Freshwater is becoming scarcer and many coastal communities are turning to desalination as a supplement for their freshwater supplies. However, desalination is an energy expensive process and in order to have the energy to desalinate water the power plants require more freshwater to produce the additional energy required to run the desalination plants. So when policy was enacted which implemented the desalination practices for an increase in the supply of freshwater there was an unintended consequence, increased energy and water usage, that is nearly unable to be adjusted for in the system. This water/energy nexus is very taxing on the system and decreases its net freshwater production and exacerbates the water shortage problem for the community.
The diagram below shows the two cycles and how they contribute to the dynamic system of freshwater desalination and its effect on the water and energy usage of the community. Please note that the Water/Energy Nexus cycle is reinforcing and causes continued increase in energy usage while the Seawater Supplementation cycle is balancing and seeks to account for and correct any shortage in the freshwater supply.
Hello Megan! Good choice of problem, one I think is particularly relevant to a country like Malta, where freshwater resources are particularly low and almost 100% of energy production is non-renewable (i.e. involves fuel combustion which in turn makes use of water resources).
ReplyDeleteThe diagram is well laid out and one can easily identify the loops that are working in opposite directions. If I had to suggest any changes to the CLD they would be the following:
i) change 'water use for energy production' to simply 'water use' as the arrow going from 'energy use' to this variable already explains that the water is being used as a result of increased energy demand
ii) consequently link agricultural, municipal and industrial factors to the 'water use' variable
This may be a better approach as it keeps your variables shorter and maybe also removes the redundancy of explaining what the water is being used for when the link to the previous variable explains that too.
This however is something that you did not need to bother much about in a simple two loop diagram so I can see why you laid it out as it is above. I am just making the above suggestions should you decide to further expand the CLD in the future. Well done in my opinion!!