Digital Atlas of the World Water Balance, Version 2.0, May 1998
World Data on CD-ROM

Center for Research in Water Resources
The University of Texas at Austin

Table of Contents

• Introduction
• List of Coverages
• Attributes of Climate Coverages
• Attributes of Runoff Coverages
• Attributes of Political Coverages
• Monthly Climate Animations

Introduction

Data for each continent are presented in folders entitled Africa, Asia, Austral, Europe, Namerica, and Samerica, from which data from any region can be selected using Arcview selection tools. Another folder shows data for Texas which is used as a sample area for data display on a fairly small region since data display at continental scale can be quite time consuming when the data are viewed directly on the CD-ROM drive. Procedures for clipping out data for particular countries are presented in Exercise 1 in the Education Folder. The data describe precipitation, temperature, net radiation, soil water capacity, runoff and political boundaries for the earth. Each folder contains an Arcview 2.1 and 3.0 .apr project files that be used to display the data, which are suffixed 2 or 3, respectively, to refer to the version of Arcview that they apply to, e.g. africa2.apr displays data for Africa in Arcview version 2 and africa3.apr does the same for Arcview Version 3.0. If possible, view the data using Arcview version 3.0 project files because the cartography is better.

List of Coverages
 
There is a separate directory for each of the six continents of the world (Africa, Asia, Austral, Europe, Namerica, Samerica). The data in each folder have been compressed to afrdata.zip, asdata.zip, audata.zip, eudata.zip, nadata.zip and sadata.zip, respectively. The files can be uncompressed using the pkzip utility available on this CD-ROM. Each folder contains the following information:
 

Attributes of Climate Coverages

The fields in the attribute tables of the Climate coverages are described as below:

Precipitation: mean monthly values in mm (Pjan, Pfeb, Pmar, Papr, Pmay, Pjun,Paug, Psep, Poct, Pnov, Pdec) and mean annual value as Pann in mm.

Temperature: mean monthly values in degrees C (Tjan, Tfeb, Tmar, Tapr, Tmay, Tjun,Taug, Tsep, Toct, Tnov, Tdec) and mean annual value as Tann in degrees C.

Net Radiation: mean monthly values in W/m^2. These values are attributed in the views as Jan, Feb, Mar, Apr, May, Jun, Jul, Aug, Sep, Oct, Nov, Dec and the mean annual value in W/m² as Ann. In the attribute table, net radiation is denoted by Nr, and the various monthly values are denoted by Nr_jan, Nr_feb, ..., Nr_dec, and the mean annual value by Nr_ann. In order to provide for other kinds of net radiation estimates, the incoming solar radiation at the land surface is also attributed in the tables, as Swd (Short-wave downward), and the monthly and annual values are likewise denoted by Swd_jan, Swd_feb, ..., Swd_dec, and Swd_ann.

Soil Water Holding Capacity: value in mm as Whold

Attributes of Runoff Coverages

The runoff folder under the atlas directory contains a point coverage, Runoff.shp, with 160 runoff stations. Mean monthly and mean annual runoff for each station are given in cubic meters per second. The mean values were computed from monthly and daily runoff data obtained from the Global Runoff Center in Koblenz, Germany.

Each of the runoff stations has the following attributes:

Site: the location of the runoff station is given in terms of the station-id, station name, river name and country name (Dischar_id, Site, River, Ct). Country names are represented by two alphabetic characters which correspond to the codes (Fips_code) used in the political boundary coverages The longitude and latitude of the stations are also given in decimal degrees (lon_dd, lat_dd). 

Runoff: mean monthly values of runoff in m3/s (Jan, Feb Mar, Apr, May, Jun, Jul, Aug, Sep, Oct, Nov, Dec) and mean annual value (Annual) also in m3/s

Record: the period of record used in determining the mean values are documented as first month and year, (first_mon, first_year), as well as last month and year, (last_mon, last_year). The number of complete years of data is also given (Years). The source of the data for computing the mean values are also given as M for monthly and D for daily runoff data.
 
 

Attributes of Political Coverages

The Polit folder under the atlas directory contains the theme Cnty, which displays all political regions of the world.

Political: the political boundaries of the countries of the world according to the FAO definition of boundaries. Attributes include the full and shortened versions of the name of the country (name, fips_code).

Area: the surface area each country is also given in square kilometers.

Climate Animations

Examples of the climate data for Africa are presented as monthly gif animations below. Click on the precipitation, air temperature, radiation figures to start the animation.

Annual Precipitation (mm) (click on map to see monthly animation)

Mean Annual Air Temperature (^oC) (click on map to see monthly animation)

Mean Annual Net Radiation ( W/m²) (click on map to see monthly animation)

Soil water holding capacity (mm): constant value