A Systems Approach to Modeling the Water-Energy-Land-Food Nexus, Volume II

System Dynamics Modeling and Dynamic Scenario Planning

Bernard Amadei

• Publisher: Momentum Press
• Year: 2019
• ISBN:
  9781947083554
• Topic: Architecture
• Subtopic: Sustainability in Architecture

This two-volume book describes a flexible and adaptive system-based methodology and associated guidelines for the management and allocation of community-based WELF resources.

Over the next 50 years, rapid population, urbanization, and economic growth worldwide will create unprecedented demands for water, energy, land, and food (WELF) resources. The discussion on how to meet human needs for WELF resources and how to guarantee their respective securities has changed over time from looking at all four sectors in isolation to understanding their interdependency through the so-called WELF nexus.

The approach presented in this book responds to the overall agreement in the WELF nexus literature that the management and allocation of WELF resources at the community level need to be examined in a more systemic, multidisciplinary, participatory, and practical manner while seeking to increase synergies and reduce trade-offs. This book was written to explore the value proposition of that approach. This two-volume book describes a flexible and adaptive system-based methodology and associated guidelines for the management and allocation of community-based WELF resources.

Volume 1 focuses on defining the landscape in which the nexus operates and outlines the proposed methodology. Volume 2 explores the quantitative and qualitative modeling of the nexus and landscape using system modeling tools including system dynamics. It presents a road map for the formulation, simulation, selection, and ranking of possible intervention plans. The proposed methodology is designed to serve as a guide for different groups involved in the science and policy decision aspects of the WELF nexus within the context of community development. The methodology focuses mostly on WELF-related issues in small-scale and low-income communities where securing resources is critical to their short- and long-term livelihood and development.

CHAPTER 5

A System Dynamics Approach to the Nexus

This chapter reviews first different soft and hard system-based formulations that have been proposed in the literature to model the interaction between several components of the FEW/WELF nexus. It then presents a value proposition for using qualitative and quantitative system ­dynamics simulation models to capture the dynamics at play across the nexus, including interactions across the nexus components and their interactions with social, natural, infrastructure, and economic systems. The chapter presents the characteristics of systems thinking and reviews basic system dynamics tools, systems archetypes, and the different steps involved in the system dynamics modeling methodology. As a hard systems approach, system dynamics has unique characteristics that warrant its use when ­simulating how the different sectors of the nexus unfold and interact when subjected to different inputs and constraints. In turn, the simulations help decision makers to make management decisions and select interventions across the nexus and at the community level. The chapter concludes with a discussion of the value added by using social network analysis and the importance of engaging in participatory modeling to develop system dynamics models.

God grant me the serenity to deal with ill-defined and messy systems over which I have little or no control, courage to improve systems over which I have some control, and wisdom to know the difference.

—adapted from the Serenity Prayer, R. Niebuhr

5.1 Introduction

Volume 1 emphasized the value proposition that the landscape in which the FEW/WELF nexus unfolds and community development takes place is a complex and adaptive landscape and argued that it should be ­handled as such when managing and allocating water, energy, land, and food resources. The landscape consists of multiple complex, ­complicated, or simple systems and subsystems, with each providing functions and ­purposes with different degrees of intra- and inter-connectivity. This global picture suggests that adopting a systems mindset, rather than a deterministic sectorial mindset, is better for appraising the landscape and formulating dynamic hypotheses around critical issues that are at play in the landscape. It also implies that the management and allocation of FEW/WELF resources within the overall context of community development must be conducted with an integrated (e.g., systemic) and participatory perspective by considering the following dynamics: (i) the water, energy, and food sectors and their supply chains (from acquisition, to production and processing, to consumption, and ultimately to waste disposal), including their dependencies; (ii) the links between these sectors and land; and (iii) how the nexus as a whole interacts with human/social, natural, infrastructure, and economic systems.

It should be noted that the FEW/WELF literature has mostly emphasized why an integrated or systems approach should be used to understand the nexus dynamics (Alcamo 2015; McCormick and Kapustka 2016; Wolfe et al. 2016; among others). This, in turn, has helped decision and policymakers to become aware that: (i) synergies and trade-offs between sectors of the nexus need to be considered in the management and allocation of water, energy, land, and food resources, and (ii) decisions at one spatial or temporal scale may impact decisions at other scales. Finally, it has become clear that the FEW/WELF nexus cannot be separated and analyzed independently from the landscape in which it unfolds.

Compared to the “why,” the “what” and especially the “how” of the integrated perspective of the FEW/WELF nexus is still a work in progress in the literature where different versions of both soft and hard systems approaches have been advocated. As noted by Checkland and Poulter (2006), both approaches have different characteristics. A soft systems approach to a problem focuses more on the “systemic” process of inquiry and “problem situations,” but not on the structure of the problems per se. On the other hand, a hard systems approach includes the development of systems models (qualitative and quantitative) to address both the systemic and structural aspects of the problem being analyzed.

The soft systems approach to the nexus has been formulated and presented in many different forms. Graphical representations such as those shown in Figures 1.1 and 1.2 (and multiple variations of it) abound and have been proposed, for instance, to capture the two- or three-way ­interactions between water, energy, and food and how these sectors ­interact with other factors such as land, climate, the environment, or waste (WBCSD 2009; Bazilian et al. 2011; Hoff 2011; FAO 2014; Wakeford et al. 2015; Sohofi et al. 2016; among others). Double entry matrixes have also been proposed to show links between the different sectors of the nexus and their indicators (Flammini et al. 2014; Ferroukhi et al. 2015; Wakeford et al. 2015; among others). In Chapter 3, a soft approach was used, for instance, to emphasize the types of impacts that exist across the nexus components (Table 3.5). In Chapter 4, the emphasis was on mapping the impacts that exist among the four system groups at play in the landscape (Table 4.2).

A soft systems approach is clearly a step toward considering all sectors of the nexus in isolation. However, it stops short of being able to quantitatively model the dynamics and structure of the nexus in depth and how its sectors interact with the landscape and its systems. This could be handled better using a hard systems approach with system dynamics modeling tools, as discussed in Volume 2 of this book.

5.2 Hard Systems Approaches to the Nexus

Various hard system-based formulations have been proposed in the literature to model the combined systemic and structural aspects of the interactions among components of the FEW/WELF nexus. They fall over a spectrum that ranges from global to sector-specific formulations. Among all existing hard systems formulations, those that use the system dynamics modeling methodology (discussed further in this chapter) seem to offer the most value in modeling the management and allocation of FEW/WELF resources over time.

5.2.1 Global Formulations

Since 2011, the development of hard system models of the complex and adaptive landscape in which the FEW/WELF nexus unfolds and ­community development takes place has happened in parallel to formulations used in the closely related field of international development and aid. With some modifications, both approaches could be combined to ­integrate systems thinking into nexus studies and in the context of community development.

As described, for instance, in the book A Systems Approach to Modelling Community Development Projects (Amadei 2015), there has been a strong interest in the global development literature in adopting a systems perspective to account for the interactions of socioeconomic-political and technical issues. The book, Aid on the Edge of Chaos, by Ramalingam (2014) provides an excellent introduction to the scientific study of complex systems and reviews a wide range of applications of systems thinking in global development and aid-related topics.

Ramalingam’s book builds on several other authors’ observations that in development and aid, complexity and systemic behavior are the norm and not the exception and therefore should be embraced instead of ignored (Rihani and Geyer 2001; Rihani 2002; Mavotras 2010; Porter 2011; ­Breslin 2004; Neely 2015; Wu 2016). Despite international development and aid’s slow progress toward incorporating systems thinking and the science of complexity, some studies over the past 10 years have clearly demonstrated the benefits of using systems thinking and systems modeling, primarily when making decisions and developing systemic policy solutions at the regional or country scale (Reynolds et al. 2003; Hjorth and Bagheri 2006; Scoones et al. 2007; Newell et al. 2011; USAID 2011a,b; 2014; Williams and Britt 2014; Fowler and Dunn 2014; Neely 2015; Downes and Bishop 2016; among others).

The methodologies associated with the studies mentioned above, however, have a limited range of applications if they were to be used for making decisions and proposing solutions in the management and allocation of FEW/WELF resources. First, they are not designed for ­making decisions and proposing solutions at the community scale, which is the scale of inte...

Table of contents

• Cover
• halftitle
• title
• copyright
• abstract
• contents
• List of Figure
• List of tables
• Preface
• 05_Chapter 5
• 06_Chapter 6
• 07_Chapter 7
• 08_Chapter 8
• 09_Appendix A
• 10_Appendix B
• 11_Bios
• 12_Index
• 13_Adpage
• backcover