Water scarcity and abundance, water productivity and their relation to poverty - Water Scarcity, Livelihoods and Food Security - page 22

and Ogilvie, 2009). The rangelands of the dry, central Limpopo are also grazed
at low intensity but the pastoralists are sedentary (PN62) (Sullivan and Sibanda,
2012).
It is important to distinguish aridity from “physical water scarcity” as defined
in the CA (“when more than 75% of the river flows are withdrawn for
agriculture, industry and domestic purposes”) (Molden, 2007). The former
focuses on rainfall, the latter on the extent of blue water withdrawals.
The CPWF had few projects in catchments or sub-basins in arid areas. Most
projects were located where other dimensions of water scarcity were more
important.

Seasonal unreliability
Outside of arid regions, average annual rainfall is adequate for agriculture of
some kind, but annual averages can conceal more than they reveal. Rainfall
may fail when it is most needed, and the more unreliable the rainfall, the more
frequent failures. Unreliable rainfall can reduce productivity and favor extensive
use of land to reduce the risk, for example low planting densities. Unreliability
may affect contrasting social groups differently and with varying levels of
severity.
Unreliability may be normal or exceptional. Where it is normal, farm
families are likely to have developed multi-layered mechanisms to cope. If
unreliability becomes extreme, coping mechanisms may fail and threaten
family survival. Seasonal unreliability of rainfall is only part of the story. Risk
of loss is higher when farm families lack coping mechanisms and when
investment in water infrastructure and management is inadequate. The same
problems of seasonal unreliability may affect different social groups in different
ways.
There are several dimensions to the problem of seasonal unreliability, some
of them closely related:

• Seasonality of the rainy season (one or more of late onset, early termi-

nation, extended dry periods within the season, unfavorable temporal
distribution or outright failure);

• Seasonality of the supply of stored water (inadequate quantity of stored

water to grow crops or fodder in the dry season);

• Seasonality of the demand for stored water (the demand increases in years

when the rainy season is short, unreliable, or when failure of rainy season
crops due to pests or disease forces farmers to resow);

• Seasonality of water quality (excess of saline water when freshwater is

needed [for rice] or excess of freshwater when saline water is needed [for
shrimp]);

• Seasonality of river flow and flooding (inadequate or excessive pulsing of

river systems to support catch fisheries or aquaculture; unanticipated and
excessive seasonal flooding that destroys crops and livestock). Many