Browsing by Author "Shahid, Shamsuddin"

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Assessing Seismicity in Bangladesh: An Application of Guttenberg-Richter Relationship and Spectral Analysis
(Taylor & Francis Group, 2023-08-21) Islam, Abu Reza Md. Towfiqul; Akter, Mst. Yeasmin; Amanat, Sumaia; Alam, Edris; Sultana, Mst. Laila; Shahid, Shamsuddin; Das, Arnob; Peu, Susmita Datta; Mallick, Javed
Bangladesh has a high risk of earthquakes because the Dauki, Jamuna, and Chittagong-Myanmar faults are still active. However, the assessment of seismicity remains a big challenge due to the complex geologic setting of Bangladesh. This study employed the Guttenberg-Richter relationship and the spectral models to assess and analyze the earthquake conditions in Bangladesh. Besides, an instrumental earthquake catalogue, obtained from the Bangladesh Meteorological Department (BMD), covering 1985–2017, is established. The results revealed that the Guttenberg-Richter constants of a and b were 2.981 and 0.392, which propagated a strain release from 1992 to 2017. The spectral model analyses, e.g. wavelet transform (WT), short-time Fourier transformation (STFT), and multitaper model (MTM), demonstrated the magnitude and strain release anomalies of the same magnitude ranging from 4.8 to 5.7, indicating the probable precursor of an upcoming earthquake. Notably, magnitudes have been running around 4.5–5.8, which may act as a signal to major earthquakes that have not been evident before. The proposed models allowed for the completion of the Bangladesh earthquake catalogue and provided a platform for future seismicity assessment and earthquake probability analysis. These results should be considered in determining how likely earthquakes are to happen in an area or region.
Climate Change and It's Impact on Ground Water Resources in Northwest Bangladesh
(University of Rajshahi, 2011) Rahman, Md. Moshiur; Keramat, Mumnunul; Shahid, Shamsuddin
Northwest region of Bangladesh is one of the most water stressed region of the country. All the rivers and cannels of the area dry up during the dry season and make the people completely dependent on groundwater. Cultivation of dry season rice which is the lifeline of the livelihood in the most part of the region completely relies of groundwater supply. Scarcity of groundwater for irrigation during the recent years has hampered the agricultural production in the area. Prolonged absence of groundwater within the operating range of shallow tube-wells during the dry season is a growing concern in the area. It is anticipated that climate change will aggravate the situation in near future. A study has been carried out in the present research to identify the causes of groundwater scarcity, estimate the groundwater demand, project the future climate, and to assess the impacts of climate change on groundwater scarcity in the northwest districts of Bangladesh. Long-term groundwater hydrographs are analyzed and correlated with standardized precipitation index to identify the probable causes of groundwater scarcity in the region. Climate models are run with IPCC B2 SRES scenario to project the future change of climate in the region. The projected climatic parameters are then used to estimate the change in irrigation demand in the context of climate change. Finally, the impacts of changing irrigation demand on groundwater level are assessed. The study revealed that recurrent droughts, rapid expansion of groundwater based irrigation and cross-boundary anthropogenic interventions are the main causes of groundwater scarcity in the area. The climate models project an average increase of temperature and rainfall in the region. This will cause an increase of water requirement for land preparation, evapotranspiration and effective precipitation during irrigation period. However, there will be no appreciable change in overall irrigation water requirement as the irrigation period will be substantially shortened by the increased temperature. The study revealed that the climate change will cause an increase in daily use of water for irrigation in the end of this century. As groundwater is the main source of irrigation, higher abstraction rate of groundwater for irrigation will cause a negative impact on groundwater level which in turn will negatively affect the prevailing situation of groundwater scarcity in the area during the dry season.
Contamination and Ecological Risk Assessment of CR, As, CD and PB in Water and Sediment of the Southeastern Bay of Bengal Coast in a Developing Country
(Elsevier, 2023-12-15) Islam, Md. Saiful; Islam, Md. Towhidul; Antu, Uttam Biswas; Saikat, Md. Sadik Mahmud; Ismail, Zulhilmi; Shahid, Shamsuddin; Islam, Abu Reza Md. Towfiqul; Ali, Mir Mohammad; Al Bakky, Abdullah; Ahmed, Sujat; Ibrahim, Khalid A.; Al-Qthanin, Rahmah N.; Idris, Abubakr M.
Safe levels of heavy metals in the surface water and sediment of the eastern Bay of Bengal coast have not been universally established. Current study characterized heavy metals such as arsenic (As), chromium (Cr), cadmium (Cd) and lead (Pb) in surface water and sediments of the most important fishing resource at the eastern Bay of Bengal coast, Bangladesh. Both water and sediment samples were analyzed using inductively coupled plasma mass spectrometer. Considering both of the seasons, the mean concentrations of Cr, As, Cd, and Pb in water samples were 33.25, 8.14, 0.48, and 21.14 μg/L, respectively and in sediment were 30.47, 4.48, 0.20, and 19.98 mg/kg, respectively. Heavy metals concentration in water samples surpassed the acceptable limits of usable water quality, indicating that water from this water resource is not safe for drinking, cooking, bathing, and any other uses. Enrichment factors also directed minor enrichment of heavy metals in sediment of the coast. Other indexes for ecological risk assessment such as pollution load index (PLI), contamination factor (CF), geoaccumulation index (Igeo), modified contamination degree (mCd), and potential ecological risk index (PERI) also indicated that sediment of the coastal watershed was low contamination. In-depth inventorying of heavy metals in both water and sediment of the study area are required to determine ecosystem health for holistic risk assessment and management.
Modulation of coupling climatic extremes and their climate signals in a subtropical monsoon country
(2024-03-09) Md. Towfiqul Islam, Abu Reza; Akter, Mst. Yeasmin; Abdul Fattah, Md.; Mallick, Javed; Parvin, Ishita; Touhidul Islam, H. M.; Shahid, Shamsuddin; Kabir, Zobaidul; Kamruzzaman, Mohammad
The interaction between extreme precipitation and temperature events has significant implications for society, the economy, and the ecosystem. While numerous studies have explored changes in precipitation and temperature extremes in subtropical monsoon country, there is a dearth of knowledge regarding the coupling of these extremes, particularly the simultaneous occurrence of extreme events. To bridge this research gap, our study aims to investigate the modulation of coupling climatic extremes, their climate signals in subtropical monsoon country, and the underlying causes of changes. To accomplish this, we utilized monthly precipitation and temperature datasets from 20 sites across Bangladesh, along with two climate signal indices, covering the period from 1980 to 2017. We employed four indices, namely consecutive dry days (CDD), consecutive wet days (CWD), minimum daily temperature (TNn), and maximum daily temperature (TXx), to assess temperature and precipitation modulation patterns. Our findings indicate a positive trend in temperature indices, with warm days and nights exhibiting a more rapid increase compared to cool days and nights in Bangladesh. Analysis of precipitation indices reveals a mixed pattern of changes, with an increase in CWD and a decrease in CDD. However, when examining specific regions, we observe an increasing trend in monsoon CDD in the northwest and coastal districts, suggesting a shift towards drier conditions. Conversely, a declining trend in winter CDD in the southeast and northwest indicates a shift towards wetter conditions. Comparing coupled precipitation and temperature extremes between 1999 and 2017 and 1980–1998 reveals a broader impact of these extremes in recent decades. Detrended fluctuation analysis further suggests that the current trend in extremes is likely to persist in the future. Our study also establishes a relationship between the El Niño-Southern Oscillation (ENSO) and climate extremes in Bangladesh, albeit with modulations in cycles. Overall, a combination of elevated summer geopotential height, the absence of a visible anticyclonic center, reduced high cloud cover, and enhanced low cloud covers collectively contribute to increased frequency and intensity of warm extremes in subtropical country.
Temperature extremes Projections over Bangladesh from CMIP6 Multi-model Ensemble
(Scopus, 2024-08-31) Akter, Mst Yeasmin; Islam, Abu Reza Md Towfiqul; Mallick, Javed; Alam, Md Mahfuz; Alam, Edris; Shahid, Shamsuddin; Biswas, Jatish Chandra; Alam, GM Manirul; Pal, Subodh Chandra; Oliver, Md Moinul Hosain
Bangladesh, a sub-tropical monsoon climate with low-lying areas, is very susceptible to the impacts of climate change. However, there has been a shortage of studies about the periodicity and projected changes in extreme temperature in this area, which is a crucial part of adapting to climate change. A study employed a multimodal ensemble (MME) mean of 13 bias-corrected CMIP6 GCMs to fill this knowledge gap. The purpose of this study was to project changes in 8 extreme temperature indices (ETIs) across Bangladesh for the near future (2021–2060) and far future (2061–2100) under two different Shared Socioeconomic Pathways (SSPs): medium (SSP2-4.5) and high (SSP5-8.5) scenarios. The research analyzed the average spatiotemporal changes by considering the reference period from 1995 to 2014 for each indicator in future periods. The results indicate that Bangladesh is projected to see a rise in average annual temperature in the 21st century, aligning with the global average. Warm days (TX90p) and nights (TN90p) were projected to increase, while cold days (TX10p) and nights (TN10p) were expected to decrease across the country for both the near (2021–2060) and far future (2061–2100). The projected highest increase in TX90p and TN90p was 6.90 days/decade in the northeast, and the highest decrease in TX10p and TN10p was 6.22 days/decade in the southwest. The study revealed a higher rise in TN90p than TX90p, indicating a faster decline in cold extremes than a rise in hot extremes. The rising temperature would cause an increase in the spell duration index (WSDI) and growing degree day (GDD) by 5–6 and 6–7 days/decade, respectively. Therefore, immediate measures must be taken to mitigate the detrimental effects of extreme temperatures, leading to heat stress. To reduce the effects on agriculture, ecosystems, human health, and biodiversity, policymakers and stakeholders must understand these anticipated changes and adopt appropriate actions.
Temperature extremes Projections over Bangladesh from CMIP6 Multi-model Ensemble
(Springer Nature, 2024-08-24) Akter, Mst Yeasmin; Islam, Abu Reza Md Towfiqul; Mallick, Javed; Alam, Md Mahfuz; Alam, Edris; Shahid, Shamsuddin; Biswas, Jatish Chandra; Alam, GM Manirul; Pal, Subodh Chandra; Oliver, Md Moinul Hosain
Bangladesh, a sub-tropical monsoon climate with low-lying areas, is very susceptible to the impacts of climate change. However, there has been a shortage of studies about the periodicity and projected changes in extreme temperature in this area, which is a crucial part of adapting to climate change. A study employed a multimodal ensemble (MME) mean of 13 bias-corrected CMIP6 GCMs to fill this knowledge gap. The purpose of this study was to project changes in 8 extreme temperature indices (ETIs) across Bangladesh for the near future (2021–2060) and far future (2061–2100) under two different Shared Socioeconomic Pathways (SSPs): medium (SSP2-4.5) and high (SSP5-8.5) scenarios. The research analyzed the average spatiotemporal changes by considering the reference period from 1995 to 2014 for each indicator in future periods. The results indicate that Bangladesh is projected to see a rise in average annual temperature in the 21st century, aligning with the global average. Warm days (TX90p) and nights (TN90p) were projected to increase, while cold days (TX10p) and nights (TN10p) were expected to decrease across the country for both the near (2021–2060) and far future (2061–2100). The projected highest increase in TX90p and TN90p was 6.90 days/decade in the northeast, and the highest decrease in TX10p and TN10p was 6.22 days/decade in the southwest. The study revealed a higher rise in TN90p than TX90p, indicating a faster decline in cold extremes than a rise in hot extremes. The rising temperature would cause an increase in the spell duration index (WSDI) and growing degree day (GDD) by 5–6 and 6–7 days/decade, respectively. Therefore, immediate measures must be taken to mitigate the detrimental effects of extreme temperatures, leading to heat stress. To reduce the effects on agriculture, ecosystems, human health, and biodiversity, policymakers and stakeholders must understand these anticipated changes and adopt appropriate actions.
Temperature Extremes Projections Over Bangladesh From Cmip6 Multi-model Ensemble
(Springer Nature, 2024-08-31) Akter, Mst Yeasmin; Islam, Abu Reza Md Towfiqul; Mallick, Javed; Alam, Md Mahfuz; Alam, Edris; Shahid, Shamsuddin; Biswas, Jatish Chandra; Alam, GM Manirul; Pal, Subodh Chandra; Oliver, Md Moinul Hosain
Bangladesh, a sub-tropical monsoon climate with low-lying areas, is very susceptible to the impacts of climate change. However, there has been a shortage of studies about the periodicity and projected changes in extreme temperature in this area, which is a crucial part of adapting to climate change. A study employed a multimodal ensemble (MME) mean of 13 bias-corrected CMIP6 GCMs to fill this knowledge gap. The purpose of this study was to project changes in 8 extreme temperature indices (ETIs) across Bangladesh for the near future (2021–2060) and far future (2061–2100) under two different Shared Socioeconomic Pathways (SSPs): medium (SSP2-4.5) and high (SSP5-8.5) scenarios. The research analyzed the average spatiotemporal changes by considering the reference period from 1995 to 2014 for each indicator in future periods. The results indicate that Bangladesh is projected to see a rise in average annual temperature in the 21st century, aligning with the global average. Warm days (TX90p) and nights (TN90p) were projected to increase, while cold days (TX10p) and nights (TN10p) were expected to decrease across the country for both the near (2021–2060) and far future (2061–2100). The projected highest increase in TX90p and TN90p was 6.90 days/decade in the northeast, and the highest decrease in TX10p and TN10p was 6.22 days/decade in the southwest. The study revealed a higher rise in TN90p than TX90p, indicating a faster decline in cold extremes than a rise in hot extremes. The rising temperature would cause an increase in the spell duration index (WSDI) and growing degree day (GDD) by 5–6 and 6–7 days/decade, respectively. Therefore, immediate measures must be taken to mitigate the detrimental effects of extreme temperatures, leading to heat stress. To reduce the effects on agriculture, ecosystems, human health, and biodiversity, policymakers and stakeholders must understand these anticipated changes and adopt appropriate actions.
The impact of cyclone aila on the sundarban forest ecosystem
(© 2017 CESER Publications, 2017) Rahman, Shafiqur M.A.; Rahman, Hafizur Z.; Shahid, Shamsuddin; Khan, Rehanullah; Jahan, Nusrat A.; Ahmed, Zafar U.; Khanum, R.; Ahmed, Manzoor F.; Mohsenipour, Morteza
Climate change is expected to increase stress on mangrove forests across the globe in multiple pathways. Changes in sea level, temperature, tropical cyclones, saline water invasion, land inundation, ocean acidification, invasive species due to climate change. Livelihoods of above hundred million people depending on mangrove forest ecosystem services, mostly living in developing countries will be severely affected due to climate change. The impacts of recently occurred tropical cyclone Aila (May 25, 2009) on Sundarban mangrove forest ecosystem in Bangladesh has been assessed in this research in order to understand the possible impacts of climate change induced extreme weather events on forest ecosystem services. Time series of satellite images, socio-economic census data, focus group discussions (FGD) outcomes, and other ancillary information have been analyzed for this purpose. The study revealed that cyclone Aila caused incremental stresses on the socioeconomic conditions of coastal communities through rendering huge areas of land unproductive for a long time, and in some cases forever. People who were dependent on land resources for their livelihoods were forced to change their livelihood on forest resources, which in turn caused increased pressure on already stressed forest resources. It is concluded that increasing frequency and severity of climate change induced extreme events will certainly increase pressure on forest ecosystem services, which eventually may pose threat of extinction to biodiversity of Sundarban mangrove forest, if necessary adaptation measures are not taken.