1.  TITLE

1.1  Data Set Identification.

     River basin streamflow

     (Monthly ; GRDC)

1.2  Data Base Table Name.

     Not applicable.

1.3  CD-ROM File Name. 


     Note:  capital letters indicate fixed values that appear on the CD-ROM 
     exactly as shown here, lower case indicates characters (values) that 
     change for each path and file.

     The file G_GAUGES.FLR contains the gauge list with gauge number, gauge 
     location etc.  The format used for the data filenames is: G#######.sfx, 
     where ####### is the GRDC gauge ID number as listed in G_GAUGES.FLR.  The 
     filename extension (.sfx), identifies the data set content for the file 
     (see Section 8.2) and is equal to .FLR for this data set.

1.4  Revision Date Of This Document.

     April 5, 1995.

                         2.  INVESTIGATOR(S)

2.1  Investigator(s) Name And Title.

     Soroosh Sorooshian
     Professor and Head
     Dept. of Hydrology and Water Resources
     University of Arizona

2.2  Title Of Investigation.

     Streamflow Data of Major River Basins.

2.3  Contacts (For Data Production Information).

              |      Contact 1      |
2.3.1 Name    | Mr. Dan Braithwaite |
2.3.2 Address | Dept. of Hydrology  |
              | and Water Resources |
              | Harshbarger Bldg.   |
              | Univ. of Arizona    |
      City/St.| Tucson, Arizona     |
      Zip Code| 85721               |
2.3.3 Tel.    | (602) 621-9944      |
2.3.4 Email   |dank@hwr.arizona.edu |

2.4  Requested Form of Acknowledgment.

     Streamflow data of major river basins, Ver. 0, Dept. of Hydrology and 
     Water Resources, University of Arizona, in cooperation with Dr. Wolfgang 
     Grabs of the Global Runoff Data Center, Koblenz, Germany.

                            3.  INTRODUCTION

3.1  Objective/Purpose.

     The purpose of making this data set available is to give climate and 
     hydrologic researchers better access to the historical record of runoff 
     from some of the world's major river systems.

3.2  Summary of Parameters.

     This report includes the monthly average runoff from 129 gauging stations 
     for different periods of record, some of which span much of the last 200 
     years.  However, only 14 gauges fully cover the study period (1987 - 
     1988) of the ISLSCP Initiative 1.  These gauges were selected because of 
     the regional significance (not necessarily volume) of the river in 
     question. Gage location, contributing area and period of record are also 

3.3  Discussion.

     The hydrologic cycle is a critical component of global climate studies 
     but is poorly quantified globally in space and time.  Hydrologists have 
     used river runoff as a natural space/time integrator at the basin scale 
     for years and it is possible to extend this concept to larger scales 
     given the appropriate data set. The monumental task of locating, 
     acquiring, digitizing and editing runoff data from around the world is 
     being managed by the Global Runoff Data Center (GRDC) under the 
     auspices of the World Meteorological Organization (WMO) as part of the 
     World Climate Program.

     The aim of this project is to provide a global data set for the 
     validation of climate simulations by global General Circulation Models 
     (GCM's) [Max Planck-IFM, 1993].
     The GRDC has made a portion of their data base of major world rivers 
     available to this CD-ROM data set. Of the rivers included in this 
     release, the full period of record is given and, where needed, daily 
     flows have been converted to monthly averages. Although these basins 
     represent less than 30% of the land surface area, they contribute 
     approximately 46% of the estimated annual global runoff of 40,670 km3 
     [WRI, 1990].
     While monthly average flow is appropriate for most model applications, 
     the presence of extreme events is not preserved so this data set will 
     be of less use to those interested in historical climate extremes.

                        4.  THEORY OF MEASUREMENTS

Stage-discharge relations (discharge ratings) at gauging stations are usually 
developed experimentally from measurements of stage and discharge.

The discharge ratings for a stream or channel may consist of a simple relation 
between stage and discharge, or for a complex situation, it may be composed of 
several relation curves defining discharge as a function of stage, slope, rate 
of change of stage, or other variables.

The stage-discharge relations developed at one point in time are usually not 
permanent nor do they often represent long-time conditions. Changes in the 
stream channel such as scour and fill or changes in channel roughness, aquatic 
growth, debris, or backwater from ice, all result in changes in the stage-
discharge relation. Hence, frequent discharge measurements are necessary to 
define the shape and/or changes in the discharge rating.

Discharge measurements are usually made by the current-meter method; however, 
it is sometimes necessary to resort to indirect measurements of flood flow 
(USGS Office of Water Data Coordination, 1977) to define the upper portion of 
the stage-discharge relation.

For additional information on stream gauging procedure, see Corbett and others 

                            5.  EQUIPMENT

The equipment and methods used to measure streamflow probably vary 
substantially depending on the country and organization conducting the 
measurements.  The specific details for the gauges in this data set are not 
available at this time. For general information on equipment and methods used 
to measure streamflow, see (USGS Office of Water Data Coordination, 1977).

5.1  Instrument Description.

     5.1.1  Platform (Satellite, Aircraft, Ground, Person...).

            Not available.

     5.1.2  Mission Objectives.

            Not available.

     5.1.3  Key Variables.

            Not available.

     5.1.4  Principles of Operation.

            Not available.

     5.1.5  Instrument Measurement Geometry .

            Not available.

     5.1.6  Manufacturer of Instrument.

            Not available.

5.2  Calibration.

     5.2.1  Specifications.

            Not available.


                     Not available.

     5.2.2  Frequency of Calibration.

            Not available.

     5.2.3  Other Calibration Information.

            Not available.

                          6.  PROCEDURE

6.1  Data Acquisition Methods.
     This data was acquired from Dr. Wolfgang Grabs at the Global Runoff 
     Data Centre in Koblenz, Germany.

6.2  Spatial Characteristics.
     Streamflow measurements were made at significant points in most major 
     river basins around the world. The contributing area above each gauge 
     and the gauge location are given in G_GAUGES.FLR (see section 8 for 

     6.2.1  Spatial Coverage.
            Streamflow measurements at significant points of the major river 
            basins around the world recording the cumulative output of the 
            contributing basin.

     6.2.2  Spatial Resolution.

            The data values represent an areal integration over the 
            contributing catchment.  The size of each catchment is listed in 
            the file G_GAUGES.FLR.

6.3  Temporal Characteristics.

     A water year covers portions of two calendar years, beginning in October 
     of a year and ending in September of the following year. (e.g. wateryear 
     1991 consists of Oct-Dec of 1990 and Jan-Sep of 1991).

     6.3.1  Temporal Coverage.

            The period of record varies for each gauge.
            Over the entire data set:
            earliest wateryear      1807
            latest wateryear        1991
            latest starting year    1986
            earliest ending year    1961
            longest span            178 wateryears
            shortest span           1 wateryear

            Note: Only fourteen gauges fully cover the period 1987 to 1988.

     6.3.2  Temporal Resolution.

            Monthly averages.

                           7.  OBSERVATIONS

7.1  Field Notes.

     Not available.

                         8.  DATA DESCRIPTION

8.1  Table Definition With Comments.

     The file G_GAUGES.FLR is a table that contains the gauge list (for all 
     gauges in this data set) with gauge number, gauge location and additional 
     information (see section 8.2, 8.3 and 8.4).  The G#######.FLR files, each 
     contain a table that has one record for every water year, consisting of 
     the water year and 12 flow rate values (one for each month of a year). 
     Each G#######.FLR file contains all the flow data for a specific gauge.

8.2  Type of Data.

|                 8.2.1                  |               |          |          |
|Parameter/Variable Name                 |               |          |          |
|    |               8.2.2               |     8.2.3     |  8.2.4   |  8.2.5   |
|    |Parameter/Variable Description     |Range          |Units     |Source    |
|WYEAR                                   |               |          |          |
|    |The water year (e.g. wateryear 1991|min = 1807,    |[years]   |          |
|    |consists of Oct-Dec of 1990 and    |max = 1991     |          |          |
|    |Jan-Sep of 1991).                  |               |          |          |
|FLOW                                    |               |          |          |
|    |Streamflow in monthly averages     |min = 0,       |[meters^3]|gauge     |
|    |                                   |max = 246000   |[sec^-1]  |          |
|    |                                   |missing =      |          |          |
|    |                                   |-9999.00       |          |          |
|GAGE_ID_NUMBER                          |               |          |          |
|    |The gauge identification number    |Not            |Not       |          |
|    |                                   |applicable     |applicable|          |
|RIVER_NAME                              |               |          |          |
|    |Name of the river the gauge is     |Not            |Not       |          |
|    |located on.                        |applicable     |applicable|          |
|STATION_NAME                            |               |          |          |
|    |Name of the gauge station.         |Not            |Not       |          |
|    |                                   |applicable     |applicable|          |
|COUNTRY                                 |               |          |          |
|    |Name of the country the gauge is   |Not            |Not       |          |
|    |located in.                        |applicable     |applicable|          |
|LATITUDE                                |               |          |          |
|    |Geographic latitude location of    |min = 0,       |[dec deg] |          |
|    |the gauge.                         |max = 9000     |[100]     |          |
|LONGITUDE                               |               |          |          |
|    |Geographic longitude location of   |min = 0,       |[dec deg] |          |
|    |the gauge.                         |max = 18000    |[100]     |          |
|CATSIZE                                 |               |          |          |
|    |The contributing area upstream from|min = 97,      |[kilo     |          |
|    |the gauge.                         |max = 4640300, |meters^2] |          |
|    |                                   |missing = blank|          |          |
|ELEVATION                               |               |          |          |
|    |The elevation of the gauge.        |min = 0,       |[meters]  |          |
|    |                                   |max = 2000,    |          |          |
|    |                                   |missing = -99  |          |          |
|FIRST_WYEAR                             |               |          |          |
|    |The first water year for the gauge |min = 1807,    |Not       |          |
|    |location.                          |max = 1986     |applicable|          |
|LAST_WYEAR                              |               |          |          |
|    |The last water year for the gauge  |min = 1961,    |Not       |          |
|    |location.                          |max = 1991     |applicable|          |
|NOTE                                    |               |          |          |
|    |Note whether the original data was |Not            |Not       |          |
|    |monthly or daily.                  |applicable     |applicable|          |
The WYEAR and FLOW parameters are located in each G#######.flr file. All other 
parameters, listed above are located in the G_GAUGES.FLR file.

8.3  Sample Data Base Data Record.
     For header file (G_GAUGES.FLR):
     1134100 Niger                                   Koulikoro
         MI 1287N   755W  120000    20 1907 1991 D
     1134300 Bani                                    Douna
         MI 1322N   590W  101600   271 1922 1991 M
     1147010 Zaire                                   Kinshasa
         ZR  430S  1530E 3475000    58 1903 1984 M
     1159100 Oranje                                  Vioolsdrif
         ZA 2876S  1773E  850530   -99 1965 1986 M

     For data files (G#######.FLR):
       1897    258.00    220.00    164.00    218.00    224.00   1220.00
           3710.00   4510.00    657.00    332.00    245.00    195.00
       1898    201.00    223.00    144.00    130.00    191.00    182.00
           2430.00   3520.00   1650.00    441.00    287.00    186.00

8.4  Data Format.

     The length of each record, in the G_GAUGES.FLR file, is 131 characters 
     long and the parameters are space delimited.

     The record format and parameters are:

     column #        parameters
     1-7             GRDC gauge identification number.
     9-48            River name padded with spaces.
     49-89           Station name padded with spaces.
     90-91           Two letter country abbreviation.
                         AG - Argentina         LT - Lithuania         
                         AU - Australia         MI - Mali              
                         BJ - Benin             MW - Malawi            
                         BM - Burma (Aynmar)    MX - Mexico            
                         BW - Bangladesh        MZ - Mozambique        
                         BZ - Brazil            NR - Nigeria           
                         CD - Chad              PK - Pakistan          
                         CG - Congo             PL - Poland            
                         CI - China             RO - Romania           
                         CN - Canada            RS - Russia            
                         CO - Columbia          SG - Senegal           
                         CZ - Czech Republic    SN - Sweden            
                         EG - Egypt             SP - Spain             
                         FI - Finnland          SU - Sudan             
                         FR - France            TH - Thailand          
                         HU - Hungary           UG - Uganda            
                         IN - India             US - United States     
                         IQ - Iraq              VN - Venesuela         
                         IY - Italy             ZA - South Africa      
                         KZ - Kazakstan         ZR - Zaire             
                         LA - Laos              
     93-96           Latitude in decimal degrees x 100.
     97              N or S for North or South hemisphere.
     99-103          Longitude in decimal degrees x 100.
     104             E or W for East or West hemisphere.
     106-112         Catchement size in square kilometers [km^2].
     114-118         Elevation in meters  (unknown values -99).
     120-123         First water year in record.
     125-128         Last water year in record.
     130             M or D for to note whether the original data was.
                     monthly or daily.  Data converted from daily data
                     may contain monthly values derived from some
                     interpreted daily values.

     Below is a description of the Global Runoff Data Centre (GRDC) 
     identification code.

     GRDC-Code (for example 1447150):
         1      = WMO-Region (1 = Africa)
          4     = GRDC-Country code (4 = Congo)
           47   = GRDC-Subregion; main river basin (47 = Zaire/Congo)
             150= GRDC-Station code

     The length of records, in each G#######.FLR data file, is 126 characters 
     long and the data values are spaced delimited.

     The record format and parameters are:

     column #    parameters
         1-6     wyear
         7-16    October flow  (missing flow data values -9999.00)
         17-26   Nov.    flow
         27-36   Dec.    flow
         37-46   Jan.    flow
         47-56   Feb.    flow
         57-66   Mar.    flow
         67-76   Apr.    flow
         77-86   May     flow
         87-96   Jun.    flow
         97-106  Jul.    flow
         107-116 Aug.    flow
         117-126 Sep.    flow

8.5  Related Data Sets.
     There are other streamflow data sets generally available.
     Some prominent examples:
     Hydro-Climatic Data Network:  Streamflow data set
             USGS Water-resources investigations report 93-4076
     Wallis, J.R., Lettenmaier, D.P.,  and Wood, E.F., 1991. A Daily Hydro-
             Climatological Data Set for the Continental U.S. Water Resources 
             Research Bol. 27(7)1657-1663.
     Global Runoff Data Centre (GRDC):
             Global Runoff Data Centre
             Bundesanstalt F|r Gewasserkunde
             Kaiserin-Augusta-Anlagen 15-17
             W-5400 Koblenz
             Federal Republic of Germany
             Fax: +49 261 1306302
             Tel:  +49 261 1306-1
     European Water Archive
             Institute of Hydrology
             Crowmarsh Gifford, 
             Oxon  OX10  8BB
             United Kingdom

                         9.  DATA MANIPULATIONS

9.1  Formulas.

     9.1.1  Derivation Techniques/Algorithms.
            Where monthly averages had to be calculated from daily
            averages, an algorithm was employed to handle gaps in the daily
            record.  The days in the gap were linearly interpreted if
                a)   (# days in gap <= 20) & (%change < 10%)
             or b)   (# days in gap <= 10) & (%change < 50%)
            The daily values for a given month were then averaged if

                a)   # original measured values >=  2/3 # days in month
             or b)   (total # vals (meas.+interp) >= 3/4 # days in month) &

                1) (# meas >= 1/10 # days in month) & (cum. %change <= 10%)
             or 2) (# meas >= 1/2 # days in month) & (cum. %change < 50%)

            Otherwise monthly value classified as missing (-9999.00)
9.2  Data Processing Sequence.

     9.2.1  Processing Steps and Data Sets.
            Daily flow data were converted to monthly flow data using
            the algorithm in 9.1.1
            The monthly tables were reorganized from the January to
            December original order to a water year format of October
            to September.  Water years with at least one monthly value
            were retained and any missing values were filled in with
            -9999 as a no data value.
     9.2.2  Processing Changes.


9.3  Calculations.

     9.3.1  Special Corrections/Adjustments.

            See section 9.1.1.

9.4  Graphs and Plots.


                          10.  ERRORS

10.1  Sources of Error.
      Many gaps in the record were caused by freezing conditions,
      and ice bound flows. Standards of observation have changed through
      time but this information is not available. European observations
      during World War I and II, however, might be suspect. No corrections 
      have been made for the anthropogenic effects of damming and pumping but 
      these effects are often readily apparent (as on the Nile around the time 
      the Aswan High Dam was constructed). Climate modelers are cautioned that 
      this data set is not representative of all, particularly more arid, 
      regions of the world so reproduction of these runoffs, although 
      laudable, does not guarantee effective global climate simulation. In 
      addition, small basins are not well represented and likely would show 
      greater interannual variability.

10.2  Quality Assessment.

      10.2.1  Data Validation by Source.

              Not available.

      10.2.2  Confidence Level/Accuracy Judgment.

              Not available.

      10.2.3  Measurement Error for Parameters and Variables.

              Not available.

      10.2.4  Additional Quality Assessment Applied.

              Not available.

                             11.  NOTES

11.1  Known Problems With The Data.

      None reported at this revision.

11.2  Usage Guidance.


11.3  Other Relevant Information.


                           12.  REFERENCES

12.1  Satellite/Instrument/Data Processing Documentation.


12.2  Journal Articles and Study Reports.

      Corbett, D. M., and others, 1945. Stream-gauging procedure: U.S. Geol. 
         Survey Water-Supply Paper 888, 245 p.
      Max-Planck-Institut fur Meteorologie, Report No. 100. Discharge
         data from 50 selected rivers for GCM validation, L. Dumenil,
         K. Isele, H.-J. Liebscher, U. Schroder, M. Schumacher, K. Wilke.
      USGS Office of Water Data Coordination, 1977. National handbook of 
         recommended methods for water-data acquisition, USGS, Reston VA.
      World Resources Institute, 1990, World Resources: 1990-91,
         Oxford University Press, 383p.

12.3  Archive/DBMS Usage Documentation.

      Contact the EOS Distributed Active Archive Center (DAAC) at NASA Goddard 
      Space Flight Center (GSFC), Greenbelt Maryland (see Section 13 below).
      Documentation about using the archive or information about access to the 
      on-line information system is available through the GSFC DAAC User 
      Services Office.

                             13.  DATA ACCESS

13.1  Contacts for Archive/Data Access Information.

      GSFC DAAC User Services
      NASA/Goddard Space Flight Center
      Code 902.2
      Greenbelt, MD 20771

      Phone:     (301) 286-3209
      Fax:       (301) 286-1775
      Internet:  daacuso@eosdata.gsfc.nasa.gov

13.2  Archive Identification.

      Goddard Distributed Active Archive Center
      NASA Goddard Space Flight Center
      Code 902.2
      Greenbelt, MD 20771

      Telephone:  (301) 286-3209
      FAX:        (301) 286-1775
      Internet:   daacuso@eosdata.gsfc.nasa.gov

13.3  Procedures for Obtaining Data.

      Users may place requests by accessing the on-line system, by sending 
      letters, electronic mail, FAX, telephone, or personal visit.

      Accessing the GSFC DAAC Online System:

      The GSFC DAAC Information Management System (IMS) allows users to 
      ordering data sets stored on-line.  The system is open to the public.

      Access Instructions:

      Node name:  daac.gsfc.nasa.gov
      Node number:
      Login example: telnet daac.gsfc.nasa.gov
      Username:  daacims
      password:  gsfcdaac

      You will be asked to register your name and address during your first

      Ordering CD-ROMs:

      To order CD-ROMs (available through the Goddard DAAC) users should 
      contact the Goddard DAAC User Support Office (see section 13.2).

13.4  GSFC DAAC Status/Plans.

      The ISLSCP Initiative I CD-ROM is available from the Goddard DAAC.


14.1  Tape Products.


14.2  Film Products.


14.3  Other Products.


                       15.  GLOSSARY OF ACRONYMS
CD-ROM       Compact Disc Read Only Memory.
DAAC         Distributed Active Archive Center
EOS          Earth Observation System
GCM          Global Circulation Model.
GRDC         Global Runoff Data Center.
GSFC         Goddard Space Flight Center
IMS          Information Management System
ISLSCP       International Satellite Land Surface Climotology Project
NASA         National Aeronautics and Space Administration
WMO          World Meteorological Organization.