Environmental Risk: River Flood in Bangladesh - Case Study Example

ENVIROMENTAL RISK: Science, Policy, and Management RIVER FLOOD IN BANGLADESH 1. Justification for selecting this particular environmental issue Selection of this particular environmental risk issue was primarily influenced by its relevance to the requirements of this report. River flooding in Bangladesh is caused by environmental risk, local-level, and in a specific geographical location. More importantly, Bangladesh is a country noted for its vulnerability to environmental risks. According to the report presented by Gaan & Daas (2004, p.222), Bangladesh is prone to natural disasters particularly floods, cyclone, storms and surges. In addition, sea level rise due to global warming has added to the risk of these distressing natural disasters. Bangladesh occupies about 145,000 square kilometer where 80 percent are flood plains. However, not only the floodplains are subject to floods as interior terrace areas, hills, and valleys are affected. The floodplains are affected by different types of flooding such as prolonged heavy rainfall which had resulted to the devastating 1987 and 1988 flood. Moreover, the depth and duration of flooding varies depending on the amount on the amount floodwater entering the country and the river flows on its major rivers (Parker 2000, p.104). 2. Logic Tree A logic tree is a tool that uses cause-and-effect concept that can be use instead of flowchart. A ‘why-why diagram’ (Okes 2009, p.51), a logic tree concept is a simplified form of fault-tree analysis which looks at the different ways a system can fail. Logic trees can break a particular system down in different ways. It can be component focused, failure mode focused, and process focused (Okes 2009, p.52). The purpose of logic trees is to identify hazard sources accurately and to help analyst and practitioners track all likely pathways through which targets may be affected. Two methods in creating a logic tree will be adopted to identify risks, pathways, and the possible consequences in terms of losses to population and other inhabitants of Bangladesh River flooding. Fault Analysis 3. Scientific Approaches Evaluation of logic trees such as the fault trees presented earlier may include qualitative or quantitative evaluation. Qualitative evaluation requires determination of the logic trees cut sets, path sets, or logical evaluation to be able to arrange the tree logic for computational efficiency. For this reason, identifying the logic tree cut sets may include direct Boolean manipulation of events. The qualitative evaluation of logic trees done this way would produce a tree OR –gate the represents the union of the input events. In other words, any input events must occur to cause the output event to occur (Modarres 2006, p.54). The Boolean Algebra Analysis of Logic Trees may be presented by: Let A and B as input events and Q as the output event thus; Q = A ∪ B This means that the occurrence of either A, B, or both must occur in order for Q to occur. The Boolean logic and algebra help represent and quantify the interactions between events. The primary Boolean operators are AND and OR gates. With an AND gate, the output of the gate, the event that is at the top of the symbol, occurs only if all of the conditions below the gate and feeding into the gate coexist. With the OR gate, the output event occurs if any one of the input events occur (Maynard & Zandin 2001, p.198). 4. Weaknesses of the currently available scientific knowledge Although it can be seen that fault tree analysis approach is particularly helpful in some areas such as highlighting the weaknesses of a system, identifying failure modes deductively, and more, fault trees are not free from problems and limitations. For instance, fault tress does not show sequence of events. The use of binary logic approach seems limited since only two states can be presented. Moreover, time and rate dependence cannot be represented conveniently (Rasbash et al. p.398). Since humans are not perfect and subject to misperception or miscalculations, recognition of the limitations of quantitative approach is essential as its validity depends upon the accuracy of the basic human error estimates. Although the result of quantitative assessment can be particularly useful on a comparative basis, the absolute accuracy of results should use carefully (Kirwan & Ainsworth 1992, p.192). In other words, the usefulness of this approach depends on the accuracy of the input thus accuracy human evaluation of the risk is very important. For instance, inputs must come from a comprehensive study to ensure that all factors or elements contributing to fault are covered. Moreover, these factors should be arranged by priority or possibility of occurring to avoid misinterpretation during the fault analysis. 5. Assessment of the Feasibility of Controlling the Risk In studying river floods in Bangladesh, it has been found that there are indeed some existing forms of flood mitigation strategies. Embankments were used but there are indications that structural flood protection had not lessened overall losses or even threats to life in case of a more extreme events. Problems found in the embankment projects include breaches of embankments to reduce water logging inside or outside the embankment. According to Parker (2000, p.316), the shortcomings of embankments are not only failures to achieve intended benefits, but also unintended economic, social, and environmental impacts. A few of the reasons of failure was the lack of regular maintenance and damages due to the intentional overtopping of the embankments. Many of the embankments have unplanned uses particularly as roads, growing trees, temporary shelters during flood, and for people displaced by erosion. These uses are important unintended benefits from the projects and tend to be ignoring in planning but cause maintenance problems, particularly when housing damages embankment slopes. More importantly, there is no framework for legitimizing these uses and at the same time regulating them. Therefore, there is no way to prevent damage, or to oblige users to maintain embankments so that they perform the primary function. Another problem with embankments, Parker (2000, p.323) explained, is the reduction of basic habitat for fish. This is because embankments and water control structures built across natural channels obstruct breeding and feeding migrations of fish between rivers and the remaining floodplain wetlands. Obstruction of fish and prawn movements has inhibited and disrupted their reproduction and sustenance. Closures also change the flow pattern and the characteristics of rivers, which in places turn static from flowing water. Consequently, species composition and species diversity have been altered. In other words, most embankment projects had negative impact on fisheries. The average catch per person was reported to decline by 60 percent thus anglers left their occupation or were forced to move to the main rivers for fishing resulting to overfishing. On other impacts, although embankments have been successful in protecting crops, there are many cases that embankments were found to be ineffective in protecting property and crops in severe floods. Overall, problems with embankments, which are commonly viewed as being technical, and maintenance related appears to be more associated with the inadequacies of institutional framework and in technical, environmental or social planning of projects. More importantly, there is no cross-border coordination with the upper bordering country resulting to drainage congestion. Improving embankment performance may be possible through proper planning and participation since most of the flood control projects were seen as economically viable and can be more effective if maintained. Consequently, the most feasible solution is to improve operation, maintenance, and rehabilitation of existing projects including enhanced management. It is also important to give more emphasis on using environmental impact assessment and mitigation. For this reason, the work of various agencies must be coordinated and integrated towards a common objective in order to achieve sustainable economic development particularly in the flood plains. Finally, all projects implemented must maintained regularly by local agencies’ resources instead of depending on the external assistance. 6. Comparison to other Environmental Risk Flood in itself is a specific environmental risk and the virtual unpredictability of severe flooding posed huge financial losses (Zagaski 1991, p.190). In terms of environmental impact, assessment may be made by understanding the significance of impact. Permanent or frequent flooding may lead to destruction of habitat and permanent loss of valuable geological features (Morris 2008, p.398). Unlike, earthquake which detection of event are more sophisticated (Lindell & Perry, 2004, p.10) than noticing the water rising, the occurrence flood particularly in Bangladesh is obvious and needs no sophisticated detection mechanism. Flooding in Bangladesh, as mentioned earlier, occurs frequently and more often affect the population negatively. Moreover, flooding in Bangladesh is not caused by a single source but multiple sources such rivers flowing from outside the country, storm surges, excessive rainfall, and tropical cyclones. More importantly, a large of area is flood plains, which means it is more likely to have more environmental risk. The environmental risk in Bangladesh apparently is an inherent problem caused by its geographical location and if there are mitigations being done to reduce the problem, there is no strong institutional framework to support it. More importantly, flood controls are not properly maintained and helpless against extreme flooding. 7. Evaluation of People’s Perception of the Selected Environmental Risk There evidence in literatures that success of disaster warnings are correlated with the people’s threat beliefs, hazard knowledge, risk perception, and warning compliance (Lindell & Perry 2004, p.148). This is because the notion of risk has various meanings to people and physiologically, the definition of risk is too narrow for humans. Humans tend to view risk as more of an event that is associated with danger, fear or harm which is socially constructed by norms, media, and other factors (Casimir 2008, p.62). According to Wilson (1991, p.81), the primary factors in the perception of risk is control and the ability to understand thus people are more often underestimate the risks when they feel that they are in change and can make decisions on whether or not to take the risks and how the risk factors will be dealt with. Moreover, the ability to understand the risks implies that risks from sources perceived as unknown, unseen, or unfamiliar are more likely to generate negative reactions. In Bangladesh, the result of one major study conducted by Zschau & Kuppers (2003, p.21) when a major cyclone struck the country in 1991, found that 95 percent of the households surveyed were aware of the risk but almost half of them do not believe that the consequences would be severe. Others simply do not understand the risk at 16 percent and 70 percent of those who do not want to relocate believe that the risk would actually do them harm. In Nepal, although there was significant indication the natural dam holding back the Tsho Rolpa glacial lake could burst at any time during the imminent monsoon season that would cause significant flooding, a lot of residents do not know what to do or where to go. Some people were more cautious and evacuated while others cannot leave because they do want to abandon their land. Moreover, villagers near the valley refused to heed the warning and told the officials they were speaking nonsense. These villages trusted their own observations, which were based on many years of experience and belief that their Gods are protecting the valley. In Western countries, people believed in their rights to live and work in environments deemed to be hazardous and some even think that risk-taking is natural in a free society. According to Smith (1992, p.47), floodplain dwellers tend to buy homes in cheaper locations than is safer area of town. In addition, even those that suffered large losses from flooding did not seem inclined to remedy their situation (Gerard et al. 2001, p.355). In general, risk is a relative depends on the vulnerability of a social group and its perception of the hazard. The level of risk seems to require establishment of physical values of every hazard involved and the knowledge of the phenomenon (Koster 2005, p.355). 8. References Casimir M. 2008. Culture and the changing environment: uncertainty, cognition and risk management in cross-cultural perspective. Berghahn Books, US Gaan N. & Das S. 2004, Recrudescence of violence in Indian North-east states: roots in environmental scarcity, induced migration from Bangladesh. Gyan Publishing House, India Gerrard S., Turner K., & Bateman I. 2001. Environmental risk planning and management. Edward Elgar Publishing, UK Kirwan B. & Ainsworth L. 1992. A Guide to task analysis. CRC Press, UK Koster E. 2005. The physical geography of Western Europe. Oxford University Press, UK Lindell M. & Perry R. 2004. Communicating environmental risk in multiethnic communities. SAGE, US Maynard H., & Zandin K. 2001. Maynard's industrial engineering handbook. McGraw-Hill Professional, US Modarres M. 2006. Risk analysis in engineering: techniques, tools, and trends. CRC Press, US Morris P. 2008. Methods of Environmental Impact. Taylor & Francis, UK Rasbash D., Ramachandran G, & Kandola B. 2004. Evaluation of fire safety. John Wiley and Sons, UK Okes D. 2009. Root Cause Analysis: The Core of Problem Solving and Corrective Action. American Society for Quality, US Parker D. J. 2000. Floods, Volume 1. , Taylor & Francis, US Smith K. 1992. Environmental hazards: assessing risk and reducing disaster. Routledge, UK Wilson A. 1991. Environmental risk: identification and management. CRC Press, US Zagaski C. 1991. Environmental risk and insurance. CRC Press, US Zschau J. & Kuppers A. 2003. Early warning systems for natural disaster reduction. Springer, US Read More