Amazon Rivers Biogeochemical Database - Description

Emilio Mayorga
Created: 5/22/2000
Update: 6/22/2003

This database has been developed in Microsoft Access, and its goal is to group into a single framework all available biogeochemical data from rivers in the Amazon. In addition, it links these measurements with information about the characteristics of corresponding drainage areas, river network, and network relationships. The main objective of this database is to provide a convenient and flexible tool to analyze the data and extract the desired information; it was not designed to be a definitive archival file.

The overall organization of the main structural tables and relationships among them are shown in a diagram below. The main structural elements/tables are:

  1. Stations: Each individual site that has been sampled at least once.
  2. River Systems: Major basins or reaches that have been the focus of intensive sampling: Amazon (mainstem and mouths of major tributaries), Madeira, Ucayali, Beni, Ji-Parana, Negro, Jau, Pachitea. Note that the Amazon is defined at beginning at the confluence of the Ucayali and Marañón rivers in Peru, where in fact the river is first called Amazonas. Each station is assigned to one or more River System, in the table RivSystemsStations; for example, a station in the Ji-Parana basin will be assigned to both the Ji-Parana and Madeira River Systems; and the mouth of the Ucayali is assigned to both the Ucayali and Amazon River Systems. Each river system is defined to have a "main trunk"; this generally corresponds to the river trunk that has been sampled most intensively, and not necessarily to the actual main headwaters or source.
  3. Transects: A region or set of sites that have been sampled during a single trip or expedition. Each transect can have multiple expeditions, such as the 12 cruises of the Amazon mainstem transect. Transects defined include: Bolivia/Beni, Peru, Amazon mainstem, Ji-Parana, and Marchantaria time series.
  4. Expeditions: Each outing to collect samples for a given Transect, such as each of the mainstem Amazon cruises or each of the Bolivian expeditions.

Basin and river biogeochemical parameters, samples:

  1. Samples: Table recording each observation or sample collection -- the location (station), date, expedition, and additional information.
  2. Biogeochemical parameters. Biogeochemical parameters are grouped into a set of tables, including "Bulk Organic", "InorganicSeds", "StableIsotopes", and others. These measurements are linked to one another and to all the additional information in the database via the SampleID column (key) and the Samples table, which itself is directly linked with the Stations and ExpeditionsTransects tables (see the relationships diagram).
  3. River reach characteristics (discharge, width & depth, hydrograph stage). Linked to the Samples table.
  4. Basin properties. Note that basin properties are "static" -- they do not change with time, as opposed to biogeochemical parameters and river reach/hydrological characteristics. These values are derived from spatial datasets from multiple sources. They include topographic, soils, vegetation, and climatic parameters.

The database uses several integer ID numbers to identify important pieces of information. These are also used to link records in different tables -- for example, to link the Stations and Samples tables via the StationID column. The following IDs or "keys" are used (see the relationships diagram): StationID, SystemID, SampleID, ExpeditionID, and TransectID. Each of these serves as a unique identifier for each unique record or entry.

Database Structure (partial view)


"Structural" tables and their relationships (links). Main structural tables correspond to organizational concepts used in this database.