CALIFORNIA: THE LOLL BEFORE THE STORM
There is an old naval and merchant marine engineering adage that states that it is most important to fix a loll condition before fixing a list condition. List is a side to side shift in the ship’s center of gravity relative to the center line causing the ship to heel at a certain angle. A listing ship can still be stable because the ship’s center of gravity remains below the ship’s metacenter1 and as a result, the righting moment – the force that tends to return the ship to an upright condition – remains positive.
Loll, however, is entirely different. In a loll condition, the ship’s center of gravity moves above the metacenter, resulting in a negative righting moment that causes the ship to continue to roll over. In layman’s terms, this means that any motion of the ship that would tip her to one side is further reinforced by the forces acting on the vessel. It is an extremely dangerous condition because without immediate action, the ship is doomed to capsize.
Interestingly, both list and loll present themselves with the same symptom – the ship is tipped to one side. In a list condition, the remedy is to simply move a portion of the ship’s ballast to the “high” side. However, if the condition is actually loll, that action is catastrophic. In the case of loll, the movement of the ballast will tip the ship to the other side and to a greater angle. The “remedy” exacerbates the negative righting moment associated with the loll condition, causing an even greater likelihood that the ship will capsize.
How then, can we make a correct determination on the course of action? The answer lies in understanding how the ship acts as a dynamic system. Under a list condition, the ship remains in a tight movement envelope that can be felt. The roll period – the time it takes for the boat to roll from port to starboard – can also be measured. A stable ship returns to an upright condition rapidly.
Loll on the other hand, increases that roll period. The ship becomes sluggish and seemingly hangs at the tipped position for longer periods of time as the response to disturbing forces slows down. As a result, the ability of the ship to right itself is compromised. In these conditions, it is imperative to take immediate action to prevent it ultimately causing the loss of the vessel.
TIPPING THE CALIFORNIA WATER SITUATION
Not unlike the forces that result in list and loll conditions in a ship, forcing events are those conditions that reinforce certain outcomes. We often hear about forcing events when describing how the climate is changing and the subsequent impacts on ecosystems. From the study of large-scale networks, the concept of “critical slowing down” can be applied to assess the response of natural systems in the face of destabilizing forces. Critical slowing down reduces the ability of the system to respond to increasingly variable inputs, such as increased volatility in water cycles or increased temperatures. Statistically, it is represented as an increase in the variance of the data2, but from an observational perspective, systems getting close to tipping points are slower to react to destabilizing forces. And just as the ship in a loll condition responds slower and slower until it catastrophically capsizes, ecosystems and climate patterns get slower to return to their “normal” condition, until they suddenly jump to a new equilibrium point, a “new normal” condition.
ARE WE THERE YET?
The question for water managers in California is whether the current conditions are indicative of an equilibrium change.
The graph above shows the percentage of California’s land mass under specific drought conditions for the last 15 years. In the early 2000s, the state’s climate recovered from drought conditions quickly – the period of drought was relatively short and the intensity was low. As the century has progressed, however, the period of recovery has dramatically increased, and the depth of the drought – as indicated by the drought severity categories – is increasing.
California is acting like a ship in loll where the response to disturbances is getting slower and deeper. Just as a systems scientist would recognize this as a critical slowing down of response, the message for California water managers is clear: we are in danger of capsizing, or jumping to a new equilibrium condition with respect to water in California.
Of course the American southwest has seen these shifts in the past. Research indicates that longterm droughts are not unusual in this region, and in fact have occurred throughout earth’s history4 – most recently in what is known as the Medieval Climate Anomaly.5 In the last 50 years, flows in the Colorado River have been decreasing in a pattern distressingly similar to those in the 12th century. The fundamental difference today is that the Colorado River basin supplies water to nearly 40 million people – not the hundreds of thousands of Anasazi displaced during the Medieval Climate Anomaly.
To ensure sustainability, and to prevent a capsizing of our water delivery systems, it is imperative that we rethink the technical processes associated with water delivery. This means moving from a system designed in – and fundamentally unchanged since – the early 20th century, to a system that maximizes our understanding of how, where and when we use water. We must improve the data systems associated with water.
FATHOM modernizes the data and business processes associated with meter reading, billing, customer service, asset management and utility operations by integrating utility data into a geo-temporal data model. Through advanced data analysis and presentment, customers and utility staff are afforded greater insight into consumption use and patterns, allowing sustained resource protection, and increased customer service levels. Most importantly, FATHOM finds revenue in existing data systems that offsets the revenue destruction associated with conservation and efficiency.
Our water systems must change to meet the reality of the new normal on the horizon. Fortunately there
are tools like FATHOM that can ease and facilitate that transformation.
1The “metacenter” is an imaginary point at the intersection of a line drawn through the center of gravity along the centerline of the ship and a vertical line drawn through the ship’s center of buoyancy.
2Scheffer et al. “Early-warning signals for critical transitions”, Nature 461, 53-59 (3 September 2009) doi:10.1038/nature08227.
3Data from http://droughtmonitor.unl.edu/MapsAndData/DataTables.aspx?state,CA
4Peter J. Fawcett et al., “Extended Megadroughts in the Southwestern United States during Pleistocene Interglacials,” Nature 470 (February 24, 2011), doi:10.1038/nature09839
5D. M. Meko, C. A. Woodhouse, C. A. Baisan, T. Knight, J. J. Lukas, M. K. Hughes, and M. W. Salzer, “Medieval Drought in the Upper Colorado River Basin,” Geophysical Research Letters 34 (2007): L10705, doi:10.1029/2007GL029988