RVR_FLOW.DOC
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.
\DATA\HYDR_SOL\RIVR_FLR\G_GAUGES.sfx
\DATA\HYDR_SOL\RIVR_FLR\G#######.sfx
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
given.
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
(1945)
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.
5.2.1.1 Tolerance.
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
details).
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,
Wallingford
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.
None.
9.3 Calculations.
9.3.1 Special Corrections/Adjustments.
See section 9.1.1.
9.4 Graphs and Plots.
None.
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.
None.
11.3 Other Relevant Information.
None.
12. REFERENCES
12.1 Satellite/Instrument/Data Processing Documentation.
None.
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: 192.107.190.139
Login example: telnet daac.gsfc.nasa.gov
Username: daacims
password: gsfcdaac
You will be asked to register your name and address during your first
session.
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. OUTPUT PRODUCTS AND AVAILABILITY
14.1 Tape Products.
None.
14.2 Film Products.
None.
14.3 Other Products.
None.
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.