Project Monitoring Network

Necessity

Experts in water resources management point out the difficulties in water management projects in their publications and in their lectures at conferences.

Difficulties

They underline that national and international organisations of development cooperation often have the problem that no or insufficient hydrological and meteorological data are available. But these data are of great importance for reliable calculations in the areas of

  • agriculture (irrigation and drainage, desalination of soil)
  • housing water management (water supply and sanitation)
  • erosion control
  • flood protection
  • water balance
  • nature conservation (establishment of borders for marshlands, nature reserves, national parks)
  • energy industry
  • rural and urban measures (road and path construction, sewerage systems)

Water deposits usable for these purposes are often not recorded in quantity, quality, their geographical and seasonal allocation. Frequently, available data have gaps. Professor Dr.–Ing. H. Wildenhahn is describing this in his reference book “Wasserwirtschaftliche Meß- und Auswerteverfahren in Trockengebieten”, published by DVWK in 1990 [1].

Situation Unchanged

That this situation has not changed until today becomes clear in the report “Data shortage in Africa”, by Volker Mrasek in “Deutschlandfunk” of 24th August, 2005.  Swedish hydrologist and engineer Rikard Lidén states at a seminar at the World Water Week at Stockholm in 2005 that Africa is suffering not only from water shortage but also from data shortage. Sten Bergström, leader of the research group of the Swedish Weather and Water Service at Norrköping / Sweden is quoted with the following words: “Sometimes, data are lacking because they were never measured. Sometimes, gauging stations are destroyed during civil wars. But mostly, water departments are lacking money to employ people for measuring and maintaining the equipment. This is a real problem.” says Rikard Lidén, this is a growing problem, “since data quality is deteriorating and many measurement series are not continued nowadays. So the engineer warns that water shortage in Africa could aggravate, describing an example from the south eastern corner of the continent ...”

Before the beginning of a project

there are the following questions and problems:

  • Are there any data for the project area?
  • Where can I get data for the project area?
  • How reliable, representative or comparable (same measurement method) are these data?
  • Can the gaps in the series of measurements be closed, e.g., by setting up separate gauging stations or by transferring data from comparable areas?
  • The search for data in the country itself is highly time- and money-consuming without guarantee for success.

Even if there was enough time before the start of the project to set up gauging stations and to carry them on during the project, raised data will not have the same statistical meaningfulness as measurement series over many years. For water resources management, planning requires measured values over 10 to 30 years. The longer the period of observation time the more convincing are the results.

Station Density

Comparison of Station Density in Germany and Africa

Compared to Germany, the net of hydrological and meteorological measuring stations in Africa is of low density. Thus, the covered area of each measuring station is very large and the meaning of the data correspondingly low. Illust. 1 shows the comparison of area per weather station in Africa and in Germany.

Weather Stations

In Africa, one WMO weather station covers an area of 27,347 km². Altogether, there are 1,108 WMO weather stations on the continent. In Germany, the covered area per WMO weather station is 1,244 km². There are 287 WMO weather stations operated in Germany.

You can find a table with the number of WMO weather stations in some African countries here

Gauging Stations

In Africa (without the area of Sahara), there are 888 gauging stations in an area of 21,300,000 km². Because the Sahara is practically  drain-off free, the area of the continent is reduced by that area. Illust. 2 shows the area of Africa without Sahara and that of Germany with the existing number of gauging stations.

Both illustrations clearly show at how few locations on the African continent measure hydrological and meteorological data.

WMO Weather Station
Country Area in km² Number of Stations¹ Area per Station in km²
Algeria 2,381,741 83 28,696
Angola 1,246,700 32 38,959
Benin 112,680 6 18,780
Botswana 582,000 19 30,632
British Islands Atlanic   2  
Burkina Faso 274,200 11 24,927
Burundi 27,834 2 13,917
Cameroon 475,442 18 26,413
Central African Republic 622,984 14 44,499
Chad 1,284,000 16 80,250
Comores 1,862 4 466
Democratic Republic of the Congo 2,345,410 57 41,148
Djibouti 23,200 2 11,600
Egypt 1,001.449 54 18,545
Equatorial-Guinea 28,051 2 14,026
Eritrea 121,144 4 30,286
Ethiopia 1,127,127 17 66,302
Gabun 267,667 13 20,590
Gambia 11,295 11 1,027
Germany 357,114 287 1,244
Ghana 238,537 21 11,359
Guinea 245,857 12 20,488
Guinea Bissau 36,125 4 9,031
French Islands in Indopazific 22,225 10 2,223
Ivory Coast 322,460 14 23,033
Kenya 582,646 25 23,306
Lesotho 30,355 3 10,118
Liberia 111,370 2 55,685
Libya 1,775,500 22 80,705
Madagascar 587,041 26 22,579
Malawi 118,480 23 5,151
Mali 1,240,192 20 62,010
Mauretania 1,030,700 16 64,419
Mauritius 2,040 5 408
Morocco 446,550 35 12,759
Mosambique 801,590 23 34,852
Namibia 824,292 15 54,953
Niger 1,267,000 16 79,188
Nigeria 923,768 33 27,993
Rwanda 26,338 5 5,268
São Tomé and Príncipe 1,001 2 501
Senegal 197,722 12 16,477
Seychelles 455 5 91
Sierra Leone 71,740 9 7,971
Somalia 637,657 22 28,984
South Africa 1,219,912 173 7,052
Sudan 2,505,810 39 64,252
Swasiland 17,363 1 17,363
Tanzania 945,087 21 45,004
Togo 56,785 9 6,309
Tunisia 163,610 22 7,437
Uganda 241,040 12 20,087
Zambia 752,614 36 20,906
Zimbabwe 390,757 41 9,531

1 Quelle: Deutscher Wetterdienst Hamburg, Stand 13.05.2008