The natural system is the starting-point of any Building with Nature project. In order to develop solutions, the general scope and structure of the system need to be defined. To understand the physical, functional and regulatory aspects that are involved, a consistent systems approach is required.The Systems Analysis tool provides guidance to be able to apply this approach within the Building with Nature context, providing the theoretical background behind system analysis. For a more applied description of a system the Ecomindmap or the stakeholder analysis tool can be used. By definition any system analysis deals with elements and relationships between those elements. The action of the whole can only be understood by knowledge of the interactions of all the parts. The work of systems analysis is to select a system or subsystem to be analysed, define its boundary, identify the components and to develop models that describe the interaction of these components. It starts by insisting on a clear understanding of exactly what the problem is and the goal that should dominate the solution and lead to the criteria for evaluating alternative avenues.
The figure shows a typical system diagram for projects in a BwN context (Van der Weide, 1993, Van der Weide and Van Koningsveld, 2003). At the highest level of abstraction, the system is controlled by two main elements: the natural system and the socio-economic system. The former includes all components of the abiotic and biotic environment and the latter includes the users, and the required physical and social infrastructure. The natural subsystem is the field of natural sciences whereas social sciences are required to describe the anthropogenic subsystem. The interactions between the two subsystems and their respective structure and internal processes are depicted in the diagram as well. The interactions between the natural and socio-economic subsystems can be categorised into:
Cross border effects
The systems approach can be applied to different spatial scales. In their books “Limits to Growth” and “Beyond the Limits”, Meadows et al. (1972, 1992) apply a systems approach to the whole world. In practice, however, the system only represents a part of the world. In order to account for the interaction with the environment outside the system, cross border effects have to be included in the system description.
A well-defined system diagram is a useful tool in problem analysis and problem solving. A system analysis for BwN projects should focus on the interaction between various systems. Ecosystem knowledge is especially important for identifying essential supporting services and related natural processes. (e.g. transport, carrying and restoration capacities.) Combining these opportunities that a certain system environment may offer could benefit the project as a whole. Identifying potential win-wins with other projects is another characteristic of a BwN system analysis. Many BwN projects use material that may become available as part of another project. Dredging shipping lanes and harbours generates dredging sludge that may be used for nature restoration purposes or the creation of green defences. Long-term strategies may incorporate a steady stream of dredging sludge, using an incremental development approach. One of the first steps in the EDD-approach is to widen the project scope and make it greener. A proper system analysis in the initiation phase of the project will help to widen the scope. In subsequent project phases the system analysis will still help to identify potential opportunities in combining services and functions.
Setting up a well-defined analysis of the system relevant for the project at hand requires input from a variety of expertise’s. Collaboration between different disciplines should provide with a coherent approach addressing all the key components of a project (natural, social and regulatory). Users of this tool need no special knowledge except their own specific field of expertise.
Phased plan process
Building with Nature designs depend on the environment in which they are planned. Different environments provide different eco-system services, which in turn provide different opportunities for BwN. Systems analysis is a tool to obtain knowledge about the ecosystem in which the BwN project will be developed. This knowledge is necessary to identify:
For BwN the link between environment, project and society is mainly made in terms of ecosystem services. In principle every ecosystem service can act as a target variable for the design and may help to make it more cost-effective, more multifunctional and more acceptable to stakeholders. Systems analysis required for BwN projects identifies the links between ecosystem services. Seasonal dynamics, incidents and trends are especially critical if they have an influence on essential supporting services. Often there is a lack of data, which limits the possibilities to do the necessary analysis. In that case reference studies and data should be used.
An important part of systems analysis is to identify key driving factors, their links to ecosystem processes and services and their capacities. Carrying capacities can be relevant on different system levels. The overall sand balance of the Mississippi Delta will for example determine the long-term sustainability of maintaining the present extension of wetlands and coastlines. Carrying and other capacities of the natural environment are important design variables for a BwN project. It determines limits of what can be done using natural processes. Sometimes a project can become much more cost-effective if its implementation is attuned to natural process capacities. Often, the short-term deadlines require costly engineering interventions. An eco-engineer needs to know the natural process capacities, which include:
Ecosystem services can be divided into four main categories:
The steps mentioned above help to identify impacts and dependencies. The DPSIR tool is an approach that primarily focuses on impacts. But project dependencies are also very important. A project takes place in an environment that is the result of on-going processes and related ecosystem services. An impact analysis focuses on the impact of a project on this environment and vice versa. But there may be other on-going developments that influence the underlying matrix of supporting services. Examples are long-term developments in sand balances, that may be altered due to interventions in adjacent coastal areas or upstream rivers, that block sediment transport. So a comprehensive system analysis goes beyond the mere interaction of the project and its environment, but looks also into overall and general trends.