and assessed using six NASA systems: GRACE, JERS1, LANDSAT7, MODIS Terra, SRTM and TRMM. Model results are compared to point/hillslope measurements of conductivity and measured streamflow data. Results are presented for the Purus Basin, a tributary to the Amazon (>350,000 sq km), over a five year period (2001-2005). Preliminary results indicate that horizontal conductivity (cm/hr) increases approximately 2 to 3 orders of magnitude for a one order of magnitude increase in length scale (10 to 200 km).
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2007
- Bibcode:
- 2007AGUFM.H31A0120B
- Keywords:
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- 1805 Computational hydrology;
- 1820 Floodplain dynamics;
- 1839 Hydrologic scaling;
- 1855 Remote sensing (1640)