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Changes in the natural climate is a major concern for food security across the world, including Bangladesh. This paper presents results from an analysis on quantitative assessment of changes in rainfall and potential evapotranspiration (PET) in the northwest region of Bangladesh, which is a major agricultural hub in the country. The study was conducted using results from 28 global climate models (GCMs), based on IPCC’s 5th assessment report (AR5) for two emission scenarios. Projections were made over the period of 2045 to 2075 for 16 administrative districts in the study area, and the changes were estimated at annual, seasonal and monthly time scale. More projections result in an increase in rainfall than decrease, while almost all projections show an increase in PET. Although annual rainfall is generally projected to increase, some projections show a decrease in some months, especially in December and January. Across the region, the average change projected by the 28 GCMs for the moderate emission was an increase of 235 mm (12.4%) and 44 mm (3.4%) for rainfall and PET, respectively. Increases in rainfall and PET are slightly higher (0.6% and 0.2%, respectively) under high emission scenarios. Increases in both rainfall and PET were projected for two major cropping seasons, Kharif (May-Oct) and Rabi (Nov-Apr). Projections of rainfall show increase in the range of 160 to 250 mm (with an average of 200 mm) during the Kharif season. Although an increase is projected in the Rabi season, the amount is very small (~10mm). It is important to note that rainfall increases mostly in the Kharif season, but PET increases for both Kharif and Rabi seasons. Contrary to rainfall, increase in PET is higher during Rabi season. This information is crucial for better adaptation under increased water demand for agricultural and domestic use.
Fazlul Karim; Mohammed Mainuddin; Masud Hasan; Mac Kirby. Assessing the Potential Impacts of Climate Changes on Rainfall and Evapotranspiration in the Northwest Region of Bangladesh. Climate 2020, 8, 94 .
AMA StyleFazlul Karim, Mohammed Mainuddin, Masud Hasan, Mac Kirby. Assessing the Potential Impacts of Climate Changes on Rainfall and Evapotranspiration in the Northwest Region of Bangladesh. Climate. 2020; 8 (8):94.
Chicago/Turabian StyleFazlul Karim; Mohammed Mainuddin; Masud Hasan; Mac Kirby. 2020. "Assessing the Potential Impacts of Climate Changes on Rainfall and Evapotranspiration in the Northwest Region of Bangladesh." Climate 8, no. 8: 94.
Hydrological connectivity between rivers and wetlands is considered one of the key critical factors for the integrity of floodplain landscapes. This study is a comprehensive modelling exercise on quantifying flood-induced wetland connectivity and the potential impacts of climate and water storage in an unregulated river basin in northern Australia. Flood inundation was simulated using a two-dimensional hydrodynamic model and the connectivities between wetlands and rivers were calculated using geoprocessing tools in ArcGIS. Wetlands in the floodplain were identified using waterbody maps derived from satellite imagery. A broadly representative sample of 20 wetlands were selected from 158 wetlands in the Mitchell basin considering location, size and spatial distribution. Five flood events ranging from 1 in 2 to 1 in 100 years were investigated to evaluate how connectivity changes with flood magnitude. Connectivities were assessed for the current condition as well as for two scenarios of future climate (Cwet and Cdry) and one scenario of dam storage. Results showed that a 1 in 100 years event inundated about 5450 km2 of land compared to 1160 km2 for a 1 in 2 years event. Average connectivity of wetlands in the Mitchell basin varies from 1 to 5 days for the floods of 1 in 2 to 1 in 26 years. As expected, a large flood produces longer duration of connectivity relative to a small flood. Results also showed that reduction in mean connectivity under a dryer climate (up to 1.8 days) is higher than the possibility of increase under a wet climate (up to 1 day). The impacts of a water storage, in the headwater catchment, are highly pronounced in terms of inundation and wetland connectivity (e.g., mean connectivity reduced by 1.7 days). The relative change in connectivity is higher for a small flood compared to that of a large event. These results demonstrate that there is a possibility of both increase and decease in connectivity under future climate. However, any water storage will negatively impact the connectivity between floodplain waterbodies and thus reduce the material exchange resulting in a reduction in primary and secondary productions in rivers and wetlands.
Fazlul Karim; Steve Marvanek; Linda E. Merrin; Daryl Nielsen; Justin Hughes; Danial Stratford; Carmel Pollino. Modelling Flood-Induced Wetland Connectivity and Impacts of Climate Change and Dam. Water 2020, 12, 1278 .
AMA StyleFazlul Karim, Steve Marvanek, Linda E. Merrin, Daryl Nielsen, Justin Hughes, Danial Stratford, Carmel Pollino. Modelling Flood-Induced Wetland Connectivity and Impacts of Climate Change and Dam. Water. 2020; 12 (5):1278.
Chicago/Turabian StyleFazlul Karim; Steve Marvanek; Linda E. Merrin; Daryl Nielsen; Justin Hughes; Danial Stratford; Carmel Pollino. 2020. "Modelling Flood-Induced Wetland Connectivity and Impacts of Climate Change and Dam." Water 12, no. 5: 1278.
This paper presents the results from a study on the application of an artificial neural network (ANN) model for regional flood frequency analysis (RFFA). The study was conducted using stream flow data from 88 gauging stations across New South Wales (NSW) in Australia. Five different models consisting of three to eight predictor variables (i.e., annual rainfall, drainage area, fraction forested area, potential evapotranspiration, rainfall intensity, river slope, shape factor and stream density) were tested. The results show that an ANN model with a higher number of predictor variables does not always improve the performance of RFFA models. For example, the model with three predictor variables performs considerably better than the models using a higher number of predictor variables, except for the one which contains all the eight predictor variables. The model with three predictor variables exhibits smaller median relative error values for 2- and 20-year return periods compared to the model containing eight predictor variables. However, for 5-, 10-, 50- and 100-year return periods, the model with eight predictor variables shows smaller median relative error values. The proposed ANN modelling framework can be adapted to other regions in Australia and abroad.
Sasan Kordrostami; Mohammad A Alim; Fazlul Karim; Ataur Rahman. Regional Flood Frequency Analysis Using An Artificial Neural Network Model. Geosciences 2020, 10, 127 .
AMA StyleSasan Kordrostami, Mohammad A Alim, Fazlul Karim, Ataur Rahman. Regional Flood Frequency Analysis Using An Artificial Neural Network Model. Geosciences. 2020; 10 (4):127.
Chicago/Turabian StyleSasan Kordrostami; Mohammad A Alim; Fazlul Karim; Ataur Rahman. 2020. "Regional Flood Frequency Analysis Using An Artificial Neural Network Model." Geosciences 10, no. 4: 127.
Probabilistic models for sub-daily rainfall predictions are important tools for understanding catchment hydrology and estimating essential rainfall inputs for agricultural and ecological studies. This research aimed at achieving theoretical probability distribution to non-zero, sub-daily rainfall using data from 1467 rain gauges across the Australian continent. A framework was developed for estimating rainfall data at ungauged locations using the fitted model parameters from neighbouring gauges. The Lognormal, Gamma and Weibull distributions, as well as their mixed distributions were fitted to non-zero six-minutes rainfall data. The root mean square error was used to evaluate the goodness of fit for each of these distributions. To generate data at ungauged locations, parameters of well-fit models were interpolated from the four closest neighbours using inverse weighting distance method. Results show that the Gamma and Weibull distributions underestimate and lognormal distributions overestimate the high rainfall events. In general, a mixed model of two distributions was found better compared to the results of an individual model. Among the five models studied, the mixed Gamma and Lognormal (G-L) distribution produced the minimum root mean square error. The G-L model produced the best match to observed data for high rainfall events (e.g., 90th, 95th, 99th, 99.9th and 99.99th percentiles).
Masud Hasan; Barry F. W. Croke; Shuangzhe Liu; Kunio Shimizu; Fazlul Karim. Using Mixed Probability Distribution Functions for Modelling Non-Zero Sub-Daily Rainfall in Australia. Geosciences 2020, 10, 43 .
AMA StyleMasud Hasan, Barry F. W. Croke, Shuangzhe Liu, Kunio Shimizu, Fazlul Karim. Using Mixed Probability Distribution Functions for Modelling Non-Zero Sub-Daily Rainfall in Australia. Geosciences. 2020; 10 (2):43.
Chicago/Turabian StyleMasud Hasan; Barry F. W. Croke; Shuangzhe Liu; Kunio Shimizu; Fazlul Karim. 2020. "Using Mixed Probability Distribution Functions for Modelling Non-Zero Sub-Daily Rainfall in Australia." Geosciences 10, no. 2: 43.
Food and water are at the heart of sustainable development. Roof-harvested rainwater kept in rainwater storage systems (RSS) and used in household agriculture (HA) has the potential to increase yields and supplement household nutrition. Combined systems may contribute to at least eight of the United Nations’ 17 Sustainable Development Goals (SDGs). In this paper, a daily analysis tool, ERain, is used to assess what area of vegetables can be reliably irrigated by roof-harvested rainwater. A socio-economic context is built around an orphanage in the semi-humid region of Nakuru, Kenya. Comparisons are made with the semi-arid region of East Pokot. A 225 kL closed masonry tank and a 1 ML open reservoir with an additional 8 kL/day of recycled water entering are analyzed for various roof sizes. The 225 kL RSS connected to 1000 m2 of roof and irrigating 1000 m2 could increase yields from 1850 to 4200 kg/year in Nakuru. If evaporation was controlled, the 1 mL RSS and recycled water system could support 4000 m2 of land, yielding nearly 20,000 kg/year, which is enough to meet the WHO recommended vegetable dietary requirements of the orphanage. A combination of crops, some for consumption and some for sale, could be grown.
Caleb Amos; Ataur Rahman; John Gathenya; Eran Friedler; Fazlul Karim; Andre Renzaho. Roof-Harvested Rainwater Use in Household Agriculture: Contributions to the Sustainable Development Goals. Water 2020, 12, 332 .
AMA StyleCaleb Amos, Ataur Rahman, John Gathenya, Eran Friedler, Fazlul Karim, Andre Renzaho. Roof-Harvested Rainwater Use in Household Agriculture: Contributions to the Sustainable Development Goals. Water. 2020; 12 (2):332.
Chicago/Turabian StyleCaleb Amos; Ataur Rahman; John Gathenya; Eran Friedler; Fazlul Karim; Andre Renzaho. 2020. "Roof-Harvested Rainwater Use in Household Agriculture: Contributions to the Sustainable Development Goals." Water 12, no. 2: 332.
Probabilistic models are useful tools in understanding rainfall characteristics, generating synthetic data and predicting future events. This study describes the results from an analysis on comparing the probabilistic nature of daily, monthly and seasonal rainfall totals using data from 1327 rainfall stations across Australia. The main objective of this research is to develop a relationship between parameters obtained from models fitted to daily, monthly and seasonal rainfall totals. The study also examined the possibility of estimating the parameters for daily data using fitted parameters to monthly rainfall. Three distributions within the Exponential Dispersion Model (EDM) family (Normal, Gamma and Poisson-Gamma) were found to be optimal for modelling the daily, monthly and seasonal rainfall total. Within the EDM family, Poisson-Gamma distributions were found optimal in most cases, whereas the normal distribution was rarely optimal except for the stations from the wet region. Results showed large differences between regional and seasonal ϕ-index values (dispersion parameter), indicating the necessity of fitting separate models for each season. However, strong correlations were found between the parameters of combined data and those derived from individual seasons (0.70–0.81). This indicates the possibility of estimating parameters of individual season from the parameters of combined data. Such relationship has also been noticed for the parameters obtained through monthly and daily models. Findings of this research could be useful in understanding the probabilistic features of daily, monthly and seasonal rainfall and generating daily rainfall from monthly data for rainfall stations elsewhere.
Masud Hasan; Barry F. W. Croke; Fazlul Karim. Spatial and Seasonal Variations and Inter-Relationship in Fitted Model Parameters for Rainfall Totals across Australia at Various Timescales. Climate 2019, 7, 4 .
AMA StyleMasud Hasan, Barry F. W. Croke, Fazlul Karim. Spatial and Seasonal Variations and Inter-Relationship in Fitted Model Parameters for Rainfall Totals across Australia at Various Timescales. Climate. 2019; 7 (1):4.
Chicago/Turabian StyleMasud Hasan; Barry F. W. Croke; Fazlul Karim. 2019. "Spatial and Seasonal Variations and Inter-Relationship in Fitted Model Parameters for Rainfall Totals across Australia at Various Timescales." Climate 7, no. 1: 4.
Understanding the nature of frequent floods is important for characterising channel morphology, riparian and aquatic habitat, and informing river restoration efforts. This paper presents results from an analysis on frequency estimates of low magnitude floods using the annual maximum and partial series data compared to actual flood series. Five frequency distribution models were fitted to data from 24 gauging stations in the Great Barrier Reef (GBR) lagoon catchments in north-eastern Australia. Based on the goodness of fit test, Generalised Extreme Value, Generalised Pareto and Log Pearson Type 3 models were used to estimate flood frequencies across the study region. Results suggest frequency estimates based on a partial series are better, compared to an annual series, for small to medium floods, while both methods produce similar results for large floods. Although both methods converge at a higher recurrence interval, the convergence recurrence interval varies between catchments. Results also suggest frequency estimates vary slightly between two or more partial series, depending on flood threshold, and the differences are large for the catchments that experience less frequent floods. While a partial series produces better frequency estimates, it can underestimate or overestimate the frequency if the flood threshold differs largely compared to bankfull discharge. These results have significant implications in calculating the dependency of floodplain ecosystems on the frequency of flooding and their subsequent management.
Fazlul Karim; Masud Hasan; Steve Marvanek. Evaluating Annual Maximum and Partial Duration Series for Estimating Frequency of Small Magnitude Floods. Water 2017, 9, 481 .
AMA StyleFazlul Karim, Masud Hasan, Steve Marvanek. Evaluating Annual Maximum and Partial Duration Series for Estimating Frequency of Small Magnitude Floods. Water. 2017; 9 (7):481.
Chicago/Turabian StyleFazlul Karim; Masud Hasan; Steve Marvanek. 2017. "Evaluating Annual Maximum and Partial Duration Series for Estimating Frequency of Small Magnitude Floods." Water 9, no. 7: 481.
Surface water connectivity between waterbodies in a river–floodplain system is considered one of the key determinants of habitat quality, biodiversity and ecological integrity. This manuscript presents results from an investigation into the potential changes in floodplain inundation and connectivity between wetlands and rivers under projected future climates, in a large river catchment in Western Australia. The study was conducted using a two-dimensional hydrodynamic model (MIKE 21), and the modelling domain included the floodplain reaches encompassing the ecologically important wetlands. A lumped rainfall–runoff model (SIMHYD) was used to estimate local runoff and inflows from ungauged catchments. A SRTM derived 30-m elevation data was used to parameterize land topography and stream networks in the hydrodynamic model. Hydraulic roughness parameters were estimated using a land cover map, which was developed using a combination of aerial photography, topographic maps and Google Earth imagery. The hydrodynamic model was calibrated using stream gauge data and flood inundation maps derived from Moderate Resolution Imaging Spectroradiometer imagery. Model simulated stage heights were combined with land topography to identify floodplain pathways that connect wetlands with rivers. The connectivity of 30 off-stream wetlands was evaluated under present and future climates. The duration of connection of the individual wetlands to the main river channel varied from 1 to 40 days depending on flood magnitude and duration. Topographic relief, location on the floodplain and magnitude and duration of the flood were found to be key factors governing the level of connectivity, and the relationship between return period of flood and inundated area was found to be non-linear. Modelling under a drier future climate indicated that the duration of connectivity of wetlands could be up to 20% less than under the current climate, whilst under a wetter climate the connectivity could be 5% longer. The results of this study provide potential use for future studies on movement and recruitment patterns of aquatic biota, wetland habitat characteristics and water quality and wetland biodiversity assessment. Copyright © 2015 John Wiley & Sons, Ltd.
Fazlul Karim; Cuan Petheram; Steve Marvanek; Catherine Ticehurst; Jim Wallace; Masud Hasan. Impact of climate change on floodplain inundation and hydrological connectivity between wetlands and rivers in a tropical river catchment. Hydrological Processes 2015, 30, 1574 -1593.
AMA StyleFazlul Karim, Cuan Petheram, Steve Marvanek, Catherine Ticehurst, Jim Wallace, Masud Hasan. Impact of climate change on floodplain inundation and hydrological connectivity between wetlands and rivers in a tropical river catchment. Hydrological Processes. 2015; 30 (10):1574-1593.
Chicago/Turabian StyleFazlul Karim; Cuan Petheram; Steve Marvanek; Catherine Ticehurst; Jim Wallace; Masud Hasan. 2015. "Impact of climate change on floodplain inundation and hydrological connectivity between wetlands and rivers in a tropical river catchment." Hydrological Processes 30, no. 10: 1574-1593.
Fazlul Karim; Dushmanta Dutta; Steve Marvanek; Cuan Petheram; Catherine Ticehurst; Julien Lerat; Shaun Kim; Ang Yang. Assessing the impacts of climate change and dams on floodplain inundation and wetland connectivity in the wet–dry tropics of northern Australia. Journal of Hydrology 2015, 522, 80 -94.
AMA StyleFazlul Karim, Dushmanta Dutta, Steve Marvanek, Cuan Petheram, Catherine Ticehurst, Julien Lerat, Shaun Kim, Ang Yang. Assessing the impacts of climate change and dams on floodplain inundation and wetland connectivity in the wet–dry tropics of northern Australia. Journal of Hydrology. 2015; 522 ():80-94.
Chicago/Turabian StyleFazlul Karim; Dushmanta Dutta; Steve Marvanek; Cuan Petheram; Catherine Ticehurst; Julien Lerat; Shaun Kim; Ang Yang. 2015. "Assessing the impacts of climate change and dams on floodplain inundation and wetland connectivity in the wet–dry tropics of northern Australia." Journal of Hydrology 522, no. : 80-94.
The ecological condition and biodiversity values of floodplain wetlands are highly dependent on the hydrological connectivity of wetlands to adjacent rivers. This paper describes a method for quantifying connectivity between floodplain wetlands and the main rivers in a wet tropical catchment of northern Australia. We used a one-dimensional hydrodynamic model to simulate time-varying water depths across the stream network (i.e. rivers, streams and man-made drains). The timing and duration of connectivity of seven wetlands (four natural and three artificial) with the two main rivers in the catchment were then calculated for different hydrological conditions. Location and areal extent of the wetlands and the stream network were identified using high-resolution laser altimetry, and these data formed key inputs to the hydrodynamic model. The model was calibrated using measured water depths and discharges across the floodplain. An algorithm was developed to identify contiguous water bodies at daily time steps, and this gave the temporal history of connection and disconnection between wetlands and the rivers. Simulation results show that connectivity of individual wetlands to both rivers varies from 26 to 365 days during an average hydrological condition. Location, especially proximity to a main river, and wetland type (natural stream or artificial drain) were identified as key factors influencing these levels of connectivity. Some natural wetlands maintain connection with the river for most or all of the year, whereas the connectivity of some artificial wetlands varies from 26 to 36 days according to their patterns of network connection to adjacent rivers - a result that has important implications for the accessibility of these types of wetland to aquatic biota. Using readily available river gauge data, we also show how connectivity modelling can be used to identify periods when connectivity has fallen below critical thresholds for fish movement. These connectivity patterns within the floodplain network are central to the setting of river flows that will meet environmental requirements for biota that use floodplain wetlands during their life history. Copyright 頲013 John Wiley & Sons, Ltd.No Full Tex
Fazlul Karim; Anne Kinsey-Henderson; Jim Wallace; Paul Godfrey; Angela Arthington; Richard Pearson. Modelling hydrological connectivity of tropical floodplain wetlands via a combined natural and artificial stream network. Hydrological Processes 2013, 28, 5696 -5710.
AMA StyleFazlul Karim, Anne Kinsey-Henderson, Jim Wallace, Paul Godfrey, Angela Arthington, Richard Pearson. Modelling hydrological connectivity of tropical floodplain wetlands via a combined natural and artificial stream network. Hydrological Processes. 2013; 28 (23):5696-5710.
Chicago/Turabian StyleFazlul Karim; Anne Kinsey-Henderson; Jim Wallace; Paul Godfrey; Angela Arthington; Richard Pearson. 2013. "Modelling hydrological connectivity of tropical floodplain wetlands via a combined natural and artificial stream network." Hydrological Processes 28, no. 23: 5696-5710.
Much of the sediment and nutrient load to the Great Barrier Reef (GBR) lagoon happens during over bank floods, when discharge can be significantly underestimated by standard river gauges. This paper assesses the potential need for a flood load correction for 28 coastal rivers that discharge into the GBR lagoon. For each river, daily discharge was divided into flows above and below a 'flood' threshold to calculate the mean annual percentage flow above this threshold. Most GBR rivers potentially need a flood load correction as over 15% of their mean annual flow occurs above the minor flood level; only seven rivers need little/no correction as their flood flows were less than 5% of the mean annual flow. Improved assessment of the true load of materials to the GBR lagoon would be an important contribution to the monitoring and reporting of progress towards Reef Plan and associated marine load targets.
Jim Wallace; Fazlul Karim; Scott Wilkinson. Assessing the potential underestimation of sediment and nutrient loads to the Great Barrier Reef lagoon during floods. Marine Pollution Bulletin 2012, 65, 194 -202.
AMA StyleJim Wallace, Fazlul Karim, Scott Wilkinson. Assessing the potential underestimation of sediment and nutrient loads to the Great Barrier Reef lagoon during floods. Marine Pollution Bulletin. 2012; 65 (4-9):194-202.
Chicago/Turabian StyleJim Wallace; Fazlul Karim; Scott Wilkinson. 2012. "Assessing the potential underestimation of sediment and nutrient loads to the Great Barrier Reef lagoon during floods." Marine Pollution Bulletin 65, no. 4-9: 194-202.
Hydrological connectivity between floodplain wetlands and rivers is one of the principal driving mechanisms for the diversity, productivity and interactions of the major biota in river–floodplain systems. This article describes a method of quantifying flood‐induced overbank connectivity using a hydrodynamic model (MIKE 21) to calculate the timing, the duration and the spatial extent of the connections between several floodplain wetlands and rivers in the Tully–Murray catchment, north Queensland, Australia. Areal photogrammetry and field surveyed stream cross data were used to reproduce floodplain topography and rivers in the model. Laser altimetry (LiDAR)–derived fine resolution elevation data, for the central floodplain, were added to the topography model to improve the resolution of key features including wetlands, flow pathways and natural and artificial flow barriers. The hydrodynamic model was calibrated using a combination of in‐stream and floodplain gauge records. A range of off‐stream wetlands including natural and artificial, small and large were investigated for their connectivity with two main rivers (Tully and Murray) flowing over the floodplain for flood events of 1‐, 20‐ and 50‐year recurrence intervals. The duration of the connection of individual wetlands varied from 1 to 12 days, depending on flood magnitude and location in the floodplain, with some wetlands only connected during large floods. All of the wetlands studied were connected to the Tully River for shorter periods than they were to the Murray River because of the higher bank heights and levees on the Tully River and wetland proximity to the Murray River. Other than hydrology, land relief, riverbank elevation and levee banks along the river were found key factors controlling the degree of connectivity. These variations in wetland connectivity could have important implications for aquatic biota that move between rivers and off‐stream habitats during floods. Copyright © 2011 John Wiley & Sons, Ltd.
Fazlul Karim; Anne Kinsey-Henderson; Jim Wallace; Angela Arthington; Richard Pearson. Modelling wetland connectivity during overbank flooding in a tropical floodplain in north Queensland, Australia. Hydrological Processes 2011, 26, 2710 -2723.
AMA StyleFazlul Karim, Anne Kinsey-Henderson, Jim Wallace, Angela Arthington, Richard Pearson. Modelling wetland connectivity during overbank flooding in a tropical floodplain in north Queensland, Australia. Hydrological Processes. 2011; 26 (18):2710-2723.
Chicago/Turabian StyleFazlul Karim; Anne Kinsey-Henderson; Jim Wallace; Angela Arthington; Richard Pearson. 2011. "Modelling wetland connectivity during overbank flooding in a tropical floodplain in north Queensland, Australia." Hydrological Processes 26, no. 18: 2710-2723.
This paper represents the results of wave transformation in porous structures and hydraulic performance of a vertical porous seawall. The study was carried out using a VOF based two-phase numerical hydrodynamic model. The model was developed by coupling an ordinary porous flow model based on extended Navier–Stokes equations for porous media, and a two-phase flow model. A unique solution domain was established with proper treatment of the interface boundary between water, air and the structure. The VOF method with an improved fluid advection algorithm was used to trace the interface between water and air. The resistance to flow caused by the presence of structural material was modeled in terms of drag and inertia forces. The parameters that govern resistance to flow in a porous media were calibrated for a typical structural setup and then the computational efficacy of the model was evaluated for several wave and structural conditions other than the calibrated setup. A set of comparisons of wave properties in and around the structure showed that the model reproduced reasonably good agreement between computed results and measured data. The model was then applied to investigate wave transformation in a vertical porous structure. The role of porosity and width of a structure in reducing wave reflection and increasing energy dissipation was investigated. It is confirmed that there exists an optimum value of structure width and porosity that can maximize hydraulic performances of a porous seawall.
Mohammed Fazlul Karim; Katsutoshi Tanimoto; Phung Dang Hieu. Modelling and simulation of wave transformation in porous structures using VOF based two-phase flow model. Applied Mathematical Modelling 2009, 33, 343 -360.
AMA StyleMohammed Fazlul Karim, Katsutoshi Tanimoto, Phung Dang Hieu. Modelling and simulation of wave transformation in porous structures using VOF based two-phase flow model. Applied Mathematical Modelling. 2009; 33 (1):343-360.
Chicago/Turabian StyleMohammed Fazlul Karim; Katsutoshi Tanimoto; Phung Dang Hieu. 2009. "Modelling and simulation of wave transformation in porous structures using VOF based two-phase flow model." Applied Mathematical Modelling 33, no. 1: 343-360.
This paper describes the impacts of sea surface temperature (SST) rise and sea-level rise (SLR) on cyclonic storm surge flooding in western Bangladesh. A calibrated numerical hydrodynamic model was used to simulate surge wave propagation through the rivers and overland flooding. The model was calibrated with base condition (present climate), and then eight flooding scenarios of plausible future conditions were assessed by considering increased surge heights. Flooded area, flooding depth and surge intrusion length were computed by superimposing the predicted maximum water level information on a digital elevation model (DEM). This analysis showed that for a storm surge under 2 °C SST rise and 0.3 m SLR, flood risk area would be 15.3% greater than the present risk area and depth of flooding would increase by as much as 22.7% within 20 km from the coastline. Within the risk area, the study identified 5690 km2 land (22% of exposed coast) as a high-risk zone (HRZ) where flooding of depth 1 m or more might occur, and people should move to nearby cyclone shelters during extreme cyclonic events. Predicted area of HRZ is 1.26 times the currently demarcated HRZ. It was estimated that 320 additional shelters are required to accommodate people in the newly identified HRZ. This information would be of value to policy and decision makers for future shelter planning and designing shelter heights.
M Karim; N Mimura. Impacts of climate change and sea-level rise on cyclonic storm surge floods in Bangladesh. Global Environmental Change 2008, 18, 490 -500.
AMA StyleM Karim, N Mimura. Impacts of climate change and sea-level rise on cyclonic storm surge floods in Bangladesh. Global Environmental Change. 2008; 18 (3):490-500.
Chicago/Turabian StyleM Karim; N Mimura. 2008. "Impacts of climate change and sea-level rise on cyclonic storm surge floods in Bangladesh." Global Environmental Change 18, no. 3: 490-500.