UNH, GRDC, Global Composite Runoff Data Set (v1.0)

The present data set demonstrates the potential of combining
observed river discharge information with a climate-driven Water
Balance Model in order to develop composite runoff fields which are
consistent with observed discharges. Such combined runoff fields
preserve the accuracy of the discharge measurements as well as the
spatial and temporal distribution of simulated runoff, thereby
providing the "best estimate" of terrestrial runoff over large
domains.

The method applied in the preparation of this data set utilizes a
gridded river network at 30-minute spatial resolution to represent the
riverine flow pathways and to link the continental land mass to oceans
through river channels. Selected gauging stations from the Global
Runoff Data Centre data archive were co-registered to a simulated
topological network (STN-30p) developed at the University of New
Hampshire. Inter-station regions between gauging stations along the
STN-30p network were identified. Inter-station discharge and runoff
were calculated to compare observed runoff with outputs from the water
balance model (WBM) simulation. Correction coefficients based on the
ratio of observed and simulated runoff for inter-station areas were
calculated and applied against simulated runoff to create composite
runoff fields.

The present CD contains not only "UNH-GRDC Composite Runoff Fields
V1.0" but also intermediate data sets, such as station attributes and
long-term monthly regimes of the selected gauging stations. Also
included on the CD are the simulated topological network (STN-30p),
STN-30p derived attributes for the selected stations and gridded
fields of the inter-station regions along STN-30p.

An HTML based data explorer was developed to help users of the
CD-ROM view the data. With a standard web browser and the CD it is
possible to navigate from a global view of the data, down to a
subbasin or station level.

The printed version of the report can be ordered free of charge
from GRDC ([e-mail]) or WMO ([e-mail]).

Note: Due to inaccuracies in the topographical dataset used for the
compilation of the simulated river network, errors may occur in the
graphical display of certain lower-order rivers. Users are invited to
send their comments and notification of errors to the e-mail addresses
shown above.

The full report on the UNH/GRDC is available here -
"http://www.grdc.sr.unh.edu/html/paper/index.html"