Coping with riverbank erosion hazard and displacement in bangladesh: survival strategies and adjustments

As a deltaic plain, Bangladesh annually experiences riverbank erosion hazard due to sudden and rapid channel shifting, particularly in the major floodplain areas of the country. Consequently, valuable cultivable land is lost; also village settlements, markets and towns are destroyed, displacing tens of thousands of people. This paper examines the magnitude of river channel migration and encroachment on land, and the nature of human adjustment systems in the Brahmaputra–Jamuna floodplain, by investigating aspects of the social and cultural dynamics of resettlement of the displaced people. Some policy measures are recommended to improve the ability of the people in the floodplain to cope with these hazards.     

A simple model for complex waste recycling scenarios in developing economies

Future uncertainties involved in the current waste management activities in the developing nations have been addressed through determining plastic waste recovery, recycling and landfilling scenarios in two case study countries — Bangladesh and India. In order to discern and comprehend the material in-flow and out-flow of such complex successive plastics recoveries and recyclings, within the closed-loop recycling systems present in these two countries, a simple mathematical model is developed. The model is based on limited published information, on extensive fieldwork in Dhaka, Calcutta and Delhi, and on experimental data. An environmental legislative factor has been included in the model which will allow balancing of the quality of recycled products and the amount of landfilling non-recyclable plastics. The model has the potential to create and predict a sound waste database for these countries. Bangladesh has been chosen as a model developing country for this study. The mathematical model can be used in future decision making processes within the plastics recycling arena of the countries concerned to achieve an environmentally sound and cost effective waste management option.     

Screening the phytoremediation potential of desert broom (Baccharis sarothroides Gray) growing on mine tailings in Arizona, USA

The metal concentrations in a copper mine tailings and desert broom (Baccharis sarothroides Gray) plants were investigated. The metal concentrations in plants, soil cover, and tailings were determined using ICP-OES. The concentration of copper, lead, molybdenum, chromium, zinc, arsenic, nickel, and cobalt in tailings was 526.4, 207.4, 89.1, 84.5, 51.7, 49.6, 39.7, and 35.6mgkg(-1), respectively. The concentration of all elements in soil cover was 10-15% higher than that of the tailings, except for molybdenum. The concentration of copper, lead, molybdenum, chromium, zinc, arsenic, nickel, and cobalt in roots was 818.3, 151.9, 73.9, 57.1, 40.1, 44.6, 96.8, and 26.7mgkg(-1) and 1214.1, 107.3, 105.8, 105.5, 55.2, 36.9, 30.9, and 10.9mgkg(-1) for shoots, respectively. Considering the translocation factor, enrichment coefficient, and the accumulation factor, desert broom could be a potential hyperaccumulator of Cu, Pb, Cr, Zn, As, and Ni.     

The effects of daily cover soils on shear strength of municipal solid waste in bioreactor landfills

Bioreactor landfills are operated to enhance refuse decomposition, gas production, and waste stabilization. The major aspect of bioreactor landfill operation is the recirculation of collected leachate back through the refuse mass. Due to the accelerated decomposition and settlement of solid waste, bioreactor landfills are gaining popularity as an alternative to the conventional landfill. The addition or recirculation of leachate to accelerate the waste decomposition changes the geotechnical characteristics of waste mass. The daily cover soils, usually up to 20–30% of total MSW volumes in the landfill, may also influence the decomposition and shear strength behavior of MSW. The objective of this paper is to study the effects of daily covers soils on the shear strength properties of municipal solid waste (MSW) in bioreactor landfills with time and decomposition. Two sets of laboratory-scale bioreactor landfills were simulated in a laboratory, and samples were prepared to represent different phases of decomposition. The state of decomposition was quantified by methane yield, pH, and volatile organic content (VOC). Due to decomposition, the matrix structure of the degradable solid waste component was broken down and contributed to a significant decrease in the reinforcing effect of MSW. However, the daily cover soil, a non-degradable constituent of MSW, remains constant. Therefore, the interaction between daily cover soil particles and MSW particles will affect shear strength behavior. A number of triaxial tests were performed to evaluate the shear strength of MSW. The test results indicated that the shear strength of MSW was affected by the presence of cover soils. The friction angle of MSW with the presence of cover soil is higher than the friction angle of MSW without any cover soils. The friction angle of MSW increased from 27° to 30° due to the presence of cover soils for Phase 1 samples. The increased strength was attributed to the friction nature of sandy soil that was used as daily covers soils. Therefore, the effects of cover soils on the shear strength properties of MSW should be evaluated and taken into consideration during stability analyses and design.     

Human vulnerability, dislocation and resettlement: adaptation processes of river-bank erosion-induced displacees in Bangladesh

The purpose of this research was to identify and analyse patterns of economic and social adaptation among river-bank erosion-induced displacees in Bangladesh. It was hypothesised that the role of social demographic and socio-economic variables in determining the coping ability and recovery of the river-bank erosion-induced displacees is quite significant. The findings of the research reveal that displacees experience substantial socio-economic impoverishment and marginalisation as a consequence of involuntary migration. This in part is a socially constructed process, reflecting inequitable access to land and other resources. Vulnerability to disasters is further heightened by a number of identifiable social and demographic factors including gender, education and age, although extreme poverty and marginalisation create complexity to isolate the relative influence of these variables. The need to integrate hazard analysis and mitigation with the broader economic and social context is discussed. It is argued that the capacity of people to respond to environmental threats is a function of not only the physical forces which affect them, but also of underlying economic and social relationships which increase human vulnerability to risk. Hazard analysis and mitigation can be more effective when it takes into account such social and demographic and socio-economic dimensions of disasters.     

Vigilance monitoring for operator safety: A simulation study on highway driving

INTRODUCTION: Alertness of individuals operating vehicles, aircrafts, and machinery is a pre-requisite for safety of the individual and for avoiding economic losses. In this paper, we present a new technique for determining the alertness level of the operator and elaborate the methodology for the specific case of highway driving METHOD: Our hypothesis is that the time derivative of force exerted by the driver at the vehicle-human interfaces can be used to construct a signature of individual driving styles and to discern different levels of alertness RESULTS: In this study, we present experimental results corroborating this hypothesis and introduce a parameter, 'spikiness index,' for the time series data of the force derivative to quantify driver alertness IMPACT ON INDUSTRY: The low cost, ruggedness, and low-volume data processing requirements of the proposed technique give it a competitive edge over existing predominantly image processing based vigilance monitoring systems.     

Energy and greenhouse gas impacts of mining and mineral processing operations

Life cycle assessments of the mining and mineral processing of iron ore, bauxite and copper concentrate were carried out, focussing on embodied energy and greenhouse gas emissions. The results showed that loading and hauling make the largest contributions to the total greenhouse gas emissions for the mining and processing of iron ore and bauxite. In the case of copper ore, the crushing and grinding steps make the largest contribution to the total greenhouse gas emissions for the production of copper concentrate. These results indicate that efforts to reduce the increased greenhouse gas emissions from mining and mineral processing, anticipated in the future as a result of falling ore grades and more finer-grained deposits, should focus on loading and hauling for iron ore and bauxite, while for copper ore the focus should be on grinding. There are a number of new and emerging technologies that could be expected to assist in this task, and these include high pressure grinding rolls and stirred mills for grinding, and further advances in diesel engine technology for loading and hauling applications.     

Scenario of solid waste reuse in Khulna city of Bangladesh

The reuse and recycling of waste materials are now sincerely considered to be an integral part of solid waste management in many parts of the world. In this context, a vast number of options ranging from small scale decentralized to larger scale centralized plants have been adopted. This study aimed at investigating the waste reuse schemes in Khulna city located in the southern part of Bangladesh and ranked third largest city in the country. The shops for reusable material (SRM) were mostly situated around railway, waterway, and truck station markets which provided easy transportation to further locations. For the reuses of waste materials and products, a chain system was found to collect reusable wastes under a total number of 310 identified SRM with 859 persons directly or indirectly involved in the scheme. This was a decentralized waste management system with self sufficient (autonomous) management. According to mass balance, about 38.52 tons d^?1 solid wastes were reused in Khulna city area, accounting for 7.65% of the total generated wastes. This study revealed that apparently a silent, systematic, smooth, and clean reuse chain has been established in Khulna city area under private initiatives, whose sustainability was confirmed over the years in the country without any official or formal funds. However, proper adjustment between the higher and lower chain in the materials flow path, as well as personal hygiene training for the workers, would further improve the achievements of the established reuse scheme.     

An AHP-ELECTRE framework to evaluate barriers to green supply chain management in the leather industry

ABSTRACT

The leather-processing industry (LPI) is constantly polluting the environment in Bangladesh. As a result, stakeholders are continuously pressurizing managers working in LPI to embrace green leather-processing activities. Thus, the green concept is attracting significant attention from managers in the Bangladeshi LPI. However, the industry is struggling with many barriers to implementing green supply chain management (GSCM). There are many studies regarding barriers to GSCM. However, those studies failed to show the possible pathways to implement GSCM. This study addresses the gap by evaluating barriers to GSCM considering effective pathways to GSCM. In this study, the Analytical Hierarchy Process (AHP) is integrated with Elimination Et Choix Traduisant La Realite (ELECTRE-I) method to identify and prioritize the barriers and to rank the possible pathways to implementing GSCM in the leather industry. To accredit the proposed framework, it is implemented on a leather-processing factory in Bangladesh. A sensitivity analysis is performed to inspect the strength of the outcome of this method. The outcome of this study indicates that the high cost of advanced technology is the most important barrier to implement GSCM while green technology and techniques are the most effective pathways to GSCM. The findings of this research will support researchers and practitioners by giving insights on barriers and possible pathways to implementing GSCM.     

What are the implications of sea-level rise for a 1.5, 2 and 3 °C rise in global mean temperatures in the Ganges-Brahmaputra-Meghna and other vulnerable deltas?

Even if climate change mitigation is successful, sea levels will keep rising. With subsidence, relative sea-level rise represents a long-term threat to low-lying deltas. A large part of coastal Bangladesh was analysed using the Delta Dynamic Integrated Emulator Model to determine changes in flood depth, area and population affected given sea-level rise equivalent to global mean temperature rises of 1.5, 2.0 and 3.0 °C with respect to pre-industrial for three ensemble members of a modified A1B scenario. Annual climate variability today (with approximately 1.0 °C of warming) is potentially more important, in terms of coastal impacts, than an additional 0.5 °C warming. In coastal Bangladesh, the average depth of flooding in protected areas is projected to double to between 0.07 and 0.09 m when temperatures are projected at 3.0 °C compared with 1.5 °C. In unprotected areas, the depth of flooding is projected to increase by approximately 50% to 0.21–0.27 m, whilst the average area inundated increases 2.5 times (from 5 to 13% of the region) in the same temperature frame. The greatest area of land flooded is projected in the central and north-east regions. In contrast, lower flood depths, less land area flooded and fewer people are projected in the poldered west of the region. Over multi-centennial timescales, climate change mitigation and controlled sedimentation to maintain relative delta height are key to a delta’s survival. With slow rates of sea-level rise, adaptation remains possible, but further support is required. Monitoring of sea-level rise and subsidence in deltas is recommended, together with improved datasets of elevation.