Assessing the resilience of irrigation agriculture: applying a social-ecological model for understanding the mitigation of salinization

This paper creates and applies a computational model of irrigation agriculture in order to study the effects of salinization in Mesopotamia, with the model developed applicable to cases beyond that studied here. Scholars have long suspected that central and southern Mesopotamia present environments which limited agricultural production over the long-term. In regions such as central Mesopotamia, where salinization likely affected settlement and agriculture in different periods but was more manageable than in more southern regions, fallowing regimes, natural and engineered leaching, and decisions made on when to crop were strategies applied in order to limit the effects of salinization. In this paper, we assess the effectiveness of these coping strategies by incorporating projected climate, soil, and landscape conditions with agricultural practices. The simulation results not only demonstrate the effectiveness and limitations of inhibiting progressive salinization, but they can be compared with the archaeological record in order to determine if the results could reasonably be matched with past events and help to interpret settlement history.     

Shared rivers and interstate conflict

“The previous war in the Middle East was about oil, the next war will be about water.” Such predictions have been made regularly, and particularly with reference to the possibility of upstream–downstream conflicts in major rivers which cross interstate boundaries. A good case can be made that competition over water resources may exacerbate conflict and contribute to interstate violence. More than 200 river systems are shared by two or more countries. Many rivers run between countries with a history of conflict, where water plays an important part in the economic life of the country. The dramatic statements about ‘water wars’, however, have a weaker foundation. As resource optimists have pointed out, there is an abundance of water where it is not subject to wasteful uses, human ingenuity can overcome water shortages, and nations can cooperate rather than fight to resolve international water issues. This study is built on newly generated data on boundary-crossing rivers, which have been added to the Correlates of War contiguity dataset. Our results indicate that a joint river does indeed increase the probability of militarized disputes and armed conflict over and above mere contiguity. This risk factor is comparable in size to standard control variables, but much smaller than the effect of contiguity itself. Water scarcity is also associated with conflict, and the upstream/downstream relationship appears to be the form of shared river most frequently associated with conflict. But these results are not very strong and we do not have any systematic data on the issues involved in the shared-river conflicts.     

Some chronological implications of a fossil molluscan assemblage from a neolithic site at Brook,Kent, England

The later post-glacial history of a valley in the chalk escarpment near Brook, Kent, is described, based on molluscan stratigraphy, archaeological evidence and radio-carbon dating. Differences in size and colour banding, respectively, of fossil and living representatives of two species of land snails, Pomatias elegans (Müller) and Cepaea nemoralis (L.), are correlated with climatic change during the post-glacial period. The problems of the use of fossil shells of these species as samples for radiocarbon dating are discussed.