Principals of Ecological Engineering Design
Authors: John Bolte1 Gerrad Jones1, Desiree Tullos1, John Selker1
1Biological & Ecological Engineering Department, Oregon State University
A Design Strategy for Ecological Engineers
Design is fundamental to the practice of ecological engineering. Below, we provide some guidance on approaching design problems in ecological engineering, including a brief discussion of design process, a stepwise flowchart to identify key steps in the process, and guidelines for documentation produced at various steps in the process.
Design is a creative process that identifies problems and constraints, develops solutions to overcome those constraints and address the problem in a cost-effective way. These solutions should not only work, they must meet the needs of the client, be based on accepted engineering analyses and methods, consider economic, social, and ethical dimensions of the design, and be communicated to the client in an effective manner.
Ecological engineering designs often incorporate additional constraints related to sustainability, system resilience, and need to provide a variety of ecosystem services, the geospatial nature of many ecological engineering problems, and the intrinsic complexity and variability associated with ecological systems.
The figure below provides a general summary of the design process, identifying important steps and concepts. Some of the key steps in this generalize design process are:
Define the Problem. Clearly state the problem and begin to identify various physical, ecological, economic, legal, social, and ethical constraints. Research the problem and identify appropriate engineering techniques to analyze possible solutions. Take a look at other solutions to the problem (or similar challenges) and analyze why they work – or don’t work. Your goal is not to copy others’ work, but to try out different perspectives and gather information on a problem.
Identify Needs and Constraints. Specify the requirements of the design as well as any constraints identified above. Clearly state the assumptions that you are using to simplify the calculations you are using to generate your design (e.g., this design assumes steady state conditions). Establish basic cost guidelines (time and materials). Understand legal requirements including permitting and other regulatory processes. Work with the client to understand their goals and constraints. Identify needs related to provision of ecosystem services.
Brainstorm. Come up with possible ideas and solutions to the design challenge. Encourage creative, informed exploration of possible solutions, without getting excessively bogged down in detail. Use drawings, sketches, or computer visualizations to help inform the process where appropriate. At the end of the session, pick a few (generally 3-5) alternatives that satisfy all the requirements and appear to be the best options for further analysis.
Select a Design. Typically, this will involve the development of a decision matrix that specifies the key design features, weights these aspects in relative importance, and evaluates each option against all the selection criteria. As a team, share and discuss the ideas you are focusing on and develop a list of advantages and disadvantages for each design. The pros and cons could spur further ideas or refinements. Evaluate the feasibility of each alternative. Identify potential unintended consequences. This typically involves development of an alternatives analysis, based on specified design criteria (e.g. effectiveness, cost, environmental impact, uncertainty and risk of failure, etc.) Review results with the client. Choose one design you want to move forward.
Prototype and Test. Building a model – either physical or numerical – of your design based on your plans is a vital part of the engineering design process. Start by sketching the process you will use to achieve your design. Lay out each and every step of the process in terms of their sequence, expected time required, testing of the step. Overall, the design process sketch should include time for testing, peer review, report development, and unanticipated delays. Typically, this will result in a Gantt chart or detailed calendar presentation of the engineering program. Your process will need to evaluate how your design meets the requirements and specifications for the project, including economic constraints and social suitability. Does it respect relevant regulations and address community values and ownership?
Once you’ve identified your design and test process, develop your prototype and test it out. This step allows you to see potential flaws, opportunities, or challenges that aren’t obvious. Refine your design to better meet the criteria and constraints. You may have to repeat this step several times, or you may have to go back to previous steps and start over. It is all part of the design process – there is no right or wrong way to go through this procedure.Communicate. Document the design process, developing a series of engineering memos and communications with your client at key milestones in the design process, and at the end of the process collecting your results in a Final Report.