Flood Mapping in the Coastal Region of Bangladesh Using Sentinel-1 SAR Images: A Case Study of Super Cyclone Amphan

Floods are triggered by water overflow into drylands from several sources, including rivers, lakes, oceans, or heavy rainfall. Near real-time (NRT) flood mapping plays an important role in taking strategic measures to reduce flood damage after a flood event. There are many satellite imagery based remote sensing techniques that are widely used to generate flood maps. Synthetic aperture radar (SAR) images have proven to be more effective in flood mapping due to its high spatial resolution and cloud penetration capacity. This case study is focused on the super cyclone, commonly known as Amphan, stemming from the west Bengal-Bangladesh coast across the Sundarbans on 20 May 2020, with a wind speed between 155 -165  gusting up to 185 . The flooding extent is determined by analyzing the pre and post-event synthetic aperture radar images, using the change detection and thresholding (CDAT) method. The results showed an inundated landmass of 2146 on 22 May 2020, excluding Sundarban. However, the area became 1425 about a week after the event, precisely on 28 May 2020 . This persistency generated a more severe and intense flood, due to the broken embankments. Furthermore, 13 out of 19 coastal districts were affected by the flooding, while 8 were highly inundated, including Bagerhat, Pirojpur, Satkhira, Khulna, Barisal, Jhalokati, Patuakhali and Barguna. These findings were subsequently compared with an inundation map created with a validation survey immediately after the event and also with the disposed location using a machine learning-based image classification technique. Consequently, the comparison showed a close similarity between the inundation scenario and the flood reports from the secondary sources. This circumstance envisages the significant role of CDAT application in providing relevant information for an effective decision support system

Role of social capital in empowering rural women through income-generating activities in Sylhet District, Bangladesh

Social capital has been recognized as an essential towards empowering rural women in the Sylhet District of Bangladesh. It facilitates their engagement in various Income Generating Activities (IGAs) as means of empowerment. IGAs have therefore, become an essential empowerment tool among rural women in the Sylhet District of Bangladesh because it gives them expanded access to resources and enhanced capabilities for self- reliance at both individual and collective levels. Majority of women have very little chance to take part in intra-household activities, socio-economic activities and have limited inter-linkage with people due to social, cultural and religious restrictions. This thesis examined the role played by social capital and participation towards the empowerment of women through IGAs in Bangladesh with specific focus on rural women in Sylhet District, Bangladesh. Therefore, this study aims to: (i) to describe the demographic characteristics of rural women participating in different IGAs in Sylhet District of Bangladesh, (ii) to measure the dimensions of social capital, participation and levels of empowerment in IGAs among rural women in the District under study (iii) to examine the relationship between social capital, participation and women empowerment in the study area, (iv) to examine the impacts of social capital (bonding, bridging and linking) on psychological and financial assets among rural women in the study area, (v) to explore the effect of socio-demographic factors on women empowerment through IGAs in the study area, and (vi) to examine the present socio- economic challenges hindering women empowerment through IGAs in Sylhet District of Bangladesh. This study is mainly a quantitative research, however, qualitative data were collected via a semi-structured interview for support and validation purpose. The study was conducted in two phases: quantitative survey which was followed by a qualitative interview. The study used questionnaire as its main instrument of quantitative data collection from a total of 328 randomly selected respondents. In the qualitative phase, the in-depth interview method was used for data collection and a total of twelve (12) informants were purposively selected and interviewed. The Pearson correlation analysis was measured to explain the relationships between participation, social capital and women empowerment. A multiple linear regression analysis was also deployed to identify the highest contributing factors of social capital towards women empowerment by using SPSS version-22 software and the qualitative thematic analysis were done by Nvivo software. Three proxies of social capital (bonding, bridging and linking) were measured in this study. The results show that more than 50% of the women had high levels of bonding. Bonding social capital was found to be the most contributing factor to women empowerment. The descriptive analysis of bridging social capital reveals that only 4.6% of the women were in the lower level of bridging social capital, with 40.4% being in the higher level of bridging and 55% in the moderate level. 63.2% of the women were in the lower level of linking, 30% had a moderate level and 6.8% had a high level of linking social capital. Participation in IGAs (subjective and objective) and bridging were also found to be significant in enhancing the women empowerment based on the results of the study. With regards to the psychological and financial dimensions of empowerment, the results indicate that level of bonding determines financial assets among rural women in the study area while the three dimensions of social capital (bonding, bridging and linking) altogether determines psychological assets among the rural women in South Surma Upazila of Sylhet district in Bangladesh. The data analysis showed that there is a significant relationship between participation, social capital and women empowerment in the Sylhet District of Bangladesh. The analysis equally indicated that among the socio- demographic factors, women’s level of education, marital status, personal income, credit received, training received and participation in IGAs determines their levels of empowerment. Taken together the findings of this study suggested that bonding, bridging, and linking are directly related to empowerment of women who are participating in different IGAs. The overall results indicated that the conceptualizations of bonding, bridging, linking and participation have provided a good understanding of empowerment among women as most of the findings appear to suggest. Since the level of bridging and linking among rural women ranged from medium to low levels, community development policy makers might focus on building and facilitating bridging and linking as dimensions of social capital in order to facilitate the empowerment of women in Bangladesh

Empowering rural women's involvement in income generating activities through BRAC microfinance institution in Sylhet District, Bangladesh

This article presented the findings on the role of microcredit financial assistance, specifically from Bangladesh Rural Advancement Committee (BRAC) Micro-finance institution to assist rural women in Sylhet District, Bangladesh involved in income generating activities. The impact on their socio-economic empowerment, the constraints of rural women in having access to loan service from micro-finance institutions and loan repayment process will be discussed. The target population of the study was those women who had availed microcredit facilities from some microcredit providing institutions or organizations in the study area. Survey method was used as a technique for data collection. The results of the analysis indicate that participation of rural women in micro-finance assisted income generating activities contributes towards socioeconomic empowerment. It also showed that most of the rural women who availed the facility of microcredit finally became empowered through acquiring the confidence level, business skills, decision making power, and self-esteem. The findings also showed that microcredit has significant impact on the up lift of socio-economic empowerment of the women’s in Sylhet district. However, constraints of rural women in accessing loan and loan repayment process should be properly addressed by the stakeholders to improve the contribution of micro- finance institutions for achieving sustainable development goal. Hence, accessing microcredit has been able to empower women financially and it is suggested that microcredit loan be made accessible to poor women who are keen to uplift the family’s economic wellbeing

Arsenic contamination in groundwater and its proposed remedial measures

Arsenic contamination occurs in groundwater of Bangladesh mainly from the alluvial and deltaic sediments. Arsenic contamination of groundwater in Bangladesh was first detected more than a decade ago and the 'shallow tube wells' were reported as the main source of arsenic contaminated water. From the nutritional and metabolic points of view, arsenic is likely to adversely affect human health and nutrition. Up to now, several studies have been carried out on this context; however, inadequate knowledge on arsenic sources, mobilization and transport still remains as a constraint due to lack of data, information and technological advances. Thus, a review study has been undertaken on the sources of arsenic, its causes, mobilization, transport, effects on human health, arsenic test procedures and removal methods, in the context of groundwater contamination in Bangladesh, and finally sustainable remedial measures of arsenic have been proposed. This study suggests that laboratory facilities for testing of arsenic and effects of enhanced groundwater pumping, phosphate fertilizer etc., need to be updated, expanded and studied. This review work is significant to further knowledge improvement, as the topic is general and worldwide. It can be concluded that the integration of the proposed remedial measures with the national geographic information system interface database relating to arsenic for analysis, production of hazard maps, and dissemination on television show for the planners, engineers, managers, field supervisors and affected people, can reach at the sustainable solution for mitigating arsenic and associated problems successfully in Bangladesh

Environmental flow requirements assessment in the Halda River, Bangladesh

Environmental flows have scarcely been considered in river water management in Bangladesh. This study attempts to assess the environmental flow requirements in the Halda River, Bangladesh. Thus, the objectives are to estimate the Halda River flow with different return periods/probabilities, which was done using the log-Pearson Type III distribution (LPIII), and to mitigate the environmental problems in the Halda River using the building block method. The LPIII distribution was used to estimate the expected extreme and satisfactory flows for fish habitat at Panchpukuria station and the expected extreme water levels at Panchpukuria, Narayanhat, Telpari and Enayethat stations. It was found that floods are likely to occur at least once in 2.1, 1.02, 1.75 and 1.25 years at Panchpukuria, Narayanhat, Telpari and Enayethat stations, respectively. The results of flow and water quality analyses suggest that environmental flow requirements cannot be achieved in this river throughout the year. The environmental flow requirements and conservation of fish resources can be achieved by implementing the suggestions provided in conjunction with a comprehensive awareness programme, investigations and trade-off analyses being among the suggestions