Commercial Capital Research Articles

Spatial distribution of heatwave vulnerability in a coastal city of Bangladesh

While extreme heat events received wider attention in recent years, understanding heatwave vulnerability is still a challenging task that requires a clear understanding of a range of location-dependent climatic, socio-economic, physiological, and environmental parameters. This study investigates the spatial distribution of heatwave vulnerability in Chattogram City Corporation (CCC) — the commercial capital of Bangladesh. A heatwave vulnerability index (HVI) was developed, including various parameters related to three latent variables — exposure, sensitivity, and adaptive capacity — derived using remote sensing and socio-economic data. Factor analysis was performed to assess all parameters related to HVI. Besides, spatial autocorrelation, cluster and outlier analyses, and hot spot analysis were carried out to investigate the spatial distribution of HVI. This study shows a spatial distribution of HVI in CCC, which is spatially associated with various individual parameters. A total of seven wards (smallest administrative zone of CCC) were found to be very highly vulnerable to the heatwave. This study further reveals that heatwave vulnerability is randomly distributed throughout the city, although the high land surface temperature is concentrated in the existing built-up areas. It also identified three major hot spots of heatwave vulnerability in CCC. The methodology and findings of this study will be of interest to the policymakers and city planners to prepare mitigation plans, policies, and strategies to mitigate this hazard.

Anthropogenic drivers and impacts of urban flooding- A case study in Lower Kelani River Basin, Colombo Sri Lanka

Flooding is the most frequent natural disaster among the top ranking disasters causing destructive effects on people and property of Sri Lanka. Colombo, the commercial capital of Sri Lanka and surrounding suburban areas were experiencing a significant flood events during the last couple of decades. The intensified anthropogenic activities have accelerated severity and frequency of recent floods. Therefore this study was attempted to investigate the pressure generated by the population on the land by human activities causing frequent and severe flooding in Kolonnawa DS Division, Sri Lanka. A questionnaire survey and focus group discussions were carried out to collect primary data whilst collecting secondary data such as long term annual flood peak records, flood inundation data from different government agencies. The gridded population data was obtained from Oak Ridge National Laboratory (LandSacn) from 2000 to 2018 to examine the population pressure generated from the commercial capital to the study area. GIS and Remote Sensing based spatial analysis such as Change Detection, Normalized Difference Vegetation Index (NDVI), Normalized Difference Built-up Index (NDBI), Zonal Statistics and Concentric Circles were used interactively in data analysis. The results reveled that there is an influence of anthropogenic activities of area on recent flood events, severity and damages. Results of NDVI and NDBI analysis depicted a significant decline in green cover. Marshy lands have decreased by 42% from 2005 to 2017. The study further indicated a conversion of paddy and wetlands in to home gardens from 1972 to 2018 due to suburbanization. The decreasing trend of marshy lands, home gardens and paddy lands occurred due to the population pressure generated from the commercial city. Hence, the results of the study would be useful for policy makers and urban planners in developing future flood mitigation plans in study area.

Eric Williams and William Forbes: copper, colonial markets, and commercial capitalism†

AbstractEric Williams placed the Caribbean centre stage in discussions of Britain's industrial revolution and historians are increasingly persuaded by his intuition that the Atlantic trading system, underpinned by enslaved labour, played a major role. Early critics focused discussion on the profits of the slave trade but his thesis was broader, and more sophisticated, than they acknowledged. It left room for linkages of many kinds and it is now time to take a broader look at the connections between the rise of merchant capitalism, in which slavery played a central role, and British economic growth. This study looks at one small, fast‐growing industry, wrought copper, largely through the lens of William Forbes, a London smith. Quantitative data from output and trade records are combined with Forbes's business records to show how the demands of sugar cultivation, a particularly concentrated form of agro‐industrial activity, stimulated the development of a supply network which chained thousands of workers in Cornwall, South Wales, Bristol, and London to enslaved labour in the fields and factories of the Caribbean. Market opportunities allowed Forbes to amass great wealth but also directed investment, innovation, and the accumulation of skills that shaped Britain's particular path to industrial revolution.

“A Great Injustice”: Urban Capitalism and the Limits of Freedom in Nineteenth-Century New York City

Seneca Village was the largest African American landowning community in New York City until it was destroyed to build Central Park. Although it has largely been overlooked, Seneca Village reframes the early history of American capitalism at the intersection of race, freedom, and urban development, diversifying the narrative to place African American city-dwellers as actors at the center of the narrative. Real estate capitalism made Seneca Village possible, with residents using it as a means to social, political, and economic advancement, but it also destroyed Seneca Village. That paradox reveals how an emerging American urban commercial capitalism consolidated power in places Seneca Villagers could not access even when they tried. These men and women played critical, yet unacknowledged, roles as the whole nation struggled to navigate multiple visions of capitalism, their inherent inequalities, and their implications for the future.

Perceptions of Food Waste Reduction in Sri Lanka’s Commercial Capital, Colombo

In 2019, Sri Lanka introduced two policies that referred to food waste and the need to reduce it. To understand key stakeholders’ readiness in this context, this study analyzed the food waste perceptions of private and public sectors in Colombo (open markets, supermarkets, hotels, restaurants, canteens, food caterers and key authorities). Interviews were carried out with operational managers and public officials, as well as other stakeholders who have roles in food waste redistribution and reuse, such as NGOs and the livestock sector. So far, the food-waste-related policy recommendations lack an operational inter-institutional home which can build on measures, like standards, regulations and incentives. Thus, most food waste reduction initiatives are initiated by NGOs or by the private sector, e.g., by larger hotels and supermarket chains. These entities were ready to lead by example, based on the understanding that urban food waste is an internal (financial) management challenge. Among smaller local entities, food waste was perceived more as an external issue to be handled by the city’s waste collection services. Although perceptions varied between entities generating smaller or larger quantities of food waste, there was general agreement that suboptimal capacities and mechanisms to quantify, monitor and cost food waste generation appeared to be obstacles for in-depth awareness creation and action. There was significant interest in communication platforms for cross-sectoral learning, win/win collaborations with reliable collection (reuse) services that are currently operational, such as those provided by piggeries, as well as surplus redistribution initiatives if food safety and related liabilities can be addressed effectively.

URBAN FOOTPRINT OF MUMBAI - THE COMMERCIAL CAPITAL OF INDIA

Urban footprint refers to the proportion of paved surface (built up, roads, etc.) with the reduction of other land use types in a region. Rapid increase in the urban areas is the major driver in landscape dynamics with the significant erosion in the quality and quantity of the natural ecosystems. The urban expansion process hence needs to be monitored, quantified and understood for effective planning and the sustainable management of natural resources. Cities and towns have been experiencing considerable growth in urban area, population size, social aspects, negative environmental and geographical in?uence, and complexity. Mumbai, the commercial capital of India, has experienced a spurt in infrastructural and industrial activities with globalization and opening up of Indian markets. Unplanned urbanization has resulted in dispersed growth inperi-urban pockets due to socio-economic aspects with the burgeoning population of the city. Consequent to this, there has been an uneven growth pattern apart from the increase in slums in and around the city. This has necessitated the understanding of the urbanization pattern and process focusing especially on the expanding geographical area, its geometry and the spatial pattern of its development. This communication discusses the urban footprint dynamics of Mumbai using multi-temporal remote sensing data with spatial metrics. Land use analysis indicated a decrease of vegetation by 20% with an increase in urban extent by 155% during the last three decades. Landscape metrics aided in assessing the spatial structure and composition of the urban footprints through the zonal analysis by dividing the region into four zones with concentric circles of 1 km incrementing radius from the city centre. The study reveals a significant variation in the composition of the urban patch dynamics with increasing complexity and aggregation of urban area at the centre and sprawl at the outskirts. Shannon’s entropy further confirms of sprawl with time. Further zoning with the circular gradients aided in understanding the transition process of land use categories into urban patch.

Book Review: A Brief History of Commercial Capitalism by Jairus Banaji

Book Review: A Brief History of Commercial Capitalism by Jairus Banaji

URBAN FOOTPRINT OF MUMBAI - THE COMMERCIAL CAPITAL OF INDIA

Urban footprint refers to the proportion of paved surface (built up, roads, etc.) with the reduction of other land use types in a region. Rapid increase in the urban areas is the major driver in landscape dynamics with the significant erosion in the quality and quantity of the natural ecosystems. The urban expansion process hence needs to be monitored, quantified and understood for effective planning and the sustainable management of natural resources. Cities and towns have been experiencing considerable growth in urban area, population size, social aspects, negative environmental and geographical in?uence, and complexity. Mumbai, the commercial capital of India, has experienced a spurt in infrastructural and industrial activities with globalization and opening up of Indian markets. Unplanned urbanization has resulted in dispersed growth inperi-urban pockets due to socio-economic aspects with the burgeoning population of the city. Consequent to this, there has been an uneven growth pattern apart from the increase in slums in and around the city. This has necessitated the understanding of the urbanization pattern and process focusing especially on the expanding geographical area, its geometry and the spatial pattern of its development. This communication discusses the urban footprint dynamics of Mumbai using multi-temporal remote sensing data with spatial metrics. Land use analysis indicated a decrease of vegetation by 20% with an increase in urban extent by 155% during the last three decades. Landscape metrics aided in assessing the spatial structure and composition of the urban footprints through the zonal analysis by dividing the region into four zones with concentric circles of 1 km incrementing radius from the city centre. The study reveals a significant variation in the composition of the urban patch dynamics with increasing complexity and aggregation of urban area at the centre and sprawl at the outskirts. Shannon’s entropy further confirms of sprawl with time. Further zoning with the circular gradients aided in understanding the transition process of land use categories into urban patch.

Economic Systems of Muslims in History

Abstract During its long history, the Islamic world experienced three different economic systems. The original Islamic economy introduced by the Qurʾān and other classical sources of Islam, was a form of sui generis, commercial, pre-industrial and ethical capitalism. Evidence for this will be presented from the classical sources of Islam as well as from the history of Islamic economic thought. In later centuries it is possible to observe a transition from this unique capitalism towards more centralised structures, which reached its zenith with the Ottoman proto quasi-socialism. Most recently, after the Second World War, newly independent Muslims re-invented Islamic finance. Although an almost three trillion USD industry, so far this has been basically an imitation of conventional finance. Whether a truly modern and Islamic capitalism or another system will emerge from this, remains to be seen. Ample historical evidence across the Islamic world from West Africa to Indonesia is provided.

Risk Taking in Venture Philanthropy: The Influence of Human Capital and Gender

Relying on human capital and gender role congruity theory, this paper seeks to identify the extent to which the top management team’s human capital affects the risk-taking orientation of impact-focused investors. We then look at how gender moderates this relationship. We empirically ground our analysis in the context of venture philanthropy (VP) firms, a subset of the broader impact investing sector which is more hands-on and focused on funding social ventures. Relying on a combination of survey data to measure the VP firm’s risk orientation, and biographical data to identify top managers’ human capital, we find that neither commercial nor social human capital alone affect the risk orientation of VP investors. However, results show that gender, independently of the human capital, positively affects risk-taking when top managers are women. In the case of men, human capital plays a role. Contrary to expectations, teams with more men who have higher human capital garnered in a commercial endeavor have a lower risk-taking orientation while those with more human capital garnered in the social sector increases take higher risks. This suggests the existence of a gender bind dilemma in the social investment sector both for men and for women.

Sport and the Torres Strait: Thursday Island, Island Studies, the Archipelagic Turn, and Identity

From the late 1950s onward, sport contributed to racial integration on Thursday Island, the administrative and commercial capital of the Torres Strait in northern Australia. Following their exclusion from the capital prior to, during, and immediately after the Second World War, Islanders began to move to Thursday Island in this period. As a homogenizing force, sport also helped to build a new local identity by connecting Thursday Island not only with the outer islands but also with close regional neighbours in Cape York Indigenous communities and in New Guinea. Empirically, this paper draws on archival documents, newspaper reports and oral history interviews. Conceptually, it is guided by the field of island studies, which emphasizes the uniqueness and significance of islands historically, culturally and in other spheres, and by the archipelagic turn in island studies that theorizes island interconnectivity.

Knowledge, attitudes and bite prevention practices and estimation of productivity of vector breeding sites using a Habitat Suitability Score (HSS) among households with confirmed dengue in the 2014 outbreak in Dar es Salaam, Tanzania.

BackgroundThe frequency and magnitude of dengue epidemics has increased dramatically throughout the tropics in the past 40 years due to unplanned urbanization, globalization and lack of effective mosquito control. The commercial capital of Tanzania, Dar es Salaam, is now experiencing regular dengue outbreaks. Three dengue serotypes have been detected in Dar es Salaam (DNV 1, 2 and 3). Without adequate vector monitoring and control, further outbreaks will certainly occur.Methods/FindingsA case series study followed 97 individuals with confirmed dengue fever (NS1 and/or IgM on rapid diagnostic test and/or PCR positive) to their households in Kinondoni, Dar es Salaam during the 2014 outbreak from a random sample of 202 confirmed cases at Mwananyamala Hospital. Kinondoni wards of Manzese, Mwananyamala, Tandale and Mabibo had the highest number of confirmed cases: 18, 13, 13 and 9 respectively. Individuals were interviewed by questionnaire on dengue prevention practices and houses were inspected for mosquito breeding sites to validate a Habitat Suitability Score (HSS). This is a tool devised to predict the productivity of any potential breeding habitats (PBHs) before the rains begin.There were 12 /312 positive Aedes breeding habitats. Drums/barrels, flowerpots and tyres were the most common breeding habitats. The HSS correctly identified 9/12 of Aedes breeding habitats. Larviciding is already conducted in urban Tanzania for malaria control and the HSS may be a useful means to train individuals on productive Aedes aegypti breeding sites should this program be extended to include dengue control.The population remains poorly informed about dengue transmission and prevention: 22% of respondents said dengue is spread from one person to another and 60% first heard about dengue when already sick. Less than 20% of respondents used personal protection and >80% thought bednets protected against dengue. Mobile phones were owned by almost all individuals followed up and have the potential of being the prime medium for dissemination of information on dengue prevention.

Road transport energy consumption and vehicular emissions in Lagos, Nigeria: An application of the LEAP model

The “Avoid”, “Shift” and “Improve” (A-S-I) approach is an effective method for transforming an unsustainable transport system to a sustainable one. This study intends to examine the possible impact of the A-S-I policy measures in transforming the transportation system in Lagos - the most populous city and the commercial capital of Nigeria. The study employs the Long Range Energy Alternative Planning (LEAP) model to project future energy demand and greenhouse gas emissions to determine the most effective A-S-I option for the city. We construct a business-as-usual scenario for Lagos as well as sustainable road transport alternative policy scenarios. The results show that Lagos' biggest obstacle to achieving its emission reduction target is the presence of very old vehicles on its roads. Our analysis shows that emission reduction in the road transport sector in Lagos is sensitive to vehicle survivability rate (i.e. the fraction of vehicles of a certain age still driven). We conclude that unless the age limit of vehicles in Lagos reduces from 40 years to 22 years, vehicle growth rate from 5% to 2% and mileage by 2% per year from 2020 to 2032, Lagos may not achieve its target of 50% emission reduction by 2032.

Daytime concentrations of minor and trace elements in atmospheric aerosols at four sampling sites of Dar es Salaam, Tanzania

Tropospheric aerosols (total suspended particulate, TSP) were sampled at four sampling sites of various anthropogenic impact (industrial, commercial, heavy trafficked, and mixed urban influence), located in Dar es Salaam, the commercial capital of Tanzania. Air concentrations of minor and trace elements (Al, As, Br, Ca, Cd, Cl, Cr, Cu, Fe, K, Mg, Mn, Na, Ni, Pb, S, Si, Sb, and Zn) in TSP were determined by means of wavelength-dispersive X-ray fluorescence (WDXRF) spectrometry and inductively coupled plasma atomic emission spectrometry (ICP-AES). From these data, the main ionic composition of particulate matter was inferred by means of a species correlation/ratio-derived approach, based on former studies of the region. Enrichment factors, bivariate correlations, diagnostic ratios, and chemical mass closures were calculated utilizing the concentration data of TSP constituents for each site in order to reveal the emission sources. A couple of diagnostic ratios (Ni/Cd, Zn/Cd, Br/Ni, Ni/Sb) were useful for source identification, e.g., motor vehicle exhaust and non-exhaust emissions. Significant increases in concentrations of As, Br, Cr, Cu, Mn, Ni, Pb, and Zn were observed, as compared to results for the city before 2010. Moreover, first-time air levels are reported for Cd and Sb, which are important markers of non-exhaust emissions. Air quality indices and calculations with the AIRQ+ model have foreseen increases in the negative health effects of the sensitive groups of the local population at the study areas, especially those with heavy traffic, industrial, and/or mixed urban influence.

Little Cold Warriors: American Childhood in the 1950s by Victoria M. Grieve

Reviewed by: Little Cold Warriors: American Childhood in the 1950s by Victoria M. Grieve Joel P. Rhodes Little Cold Warriors: American Childhood in the 1950s. By Victoria M. Grieve. New York: Oxford University Press, 2018. x + 206 pp. Cloth $74. Unsatisfied with nostalgic tendencies that can limit our perceptions of American childhood in the 1950s to simply reflexive duck-and-cover civil defense drills or baby boomer sentimentality, Victoria Grieve thoughtfully examines the neglected ways youth were politicized and mobilized as little cold warriors in the global contest between the capitalist West and communist East. Grieve's work advances along the path of Marilyn Irvin Holt's 2014 book Cold War Kids: Politics and Childhood in Postwar America, 1945-1960, strengthening the case for the 1950s as a dynamic era in children's history. American children were not simply complacent victims menaced by Soviet indoctrination and the specter of nuclear war; rather, in Grieve's view, young people exercised pronounced agency in waging Cold War, demonstrating levels of civic engagement and defense work generally associated with the home front in World War II. As the US harnessed every resource at the republic's disposal, culture emerged as a theater of battle; over this contested terrain Grieve traces how childhood was weaponized to favorably influence foreign opinion and demonstrate American superiority abroad. Public and private interests enlisted American youth in new and unprecedented degrees of public diplomacy: trick-or-treating for UNICEF, exchanging original art, photo albums, and pen-pal correspondence with children around the world, donating books to restock war-torn European libraries and used clothing for refugees, or various types of people-to-people exchanges. In these roles, Grieve argues, American children operated as important ambassadors, cultural diplomats, and representatives of their nation. Akin to Margaret Peacock's 2014 volume Innocent Weapons: The Soviet and American Politics of Childhood in the Cold War, one of Grieve's chief arguments centers on the inherent paradox of innocence when childhood is politicized. Just as youthful innocence needed to be protected—a powerful rationale for containing communism—so too did that imagined innocence constitute the basis for these political activities on the state's behalf. But because adults preferred to see young diplomats as apolitical and free from state sponsorship (as opposed to the perception of brainwashed Soviet children), such youthful volunteerism was framed as an authentic gesture fostering world peace. [End Page 155] The five core chapters begin with the in loco parentis role of comic books in socializing children to America's new obligations as global superpower. Grieve sees The Lone Ranger specifically as a useful allegory for modeling "benevolent supremacy," a vision of the US as savior and civilizer, not conqueror or colonizer. While the idea of postwar children making meaning out of Old West narratives found in television, movies, and literature is well founded, I suggest an alternate childhood reading of the popular Western genre in view of events in the sixties. Perhaps, as writer Tom Engelhardt posits, the ultimate victory of normally peaceful but outnumbered "good guys" shooting it out against ruthless "bad guys" could be understood by children as justification for the winner's use of violence and validation of his virtue. Grieve's most convincing work focuses on children's involvement in several so-called "camouflaged" propaganda efforts, where governmental agencies, semiprivate organizations, and individuals indirectly collaborated in disseminating pro-American messages overseas and offsetting more overt Soviet information operations. The chapter on international, child-to-child artwork exchange programs uses the group Art for World Friendship (AWF) as an excellent case study for the ways in which the universal language of childhood creativity functioned to simultaneously cultivate international goodwill while showcasing American prosperity. Little Cold Warriors similarly breaks new ground in the chapter examining the Advertising Council's promotional campaigns as a type of citizenship training, particularly that nonprofit, public relations organization's Crusade for Freedom. In prolific, pro-business messages commonly targeting American schoolchildren, the Advertising Council's gospel of commercial market capitalism familiarized 1950s youth with a fundamental Cold War notion: patriotism demanded consumerism. As Grieve makes clear, the Crusade for Freedom—one of the era's many all-American contests and...

American Commerce, American Empire: Late 19th‐Century Merchant Organizations and Trade Policy

AbstractThe American debate over free trade and protectionism has taken many forms, but it is particularly instructive when it occurs within a single sector of the economy, pitting allied economic interests against each other. That occurred in the shipping industry in the 19th century when shippers and shipbuilders fought each other over trade‐related questions: subsidies for shipbuilding and reciprocal trade agreements with foreign nations. Shipbuilders wanted protection and subsidies; shippers wanted the freedom to make use of cheaper foreign vessels for trade and to develop trade agreements. We show how these opposing forces stymied each other and prevented the shipping industry from taking an active, unified role in national politics. These particular intra‐industry debates reveal broader divisions within the business community over the relationship between business and government under modern commercial capitalism.

Young Peoples' support for a smoke-free campus policy: A case for smoke-free campuses in the statewide smoking law in Lagos State, Nigeria.

Background:Smoke-free policies are increasingly being enacted in several countries. In 2014, Lagos State, the commercial capital of Nigeria, enacted a statewide smoke-free policy; however, university campuses were excluded from the list of public places where smoking would be disallowed. This study aimed to assess students’ support for smoke-free campus policies, their attitudes, and exposure toward secondhand smoke (SHS).Methods:This cross-sectional descriptive study was carried out among 421 university undergraduates in two premier universities in the state. Respondents were selected using a multistage sampling method, and the data were collected using a pretested self-administered questionnaire.Results:Many (55.4%) of the respondents agreed that students who are non-smokers have the right to inhale smoke-free air on campuses and expressed feelings of irritation (57.1%) or anger (17.1%) when exposed to SHS on campus. Majority (80.1%) of the respondents were in support of a smoke-free policy on their campus and in favor of a ban on smoking in enclosed spaces on campus (79.6%). Exposure to SHS on campus was high, as one in five respondents were exposed to SHS in their hostel rooms (19.9%) and 44.9% were exposed in outdoor campus spaces in the preceding week. There was a statistically significant association between respondents’ age, gender, smoking status, and attitudes toward SHS and support for a smoke-free campus policy.Conclusion:Although the majority of the students were non-smokers, significant exposure to SHS on campuses still exists. There is a huge support for smoke-free campus policies. The state government should consider including campuses on the list of smoke-free public spaces in the review of the statewide smoking law.

City Growth and the Plight of Street Vendors in Dar es Salaam, Tanzania: The Need for Policy Coordination

Dar es Salaam, the commercial capital of Tanzania, is growing very fast. One of the sectors that have changed remarkably in recent years is the transport sector. A mega Bus Rapid Transit (BRT) project was recently introduced to help in solving traffc jam problems in the city. But as the City grows, some groups become more vulnerable than others. One of these groups is that of street vendors. In order to give way for the BRT project, hundreds of street vendors were moved by force from the Ubungo commuter bus terminal – which used to be a hub of street vendors – and relocated to a newly constructed market in a place called Mawasiliano or Simu 2000. Within the frst week of the exercise there was chaos, and the feld force police had to be deployed to restore order. Using in-depth interviews, focus group discussion, participant and non-participant observation, and quasi-experimentation, a study was conducted to explore the coordination of the whole exercise and how it affected the welfare of the relocated vendors. The study found two contradicting orders (one from the Municipal Mayor and the second from the District Commissioner) led to chaos and a lot of disturbance to the vendors. It is concluded that uncoordinated policies at the municipal level adversely affect the welfare of the street vendors. Lack of a comprehensive written national policy to manage the activities of informal traders in Tanzania is seen to be a major problem, calling for coordinated policies at the municipal level.

Owners, creditors and traders: Women in late colonial Calcutta

This article tries to reconstruct the world of the property-owning, mortgage-holding and money-lending women in late colonial Bengal and especially in Calcutta, the commercial capital of British India until the First World War. It argues that as all poor women occupying the urban space were not either sex workers or domestic servants, similarly all middle-class women in colonial Calcutta were not dependent housewives, teachers and doctors. At least a section of them engaged in other gainful economic activities. However, existing scholarship sheds very little light on those women who chose other means of survival than the bhadramahila: those who bought and sold houses, lent money for interest, acquired mortgages, speculated in jute trade and even managed indigenous banking business. Evidence of court records suggests that they, along with the lady teacher, the lady doctor, the midwife and the social worker or later members of political organisations, could be found in considerable numbers in late colonial Calcutta. Due to the enactment of stringent laws to control moneylending, on the one hand, and the commercial decline of Calcutta, on the other hand, these women were possibly driven out of the shrinking market of the 1940s and 1950s.

The use of watershed geomorphic data in flash flood susceptibility zoning: a case study of the Karnaphuli and Sangu river basins of Bangladesh

The occurrence of heavy rainfall in the south-eastern hilly region of Bangladesh makes this area highly susceptible to recurrent flash flooding. As the region is the commercial capital of Bangladesh, these flash floods pose a significant threat to the national economy. Predicting this type of flooding is a complex task which requires a detailed understanding of the river basin characteristics. This study evaluated the susceptibility of the region to flash floods emanating from within the Karnaphuli and Sangu river basins. Twenty-two morphometric parameters were used. The occurrence and impact of flash floods within these basins are mainly associated with the volume of runoff, runoff velocity, and the surface infiltration capacity of the various watersheds. Analysis showed that major parts of the basin were susceptible to flash flooding events of a ‘moderate’-to-‘very high’ level of severity. The degree of susceptibility of ten of the watersheds was rated as ‘high’, and one was ‘very high’. The flash flood susceptibility map drawn from the analysis was used at the sub-district level to identify populated areas at risk. More than 80% of the total area of the 16 sub-districts were determined to have a ‘high’-to-‘very-high’-level flood susceptibility. The analysis noted that around 3.4 million people reside in flash flood-prone areas, therefore indicating the potential for loss of life and property. The study identified significant flash flood potential zones within a region of national importance, and exposure of the population to these events. Detailed analysis and display of flash flood susceptibility data at the sub-district level can enable the relevant organizations to improve watershed management practices and, as a consequence, alleviate future flood risk.