(see Sections 4.4.3 and 9.8.2) with consequences for livelihoods, nutrition, public health and well-being. Agricultural water withdrawal is used for irrigation, livestock and aquaculture (FAO 2016). In particular, irrigation makes up the majority of total water withdrawal (67 per cent) (United Nations World Water Assessment Programme [WWAP] 2016).
Scope and measurement Water withdrawal trends indicate how human use of fresh water has changed over time. At the global level, over the last century water withdrawal has increased (Figure 16.5). The changes to blue water withdrawal suggest how irrigation has increased over time. The ratio of agricultural water withdrawal to total water withdrawal within a country varies across the globe with factors such as climate and priority given to agricultural activity (Figure 16.6). The development of dams has contributed to anthropogenic water use and evaporation from storage of water in lakes or reservoirs. However, this type of water withdrawal is not currently reflected in the indicator discussed in this section (FAO 2016).
Figure 16.5: Trends in global water withdrawal by sector between 1900 and 2010 (km3
per year) 4 000 3 500 3 000 2 500 2 000 1 500 1 000 16 500 0 Year
Source: Adapted from FAO (2016). Industries
Figure 16.6: Proportion of total water withdrawn for agriculture