River Basins Biogeochemical Database

Emilio Mayorga, 12/4/2007

  1. Description of current Amazon Rivers database. Somewhat oudated.
  2. Access a crude prototype of a dynamic mapping application showing sampling sites, their drainage areas, rivers, hydrographic gages, etc.
  3. Experimental web-based access to the current Amazon Rivers database. Currently includes only simple queries. To connect from Microsoft Access (or other Windows programs), you'll need the "ODBC Driver"; you can get it here. Unzip the file after downloading. Then double-quick on the only file you'll find (a .msi file) and follow the easy instructions. Works best with Windows 2000 and higher, but will work with Windows NT also. Of course, you'll also need detailed access information from me!
  4. Proposed new database model (data structure). Work in progress. Here are discussions of the need for a new data model, the shortcomings of the current one, and issues still unresolved. An Access file implementing the data model shown in the diagram above can be downloaded here. This is only schematic; not all fields are properly defined.
  5. The database makes extensive use of geographical information about river sampling sites and their drainage areas. These sites were geo-registered relative to a river network dataset based on the DCW and extensively corrected for topological errors. In order to systematically extract drainage areas and establish network relationships between sites, I developed a new algorithm to create a "flow direction" grid from the corrected vector network. The nominal resolution for this flow direction grid and derived raster datasets is 0.005° (500 meters). The entire GIS dataset can be downloaded from the LBA site. To learn more about the algorithm and derived dataset for the Amazon, including their limitations, see this article:
    Mayorga, E., Logsdon, M. G., Ballester, M. V. R. & Richey, J. E. (2005). Estimating cell-to-cell land surface flow paths from digital channel networks, with an application to the Amazon basin. Journal of Hydrology 315: 167-182.