We are living in an interconnected world. There is a high need to seek sustainable solutions to environmental challenges (Ho et al., 2017). Vietnam is ranked among the top five countries worst affected by climate change (Bank, 2011). The long coastline, low lying area and complex river systems of the Red River Delta (RRD) (Northern Vietnam) expose it to various consequences of climate change, including erosion, typhoon, sea level rise, flooding, and extreme weather events, etc. [(Le et al., 2014); (Nguyen & Shaw, 2010); (Takagi et al., 2015); (Bank, 2011)]. As a coastal city in the RRD, Haiphong is highly vulnerable to these risks (Give2Asia, 2016).

A previous study by (Le & Ha, 2016) revealed that dealing with disaster risks towards a resilient city is a highly complex issue. This complexity is also reflected in the national strategy for natural disaster prevention, response, and mitigation to 2020 (Government, 2007). Besides building capacity for local organizations, businesses, and communities in response to the uncertain risks, a holistic approach is required to utilize and strengthen public-private partnerships (PPP) for synergic efforts in disaster risk reduction (DRR). In addition, communication strategies through an awareness campaign were also defined as critical to raising awareness of both public and private sectors and thus stronger collaboration in the disaster preparedness and responses (Le & Ha, 2016).

Traditional problem-solving approaches with a top-down and linear vision have been proven inappropriate, leading to various failures and unsustainable outcomes [(Bosch et al., 2014); (Ha et al., 2015); (Ha et al., 2016); (Vester, 2007)]. In terms of project management, the traditional approach using the logframe matrix has recently been criticized due to its rigidity and supply-driven approach where no learning occurs (Fujita, 2010). Acceptance of a soft systems approach in project management and evaluation has been growing. (Pollack, 2007) criticizes the conventional hard paradigm regarding its over-emphasis on control using reductionist techniques in which the project manager is considered as an expert, with no requirement for participation. In contrast, the soft systems approach emphasizes learning and social processes, requiring participation from local beneficiaries and stakeholders.

Systems thinking and system dynamics have recently been proven their effectiveness and validity in addressing complex problems in a variety of contexts around the world [(Bosch et al., 2014); (Bosch et al., 2015); (Maani & Canava, 2007)], including Vietnam [(Ha et al., 2015); (Ha et al., 2016); (Nguyen et al., 2012); (Trinh et al., 2015)]. However, little research has been carried out using the systems thinking approach and system dynamics modeling tools in the field of disaster preparedness.

Therefore, this study was conducted using system dynamics modeling together with a comprehensive communication strategy via a media campaign and partnerships to aim at a resilient and smart city through improved knowledge, awareness, capacity and shared vision among local government organizations, businesses, and community members. In which, local businesses are the primary target group due to a large number of enterprises in the bustling city (Le & Ha, 2016).

The paper describes process steps in configuring the 'big picture' of the current situation in the research area using a systems approach, followed by the identification of strategic actions and/or systemic interventions to achieve the goal, including communication strategies. The conclusion section highlights key findings of this research and recommendations for future research and application.

The study was carried out in Haiphong, a coastal and vulnerable city located in the Red River Delta of northern Vietnam during 2015-2017. A desktop study for understanding the current situation was conducted based on existing information from a previous baseline survey in 2014 (P.W.A., 2014) and secondary data from relevant departments and organizations. Those include the Vietnam Chamber of Commerce and Industry (VCCI) -Haiphong chapter, Haiphong Alliance for Cooperatives and Enterprises, and Departments of Planning and Investment, Statistics, Agriculture and Rural Development, and Natural Resources and Environment, and some active projects of non-profit organizations in the area.

A number of dialogues, focus group discussions, and workshops were organized to obtain inputs from representatives of the local organizations and relevant stakeholders with the support of user-friendly system dynamics modeling tools. Results of these activities together with the desktop studies were used to develop a causal loop diagram and/or a systems model of the project using Vensim^® software (Ventana®, 2011). The model depicted the current situation, highlighting causal relations and patterns of relationships among different factors (key issues identified by the stakeholders) that influence the achievement level of the end goal (disaster ready) Haiphong city. It also revealed leverage points for systemic interventions and which stakeholders could be involved in each inter- vention. NeticaTM software (Norsys, 2013) was used to identify systemic interventions and/or strategic actions and test future scenarios and measure impact through sensitivity analysis and modeling. The sensitivity analysis involved discussions of the participants regarding (1) the current state of each factor (system node and/or variable) within the systems model that were indicated in probability of occurrence; and (2) influence levels of the influencing factors on their dependent nodes, and eventually the target node.

This study has presented the effectiveness of the systems approach, system dynamics modeling tools and communication strategies in coping with complexity in disaster risk management of Haiphong, Vietnam. The approach and tools enabled the research team and participating members to have a better understanding of the current situation. It also showed the interplays among various factors, and areas that require coordinated efforts among the stakeholders for joint planning and execution of the identified systemic interventions to achieve the end goal. Compared to the traditional project management approach, the new approach was proven more time and cost-effective.

In addition, the higher impact would be expected through implementing the nine identified systemic interventions (dark boxes, Figure 2).

Furthermore, diverse forms of communication strategies have been identified and implemented with initial success. The approaches and strategies employed in this study are expected to be adopted in other contexts in dealing with complexity in the changing world of intertwined human and natural factors.

We would like to express our sincere thanks to the local government of Haiphong for their continuous support. Our special thanks go to the Vietnam Chamber of Commerce and Industry (VCCI) – Haiphong chapter, Departments of Agriculture and Rural Development, Planning and Investment, Statistics, and Natural Resources and Environment, Haiphong Alliance for Cooperatives and Enterprises, Haiphong Centre for Environmental Monitoring, and other local business associations and NGOs for their partnerships. We gratefully acknowledge the active participation and contributions of 8 domestic trainers in Haiphong.