UNESCO River Discharge Database Development
The original UNESCO site and discharge data were entered from a
hardcopy series of publications entitled "The Discharge of Selected
Rivers of the World" which were published in book form from 1969
through 1984. The series has served as an important source
of information on approximately 1000 stations. These were checked against
existing digital UNESCO station data (NOAA - National Geophysical Data Center;
WMO - Global Runoff Data Center) to form a comprehensive set
of discharge sites for which
summary discharge data was developed. An example of the discharge data developed
for each site shows a range of information about each site.
Below is an overview of the methodology used to develop and error-check
the data entries:
The basin areas given by UNESCO were compared against basin areas
generated for those sites by a
30 min. simulated network topology (STN-30).
Differences between the two were investigated to check the soundness
of the UNESCO data as well the validity of the STN-30. Several
differences were found that could not attributed to errors in the
STN-30 and were assumed to be an error on the part of UNESCO and have
been noted in the database. An example a graph showing the comparison
between these data soures is shown
- The data were stored in two related tables, one with the discharge
station information, and one table with the discharge data
itself. An example of the tables that were created is
here. These two tables
were linked via a common Geographical Reference Code (GeoRep).
- When the latitude and longitude for a site were not listed, the
Times Atlas of the World was consulted
to derive the
coordinates . If the given discharge station name was not present
in the Times Atlas, or in any local maps that were available to us,
the latitude and logitude were calculated from the UNESCO GeoRep
given. For example, iF03 = -80 longitude, 53 latitude. These
points were imported into Arc/Info (ESRI, Redlands, California) and
displayed over the
ArcWorld (1:3000000) rivers coverage (ESRI), where their coordinates were adjusted
to lie directly upon the approprite river.
- When there was no GeoRep available, as was often the case with
the digital data, the site was discarded.
- When a site had little or no associated descriptive data, the site was discarded.