Masudur Rahman | University of Dhaka, Bangladesh (original) (raw)

Presentation Papers by Masudur Rahman

American Association of Geographer (Annual Meeting, New Orleans 2018), 2018

The purpose of the study is to understand the ecological aspects of Visceral Leishmaniasis (VL) a... more The purpose of the study is to understand the ecological aspects of Visceral Leishmaniasis (VL) and to identify the environmental factors of VL in Bangladesh. Three hyperendemic upazilas (sub-district), namely Fulbaria, Trishal and Gaffargaon of Mymensingh and one relatively low endemic upazila (Sreepur) of Gazipur districts constitute the study area. We used maxent to develop the distribution model for VL and employed jackknife test of variable importance to isolate environmental variables affecting Visceral Leishmaniasis in the country. Nineteen bioclim variables, soil drainage, general soil type, soil moisture, soil reaction/pH, land cover, NDVI, NDWI, topographic wetness index (TWI), land surface temperature and elevation were used as the environmental layers. In order to model the disease distribution, human (VL) cases were used as a proxy for presence location points of P. argentipes, obtained by GPS measurements in extensive field visits. The model performance was evaluated by the area under the curve (AUC) of the receiving operator curve (ROC) and by a one-tail binomial test with the null hypothesis that the model does not predict the test/predicted presence points better than a random model.
This first ever attempt of identifying environmental influence on VL distribution in Bangladesh provides a framework for tackling the ecological aspects of the disease. More focus can be given to the identified potentially risky areas in order to prevent a resurgence of the disease in coming years.

American Meteorological Society, 2017

While national summaries of lightning fatalities have been published for a number of other countr... more While national summaries of lightning fatalities have been published for a number of other countries in recent years, no such summary exists for Bangladesh. Knowledge of the fatality statistics for Bangladesh during a long period will assist in understanding the lightning threat here and in similar nearby regions of the world. In order to address this lack of data, a summary of lightning-caused fatalities in Bangladesh is presented for the most recent 27-year period. To be explored is whether a large number of fatalities occur in Bangladesh due to its large rate of lightning occurrence and high population density. The location, time of day, week, and month as well as activity, gender, age, and other aspects of the fatalities will be collated by year. It is expected that as some data collection methods improve, there will be a tendency for larger frequencies of fatality reports to be identified in the later years. One of the issues to be considered, if possible, is the availability of a safe location for agricultural workers to reach in case of a thunderstorm. Such safe locations are typically missing in these fields. The fatality data are combined from a variety of sources during this period on a national basis. The main data sources include local literature, disaster reports by Disaster Forum and NIRAPAD, regional civil surgeon offices, regional dailies, and the next most useful dataset is the national dailies. At least a third of the data was available only in the Bengali language, while the rest was obtained from English-language sources. A total of 3086 lightning-related fatalities from 1990 to June 2016 and 2382 injuries since 1990 are included. A complementary AMS Annual Meeting paper by Holle and Islam will consider multiple fatalities during a recent event in May 2016 over Bangladesh. Out of 3086 deaths, the overwhelming majority had died (1225 persons) whilst carrying out farming activities followed by deaths within a house (737 persons). Returning home or walking/resting or wandering in the homestead caused 332 deaths whereas fishing, boating and bathing in the waterbody caused a total of 233 deaths. A previous study by Holle has shown a tendency for multiple fatalities to occur in paddy activities in this region and time of year. The location of lightning fatalities, according to district, indicated that all 64 districts had lightning casualties during the study period (1990-2016) however six districts (Sunamganj, Netrokona, Kishoreganj, Brahmanbaria, Cox’s Bazar and Chapai Nawabganj) experienced the highest causalities, ranging from 164 to 258. It is worth noting that five among these six districts had deaths totaling between 91 and 140 from 1990-2016.

Lightning Fatalities in Bangladesh from 1990 through 2016. Available from: https://www.researchgate.net/publication/312120664_Lightning_Fatalities_in_Bangladesh_from_1990_through_2016 [accessed Apr 17, 2017].

Books by Masudur Rahman

Springer International Publishing, 2017

Global environmental change is expected to have significant impacts on public health. Low income ... more Global environmental change is expected to have significant impacts on public health. Low income countries will be disproportionately affected by such change even though their contribution to global greenhouse gas emission is insignificant relative to developed countries. Visceral leishmaniasis, a vector-borne disease known as kala-azar on the Indian subcontinent, causes a significant burden of mortality and morbidity every year across the world. Approximately 200 million people are said to be at risk of kala-azar in the Indian subcontinent with 25,000– 40,000 cases reported per year. This chapter examines past and present kala-azar incidences in Bangladesh and explores the future vulnerability of the country and its inhabitants under conditions of environmental change. Using published research and 2014 reported kala-azar cases from the Disease Control Unit of the Directorate General of Health Services, this study also attempts to present the epidemiology of kala-azar in Bangladesh. It shows that global environmental changes have the potential to cause deterioration to the social and ecological systems of the country. As a result, the country may suffer from an upsurge of all vector-borne and water-borne diseases, including kala-azar. Because climatic change, in combination with land use change driven by population pressure, is expected to increase, so too will the occurrence of vector-borne diseases such as kala-azar. Additional measures will thus be required to control the vectors, their abundance, and disease transmission. More research is needed if we are to reduce the impact of this fatal disease.

Papers by Masudur Rahman

Kala Azar in South Asia, 2016

The use of spectral vegetation index, namely the Normalized Difference Vegetation Index (NDVI) wa... more The use of spectral vegetation index, namely the Normalized Difference Vegetation Index (NDVI) was applied to detect areas of vegetation cover and Delta Cue was applied to detect areas of vegetation change. The study then reveals that vegetation cover of the area has changed significantly during 1989 to 2010. In this research attempt has been taken to detect the loss of vegetation cover, to determine the trend, nature, rate, location and magnitude of vegetation and subsequent vegetation change detection for the Patuakhali District using multi-temporal, multi-date and multi-sensor aerospace data. Landsat imageries of the year January 1989, January 2001 and January 2010 have been used to find out the difference of vegetation coverage with afforestation and deforestation of Patuakhali District over 20 years. Temporal mapping is driven by remote sensing and Geographic Information System (GIS) to capture and analyze information from modern records. The map and the database have been focu...

Earth Systems and Environment, 2019

Rapidly changing river systems can impact people, property and infrastructures. This study invest... more Rapidly changing river systems can impact people, property and infrastructures. This study investigates bank erosion and accretion of the Padma River in Bangladesh, through space and time, using historical topographic maps, Corona and Landsat images and navigational charts. A geographic information system (GIS) was utilised to quantify the erosion and accretion pattern. In addition, volumetric changes in the riverbed were also investigated. Results indicated that the area of erosion and deposition vary both spatially and temporally. However, erosion was more prominent on the left bank, whilst accretion was high along the right bank, over the study period. Overall, average annual erosion rates were higher than accretion rates (17 km 2 year −1 versus 13 km 2 year −1). The volumes of morphological change for two epochs correspond to a net volume gain of 338.75 million m 3 sediment between 1984 and 1992 but a net loss of 295.20 million m 3 during the period 1992-2008. Regression analysis between bank erosion and mean annual flow, peak discharge and mean flood flow showed that two of the three independent variables were significantly associated with bank erosion. The area of large mid-channel bars increased over time, which may have had a role in shaping erosion and accretion processes of the river. As increased runoff is expected in the future, as a result of enhanced rainfall under warmer climate, knowledge of this work will help to determine the morphological response of fluvial systems in Bangladesh and elsewhere.

International Journal of Climatology, 2017

Satellite-derived lightning data for 17 years (1998-2014) were used to evaluate the relation betw... more Satellite-derived lightning data for 17 years (1998-2014) were used to evaluate the relation between environmental factors and lightning activity over the Bangladesh landmass. Time series convective available potential energy (CAPE) data were extracted from ERA-40 reanalysis data while total and convective rainfalls were obtained from Tropical Rainfall Measuring Mission's monthly products. In addition, the product of CAPE and precipitation was computed and used as an additional variable. Three timescales-monthly, seasonal and annual-were utilized to determine the influence of precipitation and CAPE on lightning activity. The results indicated that CAPE stands out as an important variable at all of these timescales for predicting the occurrence of lightning. The correlation coefficient (r) between CAPE and lightning activity was found to be 0.902 (monthly), 0.703 (pre-monsoon), 0.550 (monsoon) and 0.702 (annual), respectively. Total rain showed strong positive correlation with lightning on monthly scale (r = 0.734) and in the pre-monsoon season (r = 0.701). However, such relationship was moderate during monsoon (r = 0.455). In contrast, convective rain showed slightly higher correlation during monsoon (r = 0.587) compared with that of pre-monsoon season (r = 0.532). Because of strong seasonality in the data, convective rain did not exhibit strong relationship on annual scale (r = 0.227). The product variable (e.g. CAPE × precipitation) showed significant correlation on monthly (r = 0.895) and seasonal scales (r = 0.818 during pre-monsoon and 0.686 in monsoon) but its influence appears to diminish on a longer timescale (r = 0.375). Spatial maps of correlation coefficient revealed significant positive correlation along relatively drier northern parts of Bangladesh. As lightning-related fatality is on the rise, this study, first of its kind, is expected to inform public policy and provide information necessary for effective management of this atmospheric phenomenon to save lives and property in Bangladesh.

Theoretical and Applied Climatology, 2017

Using NASA's TRMM Lightning Imaging Sensor (LIS) data from 1998 to 2014, this paper presents a 17... more Using NASA's TRMM Lightning Imaging Sensor (LIS) data from 1998 to 2014, this paper presents a 17-year lightning climatology of Bangladesh, at 0.5°× 0.5°spatial resolution. Diurnal, seasonal, monthly and annual variations in the occurrence of lightning flashes were explored. The diurnal regime of lightning is dominated by afternoon/evening events. Overall, peak lightning activity occurs in the early morning (0200 LST) and evening (1900 LST). The distribution of lightning flash counts by season over Bangladesh landmass is as follows: pre-monsoon (69.2%), monsoon (24.1%), post-monsoon (4.6%) and winter (2.1%). Flash rate density (FRD) hotspots were primarily located in the north and northeastern parts of Bangladesh, with a maximum of 72 fl km −2 year −1. Spatially, the distribution of FRD increases from the Bay of Bengal in the south to relatively higher elevations (of the Himalayan foothills) in the north. A spatial shift in FRD hotspots occurs with change in season. For example, in monsoon season, hotspots of lightning activity move in a south-westerly direction from their pre-monsoon location (i.e. northeastern Bangladesh) towards West Bengal in India. South and southeastern parts of Bangladesh experience high lightning activity during post-monsoon season due to regional orographic lifting and low-pressure systems (i.e. cyclone) in the Bay of Bengal. To the best of our knowledge, this is the first study focused on LIS-based lightning climatology over Bangladesh. This baseline study, therefore, is an essential first step towards effective management of lightning-related hazards in Bangladesh.

Earth Systems and Environment, 2019

The Dhaka megacity is highly vulnerable to anthropogenic climate change. In addition to the risks... more The Dhaka megacity is highly vulnerable to anthropogenic climate change. In addition to the risks associated with high population density and unplanned infrastructures, temperature and precipitation changes are two environmental factors which have the greatest potential to negatively impact the residential population, both now and into the future. This study uses historical climate data recorded in the Dhaka area for the 1995-2014 period, as well as a multi-model dataset, to understand existing climate variability and possible future climate change scenarios. Future climate scenarios and predictions for this area have been carried out with CMIP5 40 GCMs using the three new representative concentration pathways (RCP 4.5, RCP 6.0 and RCP 8.5) adopted by the IPCC. Climate model projections suggest that the average temperature would increase approximately 2.56 °C by the end of the twenty-first century and future monsoonal rainfall events would also substantially increase in frequency, particularly in the month of July. The results indicate that the long, hot and humid (pre-monsoon) and humid and wet (monsoon) season will persist over Dhaka for an increased length of time. A multi-model ensemble projection clearly showed that the risks associated with the modeled climate change parameters could increase Dhaka's vulnerability to climate change by the end of the twenty-first century. It also indicated that issues associated with waterlogging, public health, transport system, and water supply would impact many areas within the Dhaka megacity. This study provides information, which can be used to assist in the development of measures to support the sustainable growth of Dhaka.

SN Applied Sciences, May 19, 2021

Changes in land cover are a major driving force behind habitat change, which signifcantly impacts... more Changes in land cover are a major driving force behind habitat change, which signifcantly impacts the distribution of wildlife and ecological systems. However, there is a substantial lack of information on the efects of land cover changes on wildlife habitat and local conservation. Therefore, it is essential to understand how land cover changes may threaten future land cover trends and wildlife habitat loss, especially in protected areas. Landsat satellite imagery uses a geographic information system and remote sensing techniques to determine the spatiotemporal pattern of land cover change and its impact on the human–elephant confict in the Fashiakhali Wildlife Sanctuary. We found that within the sanctuary (1994–2005), settlements, agricultural land, and bare land increased by 69.8 ha (2.3%), 991.6ha (32.3%), and 39.5ha (1.3%), and forest areas and water areas decreased by 1094.1 ha (35.7%) and 6.9ha (0.2%), respectively. On the other hand (2005–2015), settlements, agricultural land, and water areas increased by 11.7ha (0.4%), 264.7ha (8.6%), and 36.2ha (1.2%), and forest areas and bare land decreased by 308.9 ha (10.1%) and 3.7ha (0.1%), respectively. Our fndings have shown that increased agriculture and settlements have become a severe threat to the ecological sustainability of elephant habitat, resulting in habitat fragmentation and human encroachment of elephant habitats, as well as extreme pressure and competition on resources.

Background: Visceral leishmaniasis is a considerable public health burden on the Indian subcontin... more Background: Visceral leishmaniasis is a considerable public health burden on the Indian subcontinent. The disease
is highly endemic in the north-central part of Bangladesh, affecting the poorest and most marginalized communities.
Despite the fact that visceral leishmaniasis (VL) results in mortality, severe morbidity, and socioeconomic stress in the
region, the spatiotemporal dynamics of the disease have largely remained unexplored, especially in Bangladesh.
Methods: Monthly VL cases between 2010 and 2014, obtained from subdistrict hospitals, were studied in this work.
Both global and local spatial autocorrelation techniques were used to identify spatial heterogeneity of the disease. In
addition, a spatial scan test was used to identify statistically significant space-time clusters in endemic locations of
Bangladesh.
Results: Global and local spatial autocorrelation indicated that the distribution of VL was spatially autocorrelated,
exhibiting both contiguous and relocation-type of diffusion; however, the former was the main type of VL spread
in the study area. The spatial scan test revealed that the disease had ten times higher incidence rate within the
clusters than in non-cluster zones. Both tests identified clusters in the same geographic areas, despite the differences in
their algorithm and cluster detection approach.
Conclusion: The cluster maps, generated in this work, can be used by public health officials to prioritize areas for
intervention. Additionally, initiatives to control VL can be handled more efficiently when areas of high risk of the
disease are known. Because global environmental change is expected to shift the current distribution of vectors
to new locations, the results of this work can help to identify potentially exposed populations so that adaptation
strategies can be formulated.
Keywords: Visceral leishmaniasis, Spatial heterogeneity, Geographic information system, Bangladesh

The use of spectral vegetation index, namely the Normalized Difference Vegetation Index (NDVI) wa... more The use of spectral vegetation index, namely the Normalized Difference Vegetation Index (NDVI) was applied to detect areas of vegetation cover and Delta Cue was applied to detect areas of vegetation change. The study then reveals that vegetation cover of the area has changed significantly during 1989 to 2010. In this research attempt has been taken to detect the loss of vegetation cover, to determine the trend, nature, rate, location and magnitude of vegetation and subsequent vegetation change detection for the Patuakhali District using multi-temporal, multi-date and multi-sensor aerospace data. Landsat imageries of the have been used to find out the difference of vegetation coverage with afforestation and deforestation of Patuakhali District over 20 years. Temporal mapping is driven by remote sensing and Geographic Information System (GIS) to capture and analyze information from modern records. The map and the database have been focused the intense changes to the landscape that have incrementally developed over time.

The Ganga/Ganges 1 is an important river system in South Asia which supports the life and livelih... more The Ganga/Ganges 1 is an important river system in South Asia which supports the life and livelihoods of millions of people both in India and Bangladesh. The system has a number of names throughout its length. Below its con-fluence with the Brahmaputra at Aricha it is known as the Padma, which in turn merges with the Upper Meghna at Chandpur below which the channel is known as the Lower Meghna. There is a growing concern about this large river system because its channels are subject to frequent migration, threatening engineering structures and resulting in various environmental and social consequences which may be compounded by climatic variability, land use change, and agricultural intensification as the basin experiences rapid population growth. Concerns have been expressed that the construction of a barrage just upstream of the Indo–Bangladesh border has adversely affected the Ganges reach in Bangladesh. Partly in order to investigate this, the planform changes of the Ganges and the Padma within Bangladesh was analysed over the period 1973 to 2011 using multitemporal Landsat images and long–term flow data in eight epochs with an average duration of 4.5 years. The Padma reach is less affected by the barrage and provides a useful control study. Areas of erosion and deposition were determined from sequential changes in the bankline positions. Mean channel width, sinuosity and braiding index were analysed using a Geographic Information System (GIS). Flood frequency, duration and magnitudes were studied using long-term discharge records. Generally, channel planform evaluation indicated that both the Gan-ges and the Padma experienced contraction, expansion and readjustment in configuration over the last 38 years. Erosion and deposition statistics of the Ganges indicate that 57 km 2 of land was lost along the right bank whereas around 59 km 2 has been gained along the left bank during the assessment period, suggesting that the erosion and accretion of both banks is roughly balanced with a general movement towards the right bank. The width of the Ganges varied from a maximum of 5.36 to a minimum of 3.23 km during the observation period. Changes to sandbar area are, in general, much more radical than changes to the overall width and area of the channel. Measurement of areas of erosion and accretion showed that both banks of the Padma experienced considerable loss of land. The total net loss for left bank and right bank was 155 and 28 km 2 , respectively. The Padma is approximately twice the width of the Ganges and the changes to its channel area are not as temporally dynamic as the Ganges. The relationship between bank curvature and erosion/accretion of the river banks for both rivers was analysed and the results contradict established meander theory. Regression analysis between bank erosion rates, annual average discharge and mean flood flow data showed that bank erosion was significantly correlated with annual average discharge for the Padma (r 2 = 0.6283) and that the Ganges bank erosion rate is influenced by mean flood flow (r 2 = 0.6738). The flood frequency shows generally good stability across the first eight of the nine epochs for the Ganges but for the Padma the frequency showed even greater stability. We were unable to support the widely held belief that the upstream barrage has a deleterious effect on the Ganges but note that there is a slight effect due to the periodic release of sediment through scour sluices.

A database of lightning-related deaths and injuries in Bangladesh was developed from 1990 to mid-... more A database of lightning-related deaths and injuries in Bangladesh was developed from 1990 to mid-2016 from a variety of sources that contains a total of 5,468 casualties, comprised of 3,086 fatalities and 2,382 injuries. Spatial, temporal, and demographic aspects of these lightning casualties are evaluated in order to aid relevant entities in effective management of lightning-related meteorological hazards. The annual averages for Bangladesh are 114 fatalities and 89 injuries over the entire period. Weighting by population reveals a fatality rate of 0.92 per million people per year and an injury rate of 0.71. In contrast, the latest six years have a fatality rate of 1.6 and injury rate of 1.4. The rural portion of lightning fatalities is 93%. Most fatalities occurred between early morning (0600 LST) and early evening (2000). Through the year, more fatalities occur during the pre-monsoon season of March through May than during the monsoon season (June – September). The inter-annual time series of fatalities indicates an increase since the late 2000s which is a result of greatly improved communications leading to better media reporting of lightning casualties. Bangladesh has also become much more populous in recent years. As a result, the most recent six years have 251 fatalities per year that may be considered as the current estimate. The majority of lightning-related deaths occurred to males. Farming is the major activity at the time of lightning fatalities, followed by being inside a dwelling, and returning home or walking around homesteads/courtyards.

Background: Visceral leishmaniasis (VL) is a parasitic infection (also called kala-azar in South ... more Background: Visceral leishmaniasis (VL) is a parasitic infection (also called kala-azar in South Asia) caused by Leishmania donovani that is a considerable threat to public health in the Indian subcontinent, including densely populated Bangladesh. The disease seriously affects the poorest subset of the population in the subcontinent. Despite the fact that the incidence of VL results in significant morbidity and mortality, its environmental determinants are relatively poorly understood, especially in Bangladesh. In this study, we have extracted a number of environmental variables obtained from a range of sources, along with human VL cases collected through several field visits, to model the distribution of disease which may then be used as a surrogate for determining the distribution of Phlebotomus argentipes vector, in hyperendemic and endemic areas of Mymensingh and Gazipur districts in Bangladesh. The analysis was carried out within an ecological niche model (ENM) framework using a maxent to explore the ecological requirements of the disease. Results: The results suggest that VL in the study area can be predicted by precipitation during the warmest quarter of the year, land surface temperature (LST), and normalized difference water index (NDWI). As P. argentipes is the single proven vector of L. donovani in the study area, its distribution could reasonably be determined by the same environmental variables. The analysis further showed that the majority of VL cases were located in mauzas where the estimated probability of the disease occurrence was high. This may reflect the potential distribution of the disease and consequently P. argentipes in the study area. Conclusions: The results of this study are expected to have important implications, particularly in vector control strategies and management of risk associated with this disease. Public health officials can use the results to prioritize their visits in specific areas. Further, the findings can be used as a baseline to model how the distribution of the disease caused by P. argentipes might change in the event of climatic and environmental changes that resulted from increased anthropogenic activities in Bangladesh and elsewhere.

American Association of Geographer (Annual Meeting, New Orleans 2018), 2018

American Meteorological Society, 2017

Springer International Publishing, 2017

Kala Azar in South Asia, 2016

Earth Systems and Environment, 2019

International Journal of Climatology, 2017

Theoretical and Applied Climatology, 2017

Earth Systems and Environment, 2019

SN Applied Sciences, May 19, 2021

The use of spectral vegetation index, namely the Normalized Difference Vegetation Index (NDVI) wa... more The use of spectral vegetation index, namely the Normalized Difference Vegetation Index (NDVI) was applied to detect areas of vegetation cover and Delta Cue was applied to detect areas of vegetation change. The study then reveals that vegetation cover of the area has changed significantly during 1989 to 2010. In this research attempt has been taken to detect the loss of vegetation cover, to determine the trend, nature, rate, location and magnitude of vegetation and subsequent vegetation change detection for the Patuakhali District using multi-temporal, multi-date and multi-sensor aerospace data. Landsat imageries of the have been used to find out the difference of vegetation coverage with afforestation and deforestation of Patuakhali District over 20 years. Temporal mapping is driven by remote sensing and Geographic Information System (GIS) to capture and analyze information from modern records. The map and the database have been focused the intense changes to the landscape that have incrementally developed over time.