with the famous irrigation systems of southern Arabia, but also the fields must
gradually have been raised by siltation relative to the level of the inlet canals, thereby
slowing down flow even more and encouraging further sedimentation. Because rivers,
canals and fields were all gradually aggrading, the entire hydraulic landscape required
considerable effort to constrain this to within an acceptable amount, or alternatively to
remodel the system so that it continued to function.
RIVERS AND CANALS AS TRANSPORTATION NETWORKSIt has long been recognised that canals and channels were as important as transport
routes as they were for conducting irrigation water, a theme that remains central
to the so-called ‘Mesopotamian Advantage’ (Sauren 1966 : 36 ; Algaze 2008 ). The
branching ‘low sinuosity’ river systems were ideal for the mobilisation of bulk goods
from city to city (Figure 2. 6 ; Algaze 2008 : 51 – 62 ; Potts 1997 : 28 ) so that not only did
they provide an excellent distribution system, but also like many modern road systems
they functioned as a network that was capable of being extended. Thus the large
Iturungulcanal of probably third millennium BC‘provided a connective link in an
enclosing network of natural and artificial watercourses serving the major southern
Mesopotamian cities’ (Adams, 2008 : 6 , 9 ; Adams 1981 : figs 18 , 21 ; Steinkeller 2001 : 40
map 1 ). Furthermore, any open water marshlands would also have increased the
connectivity of the channel system (Pournelle 2007 ). Such increased connectivity is
important because it indicates how just one extra link in a network can improve the
overall connectivity of that system thereby making it much more efficient to transport
goods throughout the entire network.
Apparently the scale of grain shipments during the Ur III state was so significant
that perhaps half of the gross harvest from Umma’s cultivated lands, according to state
records, moved by barge especially between the major Ur III urban centres of Ur, Uruk
and Nippur (Sharlach 2004 : 27 , 161 ; Adams 2008 : 9 ). Nevertheless, the rivers and
–– Tony J. Wilkinson ––Figure 2.6Bulk transport of reeds by boat. Photo: V 009 , courtesy of the Gertrude Bell Archives.