a relevant sub-basin in the national Nile area, counterpart
staff has developed a poster illustrating the relative contribution
of the various tributaries to the main river. The map uses
a hill-shaded Digital Elevation Model (DEM) as background
to show the relief of the terrain.
distinction is made in hydrology between blue and green
water. Blue water refers to the water passing through aquifers
and watercourses. It represents that part of the water resource
most readily available to satisfy societal needs.
water is the fraction of the rainfall that evaporates. It
constitutes the water supply for all non-irrigated vegetation,
including forests, woodlands, grasslands, and rainfed crops.
It further includes evaporation from the soil and wet surfaces.
the Blue Water Posters serves multiple purposes. It is used
to quality control hydro-meteorological data sets and to
identify systematic errors - like missing months or erroneous
units. The poster also trains counterpart staff in using
GIS for visual explanation. The final product is an effective
means for explaining the hydrology of the sub-basin to stakeholders
and decision makers. See
country posters: Ethiopia Rwanda Sudan Tanzania