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Brown Bags: Ecosystem Modeling and Radar-based Levee Monitoring

September 2015
Levee Monitoring

The Brown Bag Series of monthly seminars are used as an educational tool providing the latest environmental information to the science community and other interested parties. They are a collaborative effort of the Delta Stewardship Council’s Delta Science Program, the Department of Fish and Wildlife’s Ecosystem Restoration Program and the State Water Resources Control Board’s Surface Water Ambient Monitoring Program. The hour-long discussions are usually scheduled during the noon hour allowing the audience to indulge in brown bag lunches while learning about specific Delta issues.


Integrated Ecosystem Modeling for Adaptive Management


Integrating ecosystem modeling as an adaptive management tool was the topic of a July 7 Brown Bag Seminar where Dr. John Wolfe, a vice president with LimnoTech, a Michigan-based environmental engineering firm, presented lessons learned from the Great Lakes where his company has been using ecological forecasting models since the 1970s. Wolfe also described the benefits of integrated modeling as part of an adaptive management approach that can be applied to the Bay-Delta system.


“There are just as many interests to balance and promote in the Great Lakes as there are in the Central Valley,” Wolfe said, “balancing water supply, water quality, recreation, commercial fisheries, navigation, and health of the ecosystem. It’s a real challenge having multiple actors with multiple models and multiple goals. One of the biggest challenges is uncertainty. Even if we have models we don’t know that they’re exactly right. We need to make decisions anyway, monitor the outcomes, and somehow be prepared to change.”


The recent re-emergence of nuisance algae in the Great Lakes demonstrated the need to incorporate adaptive management into the decision-making process. The city of Toledo, Ohio had to shut off its water supply because it was choked with microcystis, a toxic blue-green algae.


“There were models in place and limits in place for phosphorous in the Great Lakes for 25 years that shouldn’t have happened, so technical people and decision-makers had to go back to the drawing board,” Wolfe said.


He added that there’s no modeling in decision-making without good data, shared data, and accessible data. To that end, the Great Lakes Observing System (GLOS) a binational, non-profit clearinghouse for data, combining providers and users was formed. Its mission is to link users and providers of data, information and knowledge in a way that supports sound decision-making; focusing on ecosystem health, public health and water security, maritime operations, climate change and natural hazards.


In the Delta, Wolfe suggested coordination could be promoted by a community modeling hub, a shared repository of data and models that could set standards of software practice providing a forum for comparison of model results and involving stakeholders up front.


“Things will change, and systems will evolve on a multi-decadal scale,” Wolfe said. “Integrated data and models can help us understand those changes and support decisions to revise those targets in the future.”


For more details and to view the video from the seminar, click here.


Sacramento Delta Levees - Radar-based Monitoring from 41,000 Feet


Since July 2009, radar-sensing aircraft have flown over the Delta in a study to determine the feasibility of radar remote sensing to monitor levee deformation using one of NASA’S premier airborne science instruments.


“Radar-remote sensing surveys can give large-swath images of the area rapidly and provide consistent monitoring,” said Dr. Cathleen Jones of the Jet Propulsion Laboratory during another Brown Bag seminar in July. “You use the same technique to monitor every levee in the area. You can detect changes that occur on very small scales and on very small amounts.”


“Radar can see through clouds, fire, smoke, and haze,” she said. “You can rapidly see the ground regardless of day, night, or light conditions. Radar is also very good at detecting standing water which is quite useful in a flood.”


The radar-sensing aircraft always flies at the same altitude and measures change in distance to the land or water surface between the first and second flights. This information is then used to determine the amount of subsidence or other damage that has occurred.


“This technology could be very useful for identifying change on earthen levees,” Jones said.


High resolution radar technique has successfully identified damages and/or subsidence of levees and lands in the Bradford, Jersey and Sherman Islands. Validation of the INSAR method is ongoing with field on-ground subsidence measurement.


For more details and to view the video from the seminar, click here.

Coequal goals

The Delta Stewardship Council was created in legislation to achieve the state mandated coequal goals for the Delta. "'Coequal goals' means the two goals of providing a more reliable water supply for California and protecting, restoring, and enhancing the Delta ecosystem. The coequal goals shall be achieved in a manner that protects and enhances the unique cultural, recreational, natural resource, and agricultural values of the Delta as an evolving place." (CA Water Code §85054)