Water Security Modeling Using Systems Dynamics
The Nile River Basin is confronting large scale dynamic challenges involving the confluence of tremendous population growth and potential declines in water resources. Sources of uncertainty persist about future climate change, particularly with respect to levels of greenhouse gas emissions. Avoidance of conflict within the region during the 21st Century will require attention to the development of a comprehensive water management system. Given the potential effects of climate change, this system must consider the utilization of water for enhanced energy capacity in the Basin while maintaining an equitable distribution of water based on anticipated regional changes in the water capacity of the region (CAN Military Advisory Board 2014, see http://www.cna.org/sites/default/files/MAB_2014.pdf
). Insofar as the vast majority of water used annually is earmarked for agricultural production, anticipated changes in population will have to be regulated and managed within the Basin’s water system. Moreover, insofar as evidence suggests that precipitation will likely increase in upstream countries prior to 2050, the systemic management of stream flow will be critical to divert water into meaningful uses in order to avoid the negative effects of inundation. The Nile River Basin Initiative (http://www.nilebasin.org/
), as a regional forum of ten African countries established for the purpose of managing resources, will be critical in the evolution of a water management system for the Basin. If successful, this forum will lead to regional policies capable of managing the allocation and utilization of water in a manner that is equitable and supportive of all ten countries. Such policies will need to focus on issues associated with the dynamic association between water availability, crop yield, and population growth in the context of climate change.
System behavior, often unanticipated, is typically the direct consequence of purposive social action undertaken within the context of extant social structures (see Merton, at http://www.d.umn.edu/cla/faculty/jhamlin/4111/Readings/MertonSocialAction.pdf
) . Insofar as social action reflective of different policies designs will result in potentially different outcomes, system dynamics (http://www.systemdynamics.org/what-is-s/
) becomes a viable analytical methodology with which to evaluate and explain the complex behavior of social systems over time. System dynamics involves the creation of computer-aided simulation models capable of generating system behavior that is reflective of various hypothesized policy strategies. These scenarios produce outcomes capable of informing stakeholder decisions on the relative value of various policy designs through the definition of system boundaries and the analysis of simulated implementation strategies. The models provide a direct approach to testing stakeholder assumptions with the intended goal, through the configuration of structured feedback mechanisms among a set of system variables, of identifying behavior capable of sustaining social systems.
Staff associated with the USMA Center for Nation Reconstruction and Capacity Development (CNRCD) have undertaken research on the Nile River Basin with attention directed toward the effects of water resource constraints on sustainability, security, and conflict. With support from the Engineering Research and Development Center’s (ERDC) Coastal and Hydraulics Laboratory (http://chl.erdc.usace.army.mil/
), CNRCD staff have established joint senior capstone projects involving undergraduate students at West Point (Dept. Systems Engineering) and Columbia University (Earth Institute) to examine to examine the impact of environmental and human factors on the carrying capacity (streamflow) of the Nile River throughout the 21st Century (see http://www.usma.edu/cnrcd/SitePages/News%20and%20Events.aspx
). In this project, we gathered estimates from 33 General Circulation Models (GCM), inclusive of Representative Concentration Pathways (RCP) 4.5 and 8.5, within a system dynamics (Vensim) model in order to model the dynamic interplay between climate change and streamflow for the Nile River Basin. We subdivided the time periods into 30-year intervals for 2010-2039 (early century), 2040-2069 (mid century), and 2070-2099 (late century). Water data were drawn from the Food and Agriculture Organization of the United Nations (2010, http://www.fao.org/nr/water/aquastat/main/index.stm
) and the Encyclopedia of the Earth via the water profiles on Ethiopia, Sudan, and Egypt (http://www.eoearth.org
). Additional sources were used to validate these figures (Awulachew 2008; Ahmed 2007). Estimates of temperature and precipitation in each of these four regions were drawn from 33 independent General Circulation Models (GCMs) and two Representative Concentration Pathways (RCPs) were drawn from NOAA/OAR/ESRL Physical Science Division (see Taylor et al. 2012). Preliminary findings of this project were presented to faculty at Addis Ababa and Bahir Dar Universities following attendance at the International Food Policy Research Institute Conference (IFPRI) in Addis Ababa during May 2014. Findings from this project were also presented in Delft, Netherlands at the International System Dynamics Conference (http://conference.systemdynamics.org/current/upload/tentsched.html
) by students representing the two schools and one faculty member.
Our preliminary analyses suggest that, much like other GCM studies on the Nile River Basin, temperature will increase throughout the Basin during the 21st Century while estimates for changes in precipitation will vary by region.
The potential impact on Egypt is likely to result in demonstrably less water regardless of the amount of greenhouse gasses present (RCP); though the country, and region overall, appear to do better under scenarios with RCP levels reflective of an average between 4.5 and 8.5. These findings are consistent with other studies, which suggest that Egypt is likely to witness diminished stream flow, particularly after 2050 (Yates and Strzepek 1998; ElShamy et al. 2009; El Saeed 2012).