The Influence of Underlying Stresses from Environmental Hazards on Resilience in Bangladesh: A System View

Abstract: Bangladesh is one of the countries most vulnerable to climate change, while its people also suffer from a range of environmental hazards linked to the growing prevalence of non-communicable diseases. These diseases are responsible for increasing morbidity and mortality and lead to other stresses within the population. Such stresses create continuous impacts on the health and well-being of the population, compounding their vulnerability and inhibiting their capacity to cope with frequent event-related shocks, such as floods and drought. A systems approach is taken to examine four important environmental hazards in Bangladesh—arsenic contamination of drinking water, arsenic transmission through the food chain, indoor air quality, and air pollution. A review of these hazards is presented in a conceptual framework that links human well-being with the key system components of infrastructure, institutions, knowledge, and behavior. This reveals key underlying factors between the hazards and uncovers system structures that can lead to more effective hazard mitigation, and the establishment of strategic intervention points. The article concludes that elimination of these continuous stresses will only come about through the culmination of multiple interventions over time, undertaken in an iterative manner that builds on the continual advancement of hazard understanding. The role of individual behaviors, together with factors such as risk awareness and perception of the hazards, has been identified as crucial for achieving successful mitigation solutions. Improved knowledge of the hazards, public awareness, and government accountability are focus points to reduce population exposure and enhance response capacity

Evaluating the effectiveness of catchment-scale approaches in mitigating urban surface water flooding.

The argument for natural flood management in the UK has strengthened in recent years with increasing awareness of the potential benefits gained from upstream interventions (especially improvements in water quality, public amenities and biodiversity). This study aims to develop an understanding of another potential benefit-interventions promoting free discharge at downstream urban drainage outfalls by moderating water levels in receiving watercourses. A novel, coupled model (linking dynamic TOPMODEL, HEC-RAS and Infoworks ICM) is calibrated for the Asker catchment in Dorset, England. This predominantly rural watershed drains to the town of Bridport, frequently submerging a surface drainage outfall in a nearby housing estate. Two forms of upstream, catchment-scale intervention (hillslope tree planting and in-channel large woody debris) are modelled to understand their impacts on the functioning of the drainage network during both the calibration period and a range of design storms. The results indicate that interventions have the greatest positive impact during frequent events. For example, during a storm with a 10% annual exceedance probability (AEP), upstream NFM could reduce outfall inundation by up to 3.75 h and remove any surcharging of flow within the drainage system in Bridport. In more severe storms, the results suggest interventions could slightly prolong the time the outfall was submerged. However, by slowing the wider catchment's response during the 3.3% AEP storm, upstream interventions allow more water to escape the urban drainage system and reduce the maximum surface flooding extent within the housing estate by 35%. This article is part of the theme issue 'Urban flood resilience'.EPSRC for funding this research through the EPSRC Centre for Doctoral Training in Future Infrastructure and Built Environment (EPSRC grant reference number EP/L016095/1) and Urban Flood Resilience (EPSRC grant reference number EP/P004180/1)

Integrating blue-green and grey infrastructure through an adaptation pathways approach to surface water flooding.

A range of solutions to future flood risk are available ranging from blue-green infrastructure (BGI) as commonly incorporated in sustainable drainage systems (SuDS) to traditional grey infrastructure (e.g. pipe networks, storage tanks, flood walls). Each offers a different profile with respect to costs, flexibility of implementation and the ability to deliver a range of wider benefits beyond their flood protection function. An important question that must be addressed when considering these approaches is what is the most suitable mix of grey and blue-green solutions to urban flooding at any location and at any future time? This paper uses an adaptation pathways approach to compare a range of alternative options to deal with current and expected future flood risk in part of a London borough. Solutions considered separately and in combination include grey pipe expansion, bioretention cells, permeable pavements and storage ponds. A methodological framework combines a range of existing tools to develop, assess and characterize each pathway, including a storm water management model (SWMM), a SuDs opportunity selection tool, an adaptation pathway generator and the CIRIA B£ST tool for monetizing multiple benefits. Climate change is represented by the UK Water Industry Research method for establishing future rainfall intensities for sewer and BGI design. The results showed that by extending the way in which adaptation pathways are compared and evaluated through the wider consideration of multiple benefits there is a trade-off between deferring interventions until they are needed for flood risk mitigation and delivering the multiple benefits associated with interventions so that performance thresholds do not need to be met before introducing new options. The relative contribution of each option's capital and operation and maintenance costs has implications on when the option is implemented as well as the rate of implementation. The monetization of the multiple benefits associated with each pathway shows that their economic co-evaluation alongside infrastructure costs can change the preference for one pathway over another. This article is part of the theme issue 'Urban flood resilience'.EPSR

Characterizing the dissemination process of household water treatment systems in less developed countries

Recently, household-level water treatment and safe storage systems (HWTS) have been developed and promoted as simple, local, user-friendly, and low cost alternatives to conventional municipal-level drinking water treatment systems. Yet, despite conclusive evidence of the health and economic benefits of HWTS, the implementation outcomes have been slow, reaching only approximately 5-10 million people. This study attempts to understand the barriers and drivers affecting HWTS implementation. A review of existing literature on HWTS implementation found that existing research effort to promote HWTS is rather fragmented, with a narrow focus either on technical, psychological, or marketing perspective. Also, the application of innovation diffusion theories on HWTS implementation has been largely unexplored. To fill these research gaps, it is proposed that a system dynamics modelling approach to characterize the complex diffusion process of HWTS can be a valuable tool to identify high impact, leverage strategies to scale-up HWTS adoption and sustained use

Engineers as advocates for sustainable development: Countering misinformation and the need for Aristotelian rhetoric

The paper argues that engineers need to take action as advocates for sustainable development, and for spotting and correcting fake news and mis-information. The spread of counter factual information is reviewed and its impact on encouraging denial of globally important issues, such as climate change is highlighted. Strategies for responding and correcting misinformation are presented and the importance of understanding and engaging in persuasive arguments through the application of the ethos, logos and ethos of Aristotelian rhetoric is explored. The paper presents examples of classroom exercises where these concepts are considered and developed with engineering graduate students and concludes by calling for such students to develop a voice as advocates for sustainable development

Spatial Analysis of the Drivers, Characteristics, and Effects of Forest Fragmentation

Building on the existing literature, this study examines whether specific drivers of forest fragmentation cause particular fragmentation characteristics, and how these characteristics can be linked to their effects on forest-dwelling species. This research uses Landsat remote imaging to examine the changing patterns of forests. It focuses on areas which have undergone a high level of a specific fragmentation driver, in particular either agricultural expansion or commodity-driven deforestation. Seven municipalities in the states of Rondônia and Mato Grosso in Brazil are selected as case study areas, as these states experienced a high level of commodity-driven deforestation and agricultural expansion respectively. Land cover maps of each municipality are created using the Geographical Information System software ArcGIS Spatial Analyst extension. The resulting categorical maps are input into Fragstats fragmentation software to calculate quantifiable fragmentation metrics for each municipality. To determine the effects that these characteristics are likely to cause, this study uses a literature review to determine how species traits affect their responses to forest fragmentation. Results indicate that, in areas that underwent agricultural expansion, the remaining forest patches became more complex in shape with longer edges and lost a large amount of core area. This negatively affects species which are either highly dispersive or specialist to core forest habitat. In areas that underwent commodity-driven deforestation, it was more likely that forest patches would become less aggregated and create disjunct core areas. This negatively affects smaller, sedentary animals which do not naturally travel long distances. This study is significant in that it links individual fragmentation drivers to their landscape characteristics, and in turn uses these to predict effects on species with particular traits. This information will prove useful for forest managers, particularly in the case study municipalities examined in this study, in deciding which species require further protection measures. The methodology could be applied to other drivers of forest fragmentation such as forest fires

Spatial evaluation of the multiple benefits of sustainable drainage systems

Traditional approaches to understanding the multiple benefits of sustainable drainage systems often rely on value transfer. This converts each benefit into a monetary value, which can then be compared with the cost of the project. The approach, while well-developed, is limited because it does not systematically incorporate the spatial nature of the benefits. This paper discusses the development of an alternative way of evaluating and comparing benefits, allowing spatial distribution and local context and circumstances to be taken into consideration. The suggested approach is to create a score for each benefit category, which is normalised against a defined initial condition state on a scale of 0 to 10. This approach allows a direct comparison of the relative magnitude of benefits for a given location and provides a clear understanding of how and to whom multiple benefits accrue. The approach allows a singular significant benefit to be compared against many minor benefits. It can also easily be modified to reflect local preferences by weighting each benefit category appropriately. The method is demonstrated by three case studies in Newcastle, UK.This research was performed as part of an interdisciplinary project programme undertaken by the Blue-Green Cities (BGC) Research Consortium (www.bluegreencities.ac.uk) The BGC Consortium is funded by the UK Engineering and Physical Sciences Research Council under grant EP/K01366 1/1, with additional contributions from the Environment Agency and Rivers Agency (Northern Ireland) and National Science Foundatio

A stochastic model for the evolution of the Web

Recently several authors have proposed stochastic models of the growth of the Web graph that give rise to power-law distributions. These models are based on the notion of preferential attachment leading to the "rich get richer" phenomenon. However, these models fail to explain several distributions arising from empirical results, due to the fact that the predicted exponent is not consistent with the data. To address this problem, we extend the evolutionary model of the Web graph by including a non-preferential component, and we view the stochastic process in terms of an urn transfer model. By making this extension, we can now explain a wider variety of empirically discovered power-law distributions provided the exponent is greater than two. These include: the distribution of incoming links, the distribution of outgoing links, the distribution of pages in a Web site and the distribution of visitors to a Web site. A by-product of our results is a formal proof of the convergence of the standard stochastic model (first proposed by Simon)

The Barcelona Declaration revisited: core themes and new challenges

The 2004 Barcelona Declaration is briefly reviewed and gaps reflecting sustainability are identified. We ask is the Barcelona Declaration still fit for purpose, and what can be added or amended to reflect new trends and challenges that should be the over-riding concern of all responsible engineers? Our aim is to stimulate a debate so that EESD 20 can collectively agree to update a new version of the Declaration which reflects with urgency the growing emergency we face. We identify 9 dimensions which are not explicitly reflected in the original Declaration and propose 6 new competences which might be added to reflect how the drivers behind engineering education for sustainable development must reflect an understanding of six imperatives: values, context, uncertainty, change, limits and vision