Hassan Qasem - Academia.edu (original) (raw)
Papers by Hassan Qasem
38th IAHR World Congress - "Water: Connecting the World", 2019
Doha Bay is a semi-enclosed water body, located on the Arabian Gulf, bordering Doha, capital city... more Doha Bay is a semi-enclosed water body, located on the Arabian Gulf, bordering Doha, capital city of the State of Qatar. It currently receives untreated waters via several marine outfalls from Doha and surrounding areas. The untreated water consists of stormwater, but is also likely to include discharges from nonstormwater sources, which may contribute additional pollutants to the receiving sea waters. Due to shallow depth near the stormwater discharge outlets in the Doha Bay, there is a potential public health risk to recreational users from accumulated pollutants. The key objective of this study is to determine the existing environmental conditions of the marine environment, in the vicinity of four primary discharge outfalls (i.e. Souq Waqif, Rumailah, Tennis Court and Diplomatic outfalls) in order to assess the spatial extent of the pollutants that may have dispersed from each Outfall. An extensive sampling program was undertaken that includes an assessment of water and sediment quality, hydrodynamics and identification of sensitive ecological communities within the Doha Bay area. To achieve this, a series of sampling stations were positioned along multiple transect lines radiating out from each discharge point. The results of sampling program were assessed for compliance against a range of local, regional and international ambient marine water quality standards as reported in this paper.
Natural Hazards, 2016
Design rainfall is needed in the design of numerous engineering infrastructures such as urban dra... more Design rainfall is needed in the design of numerous engineering infrastructures such as urban drainage systems, bridges, railways, metro systems, highways and flood levees. Design rainfall is derived using regional frequency analysis approach based on observed rainfall data from a large number of stations within a homogeneous region. This paper provides an assessment of the possible impacts of climate change on design rainfalls in Qatar. The future climate conditions are established based on AR4 and A2 categories of emission scenarios (SRES) specified by the Intergovernmental Panel on Climate Change. Predicted 24-h annual maximum rainfall series for both the wet (NCAR-CCSM) and dry scenarios (CSIRO-MK3.5) for the Qatari grid points are extracted for three different periods, which are current (2000-2029), medium-term (2040-2069) and end-of-century climates (2080-2099). Using an L-moments-based index frequency approach, homogeneous regions are established and the best-fit distribution is then used to derive rainfall quantiles for average recurrence intervals (ARIs) of 2, 5, 10, 25, 50 and 100 years. The results show that there is no significant change in the design rainfalls in Qatar in the short term covering 2040-2069; however, a significant change is predicted at the end of century covering 2080-2099. Updated design rainfalls are estimated considering climate change scenarios for the period of 2080-2099 by averaging results from the wet and dry climate scenarios. The increase in 24-h annual maximum rainfall for the period 2080-2099 (compared with the current period 2000-2029) is found to be in the range of 68 and 76 % for 100-year ARI. For the typical design ARIs of 10-20 years, the increase in design rainfall is found to be in the range of 43 and 54 %. The method presented in this study can be applied to other arid regions, in particular to the Middle Eastern countries.
International Journal of Sustainable Built Environment, 2014
For stormwater system design, flood estimation and many other environmental assessment tasks, des... more For stormwater system design, flood estimation and many other environmental assessment tasks, design rainfall is an essential input. Estimation of design rainfall is generally made using a regionalization technique based on a regional database of observed rainfalls. Many countries have derived their own generalized design rainfall data, which are generally expressed in the form of intensity-duration-frequency (IDF) curves. In Qatar, situated in an arid region, the existing IDF data were developed in 1991 using a limited data set. This paper presents the development of new IDF data for the State of Qatar using the method of L-moments and the index regional frequency analysis approach. The daily rainfall data from 32 stations located in Qatar and nearby Gulf countries have been used to form a homogeneous region. It has been found that the Pearson Type 3 distribution best fits the 24-h duration annual maximum rainfall data in the Qatar region. For the ungauged case, a prediction equation is developed where mean annual maximum rainfall is expressed as a function of climatic and physiographic characteristics. From a leave-one-out validation, it has been found that the developed prediction equation can estimate mean annual maximum rainfall with a median relative error of about 5.5%. Finally, an approximate method is used to obtain design rainfalls for other durations due to the limitations of continuous pluviograph data in Qatar. The new set of IDF curves is based on a much bigger dataset than the existing 1991 IDF curves. It is expected that the new IDF curves will have wider application in Qatar and will provide a statistically sound basis for storm water design, flood and environmental studies. The method can be applied Q5 to other middle-eastern states and similar arid countries in the world.
Design rainfall is a fundamental input to the planning, design and operation of many water and en... more Design rainfall is a fundamental input to the planning, design and operation of many water and environmental projects. Most countries have derived their own generalised design rainfall data, which is generally expressed in the form of intensity-duration-frequency (IDF) curves. In Qatar, situated in arid region, the existing IDF data was developed in 1991 using a limited data set. This paper presents the development of new IDF data for the State of Qatar using method of L-moments and index regional frequency analysis approach with the mean rainfall as the scaling factor. The daily rainfall data from 32 stations located in Qatar and nearby Gulf countries has been used to form a homogeneous region based on the criteria of Hosking and Wallis. It has been found that the Pearson Type 3 distribution best fits the 24-hour duration annual maximum rainfall data in the Qatar region. For ungauged case, a prediction equation is developed where mean annual maximum rainfall is expressed as a function of physiographic characteristics. From a leave-one-out validation, it has been found the developed prediction equation can estimate mean annual maximum rainfall with a median relative error of 5.5%. Finally, an approximate method is used to obtain design rainfalls for other durations due to the limitations of continuous pluviograph data. The new set of IDF curves are based on a much bigger dataset than the existing 1991 IDF curves. It is expected that the new IDF curves will have wider application in Qatar and will provide a statistically sound basis for storm water design, flood and environmental studies
Intergovernmental Panel for Climate Change (IPCC) in its fourth Assessment Report AR4 predicts a ... more Intergovernmental Panel for Climate Change (IPCC) in its fourth Assessment Report AR4 predicts a more extreme climate towards the end of the century, which is likely to impact the design of engineering infrastructure projects with a long design life. A recent study in 2013 developed new design rainfall for Qatar, which provides an improved design basis of drainage infrastructure for the State of Qatar under the current climate. The current design standards in Qatar do not consider increased rainfall intensity caused by climate change. The focus of this paper is to update recently developed design rainfalls in Qatar under the changing climatic conditions based on IPCC's AR4 allowing a later revision to the proposed design standards, relevant for projects with a longer design life. The future climate has been investigated based on the climate models released by IPCC’s AR4 and A2 story line of emission scenarios (SRES) using a stationary approach. Annual maximum series (AMS) of pre...
Weber, T., McPhee, M.J. and Anderssen, R.S. (eds) MODSIM2015, 21st International Congress on Modelling and Simulation, Nov 29, 2015
In stormwater system design, flood insurance studies and flood protection works, hydrological mod... more In stormwater system design, flood insurance studies and flood protection works, hydrological models are adopted to estimate design flows. Design flows are referred to as a runoff discharge associated with a given average recurrence interval (ARI) or annual exceedance probability (AEP). These models require design rainfall as the most important input among other inputs such as catchment characteristics representing runoff routing behaviour and losses. The design rainfall, often known as intensity-durationfrequency (IDF) data, is generally derived using a regional frequency analysis approach based on a group of rainfall stations that form a homogeneous region. An Australia, design rainfall is known as intensityfrequency-duration (IFD) data. A large degree of uncertainty is associated with IDF data, which often is not quantified and considered in majority of hydrologic modelling applications. This paper presents a modelling framework to quantify uncertainty in design rainfalls for Qatar due to uncertainties arising from limited data length and parameters of the adopted probability distribution model. Qatar is situated in arid region, which has limited rainfall data in terms of number of stations, resolution of data (e.g. only daily rainfall data is available for most of the stations) and record length of the available data. The proposed modelling framework accounts for the uncertainty in the rainfall data using a Monte Carlo simulation technique where a multivariate normal distribution is adopted in accounting for the uncertainty in the parameters of the log Pearson Type 3 (LP3) distribution. A bootstrapping method is adopted to estimate the mean and standard error values and the correlations among the three parameters of the LP3 distribution to define the multivariate normal distribution. A total of 10,000 simulations are carried out to develop the 90% confidence intervals for the 24-hour duration rainfall quantile. It has been found that uncertainty in IDF curves is quite high; to reduce the uncertainty band in estimated rainfall quantiles, a higher record length is needed, which however is not currently available in Qatar region. The proposed modelling framework is in the developmental stage, which is applied in this paper to a single station and for one rainfall duration (24-hour). The proposed method is being enhanced by adding other sources of uncertainties in design rainfall estimation e.g. uncertainty due to data quality and climate change. Furthermore, other rainfall durations from a large number of stations will be considered, which will enable better quantification of the uncertainty in the design rainfalls in Qatar.
For stormwater system design, flood estimation and many other environmental assessment tasks, des... more For stormwater system design, flood estimation and many other environmental assessment tasks, design rainfall is an essential input. Estimation of design rainfall is generally made using a regionalization technique based on a regional database of observed rainfalls. Many countries have derived their own generalized design rainfall data, which are generally expressed in the form of intensity-duration-frequency (IDF) curves. In Qatar, situated in an arid region, the existing IDF data were developed in 1991 using a limited data set. This paper presents the development of new IDF data for the State of Qatar using the method of L-moments and the index regional frequency analysis approach. The daily rainfall data from 32 stations located in Qatar and nearby Gulf countries have been used to form a homogeneous region. It has been found that the Pearson Type 3 distribution best fits the 24-h duration annual maximum rainfall data in the Qatar region. For the ungauged case, a prediction equation is developed where mean annual maximum rainfall is expressed as a function of climatic and physiographic characteristics. From a leave-one-out validation, it has been found that the developed prediction equation can estimate mean annual maximum rainfall with a median relative error of about 5.5%. Finally, an approximate method is used to obtain design rainfalls for other durations due to the limitations of continuous pluviograph data in Qatar. The new set of IDF curves is based on a much bigger dataset than the existing 1991 IDF curves. It is expected that the new IDF curves will have wider application in Qatar and will provide a statistically sound basis for storm water design, flood and environmental studies. The method can be applied to other middle-eastern states and similar arid countries in the world.
38th IAHR World Congress - "Water: Connecting the World", 2019
Doha Bay is a semi-enclosed water body, located on the Arabian Gulf, bordering Doha, capital city... more Doha Bay is a semi-enclosed water body, located on the Arabian Gulf, bordering Doha, capital city of the State of Qatar. It currently receives untreated waters via several marine outfalls from Doha and surrounding areas. The untreated water consists of stormwater, but is also likely to include discharges from nonstormwater sources, which may contribute additional pollutants to the receiving sea waters. Due to shallow depth near the stormwater discharge outlets in the Doha Bay, there is a potential public health risk to recreational users from accumulated pollutants. The key objective of this study is to determine the existing environmental conditions of the marine environment, in the vicinity of four primary discharge outfalls (i.e. Souq Waqif, Rumailah, Tennis Court and Diplomatic outfalls) in order to assess the spatial extent of the pollutants that may have dispersed from each Outfall. An extensive sampling program was undertaken that includes an assessment of water and sediment quality, hydrodynamics and identification of sensitive ecological communities within the Doha Bay area. To achieve this, a series of sampling stations were positioned along multiple transect lines radiating out from each discharge point. The results of sampling program were assessed for compliance against a range of local, regional and international ambient marine water quality standards as reported in this paper.
Natural Hazards, 2016
Design rainfall is needed in the design of numerous engineering infrastructures such as urban dra... more Design rainfall is needed in the design of numerous engineering infrastructures such as urban drainage systems, bridges, railways, metro systems, highways and flood levees. Design rainfall is derived using regional frequency analysis approach based on observed rainfall data from a large number of stations within a homogeneous region. This paper provides an assessment of the possible impacts of climate change on design rainfalls in Qatar. The future climate conditions are established based on AR4 and A2 categories of emission scenarios (SRES) specified by the Intergovernmental Panel on Climate Change. Predicted 24-h annual maximum rainfall series for both the wet (NCAR-CCSM) and dry scenarios (CSIRO-MK3.5) for the Qatari grid points are extracted for three different periods, which are current (2000-2029), medium-term (2040-2069) and end-of-century climates (2080-2099). Using an L-moments-based index frequency approach, homogeneous regions are established and the best-fit distribution is then used to derive rainfall quantiles for average recurrence intervals (ARIs) of 2, 5, 10, 25, 50 and 100 years. The results show that there is no significant change in the design rainfalls in Qatar in the short term covering 2040-2069; however, a significant change is predicted at the end of century covering 2080-2099. Updated design rainfalls are estimated considering climate change scenarios for the period of 2080-2099 by averaging results from the wet and dry climate scenarios. The increase in 24-h annual maximum rainfall for the period 2080-2099 (compared with the current period 2000-2029) is found to be in the range of 68 and 76 % for 100-year ARI. For the typical design ARIs of 10-20 years, the increase in design rainfall is found to be in the range of 43 and 54 %. The method presented in this study can be applied to other arid regions, in particular to the Middle Eastern countries.
International Journal of Sustainable Built Environment, 2014
For stormwater system design, flood estimation and many other environmental assessment tasks, des... more For stormwater system design, flood estimation and many other environmental assessment tasks, design rainfall is an essential input. Estimation of design rainfall is generally made using a regionalization technique based on a regional database of observed rainfalls. Many countries have derived their own generalized design rainfall data, which are generally expressed in the form of intensity-duration-frequency (IDF) curves. In Qatar, situated in an arid region, the existing IDF data were developed in 1991 using a limited data set. This paper presents the development of new IDF data for the State of Qatar using the method of L-moments and the index regional frequency analysis approach. The daily rainfall data from 32 stations located in Qatar and nearby Gulf countries have been used to form a homogeneous region. It has been found that the Pearson Type 3 distribution best fits the 24-h duration annual maximum rainfall data in the Qatar region. For the ungauged case, a prediction equation is developed where mean annual maximum rainfall is expressed as a function of climatic and physiographic characteristics. From a leave-one-out validation, it has been found that the developed prediction equation can estimate mean annual maximum rainfall with a median relative error of about 5.5%. Finally, an approximate method is used to obtain design rainfalls for other durations due to the limitations of continuous pluviograph data in Qatar. The new set of IDF curves is based on a much bigger dataset than the existing 1991 IDF curves. It is expected that the new IDF curves will have wider application in Qatar and will provide a statistically sound basis for storm water design, flood and environmental studies. The method can be applied Q5 to other middle-eastern states and similar arid countries in the world.
Design rainfall is a fundamental input to the planning, design and operation of many water and en... more Design rainfall is a fundamental input to the planning, design and operation of many water and environmental projects. Most countries have derived their own generalised design rainfall data, which is generally expressed in the form of intensity-duration-frequency (IDF) curves. In Qatar, situated in arid region, the existing IDF data was developed in 1991 using a limited data set. This paper presents the development of new IDF data for the State of Qatar using method of L-moments and index regional frequency analysis approach with the mean rainfall as the scaling factor. The daily rainfall data from 32 stations located in Qatar and nearby Gulf countries has been used to form a homogeneous region based on the criteria of Hosking and Wallis. It has been found that the Pearson Type 3 distribution best fits the 24-hour duration annual maximum rainfall data in the Qatar region. For ungauged case, a prediction equation is developed where mean annual maximum rainfall is expressed as a function of physiographic characteristics. From a leave-one-out validation, it has been found the developed prediction equation can estimate mean annual maximum rainfall with a median relative error of 5.5%. Finally, an approximate method is used to obtain design rainfalls for other durations due to the limitations of continuous pluviograph data. The new set of IDF curves are based on a much bigger dataset than the existing 1991 IDF curves. It is expected that the new IDF curves will have wider application in Qatar and will provide a statistically sound basis for storm water design, flood and environmental studies
Intergovernmental Panel for Climate Change (IPCC) in its fourth Assessment Report AR4 predicts a ... more Intergovernmental Panel for Climate Change (IPCC) in its fourth Assessment Report AR4 predicts a more extreme climate towards the end of the century, which is likely to impact the design of engineering infrastructure projects with a long design life. A recent study in 2013 developed new design rainfall for Qatar, which provides an improved design basis of drainage infrastructure for the State of Qatar under the current climate. The current design standards in Qatar do not consider increased rainfall intensity caused by climate change. The focus of this paper is to update recently developed design rainfalls in Qatar under the changing climatic conditions based on IPCC's AR4 allowing a later revision to the proposed design standards, relevant for projects with a longer design life. The future climate has been investigated based on the climate models released by IPCC’s AR4 and A2 story line of emission scenarios (SRES) using a stationary approach. Annual maximum series (AMS) of pre...
Weber, T., McPhee, M.J. and Anderssen, R.S. (eds) MODSIM2015, 21st International Congress on Modelling and Simulation, Nov 29, 2015
In stormwater system design, flood insurance studies and flood protection works, hydrological mod... more In stormwater system design, flood insurance studies and flood protection works, hydrological models are adopted to estimate design flows. Design flows are referred to as a runoff discharge associated with a given average recurrence interval (ARI) or annual exceedance probability (AEP). These models require design rainfall as the most important input among other inputs such as catchment characteristics representing runoff routing behaviour and losses. The design rainfall, often known as intensity-durationfrequency (IDF) data, is generally derived using a regional frequency analysis approach based on a group of rainfall stations that form a homogeneous region. An Australia, design rainfall is known as intensityfrequency-duration (IFD) data. A large degree of uncertainty is associated with IDF data, which often is not quantified and considered in majority of hydrologic modelling applications. This paper presents a modelling framework to quantify uncertainty in design rainfalls for Qatar due to uncertainties arising from limited data length and parameters of the adopted probability distribution model. Qatar is situated in arid region, which has limited rainfall data in terms of number of stations, resolution of data (e.g. only daily rainfall data is available for most of the stations) and record length of the available data. The proposed modelling framework accounts for the uncertainty in the rainfall data using a Monte Carlo simulation technique where a multivariate normal distribution is adopted in accounting for the uncertainty in the parameters of the log Pearson Type 3 (LP3) distribution. A bootstrapping method is adopted to estimate the mean and standard error values and the correlations among the three parameters of the LP3 distribution to define the multivariate normal distribution. A total of 10,000 simulations are carried out to develop the 90% confidence intervals for the 24-hour duration rainfall quantile. It has been found that uncertainty in IDF curves is quite high; to reduce the uncertainty band in estimated rainfall quantiles, a higher record length is needed, which however is not currently available in Qatar region. The proposed modelling framework is in the developmental stage, which is applied in this paper to a single station and for one rainfall duration (24-hour). The proposed method is being enhanced by adding other sources of uncertainties in design rainfall estimation e.g. uncertainty due to data quality and climate change. Furthermore, other rainfall durations from a large number of stations will be considered, which will enable better quantification of the uncertainty in the design rainfalls in Qatar.
For stormwater system design, flood estimation and many other environmental assessment tasks, des... more For stormwater system design, flood estimation and many other environmental assessment tasks, design rainfall is an essential input. Estimation of design rainfall is generally made using a regionalization technique based on a regional database of observed rainfalls. Many countries have derived their own generalized design rainfall data, which are generally expressed in the form of intensity-duration-frequency (IDF) curves. In Qatar, situated in an arid region, the existing IDF data were developed in 1991 using a limited data set. This paper presents the development of new IDF data for the State of Qatar using the method of L-moments and the index regional frequency analysis approach. The daily rainfall data from 32 stations located in Qatar and nearby Gulf countries have been used to form a homogeneous region. It has been found that the Pearson Type 3 distribution best fits the 24-h duration annual maximum rainfall data in the Qatar region. For the ungauged case, a prediction equation is developed where mean annual maximum rainfall is expressed as a function of climatic and physiographic characteristics. From a leave-one-out validation, it has been found that the developed prediction equation can estimate mean annual maximum rainfall with a median relative error of about 5.5%. Finally, an approximate method is used to obtain design rainfalls for other durations due to the limitations of continuous pluviograph data in Qatar. The new set of IDF curves is based on a much bigger dataset than the existing 1991 IDF curves. It is expected that the new IDF curves will have wider application in Qatar and will provide a statistically sound basis for storm water design, flood and environmental studies. The method can be applied to other middle-eastern states and similar arid countries in the world.