11 research outputs found

    SWAT model application to estimate runoff for ungauged arid catchments experiencing rapid urbanisation: Riyadh case study

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    The built-up area of Riyadh city increased from approximately 4.5 km² in 1950 to reach approximately 1,600 km² by 2022 spreading over vast areas of the Wadi Hanifah and Wadi As Silayy catchments. The rapid growth of the city has led to repeated urban flooding. There is an urgent need to study surface runoff and how it is affected by land-use/land-cover (LULC) change in the ungauged catchments of the city. This study addressed that knowledge gap and was the first attempt to calibrate, validate, and run a semi-distributed model to simulate runoff depths and discharge rates for Riyadh's main catchments and sub-basins using five historical and five future scenarios. The Soil Water Assessment Tool (SWAT) was used for the modelling. TerraClimate evapotranspiration (ET) data was used to calibrate the SWAT model owing to a dearth of observed runoff data across Riyadh city. The literature review revealed that the use of Terraclimate ET to calibrate SWAT models is still very limited so far. The only previous study found is Herman et al. (2020). Therefore, this study is fairly unique in that it uses Terraclimate ET to successfully calibrate and validate a SWAT model. A one-by-one sensitivity analysis was performed to evaluate the impact of changing parameter values on the runoff simulations. The results indicated that simulated runoff sensitivity to selected parameter values in the calibrated SWAT models was minimal in the study area, where the relationships between simulated annual runoff and max and min runoff resulted in a very strong R2 (0.9998). The calibrated and validated SWAT models were run monthly and daily to simulate runoff and to assess the impact of several LULC change scenarios on surface runoff for both historical and future periods. The results of SWAT models of the main catchments and sub-basins located within the built-up areas demonstrated the positive effect of Riyadh’s development on runoff and discharge values for historical LULC scenarios and LULC 2030 probabilities scenarios. But the increasing rates of simulated runoff were not the same for all sub-basins due to the different proportions of urbanisation in each sub-basin. On the contrary, simulation results showed that runoff depths and discharge rates in sub-basins outside the boundaries of the built-up areas of Riyadh did not have significant changes when using historical LULC scenarios or LULC 2030 probabilities scenarios. The increase in runoff depths and discharge rates in the sub-basins reflected the direct influence of the urbanisation process on surface runoff. The increase in simulated surface runoff and discharge can be attributed mainly to the potential decrease of relatively permeable barren lands and the increase of impervious urban surfaces. Limitations faced during the SWAT model development suggest further research should aim to get detailed and accurate runoff estimates in Riyadh city to sufficiently assist decision-makers and city officials to adopt runoff and flood hazard management schemes in the city

    SWAT model application to estimate runoff for ungauged arid catchments experiencing rapid urbanisation: Riyadh case study

    Get PDF
    The built-up area of Riyadh city increased from approximately 4.5 km² in 1950 to reach approximately 1,600 km² by 2022 spreading over vast areas of the Wadi Hanifah and Wadi As Silayy catchments. The rapid growth of the city has led to repeated urban flooding. There is an urgent need to study surface runoff and how it is affected by land-use/land-cover (LULC) change in the ungauged catchments of the city. This study addressed that knowledge gap and was the first attempt to calibrate, validate, and run a semi-distributed model to simulate runoff depths and discharge rates for Riyadh's main catchments and sub-basins using five historical and five future scenarios. The Soil Water Assessment Tool (SWAT) was used for the modelling. TerraClimate evapotranspiration (ET) data was used to calibrate the SWAT model owing to a dearth of observed runoff data across Riyadh city. The literature review revealed that the use of Terraclimate ET to calibrate SWAT models is still very limited so far. The only previous study found is Herman et al. (2020). Therefore, this study is fairly unique in that it uses Terraclimate ET to successfully calibrate and validate a SWAT model. A one-by-one sensitivity analysis was performed to evaluate the impact of changing parameter values on the runoff simulations. The results indicated that simulated runoff sensitivity to selected parameter values in the calibrated SWAT models was minimal in the study area, where the relationships between simulated annual runoff and max and min runoff resulted in a very strong R2 (0.9998). The calibrated and validated SWAT models were run monthly and daily to simulate runoff and to assess the impact of several LULC change scenarios on surface runoff for both historical and future periods. The results of SWAT models of the main catchments and sub-basins located within the built-up areas demonstrated the positive effect of Riyadh’s development on runoff and discharge values for historical LULC scenarios and LULC 2030 probabilities scenarios. But the increasing rates of simulated runoff were not the same for all sub-basins due to the different proportions of urbanisation in each sub-basin. On the contrary, simulation results showed that runoff depths and discharge rates in sub-basins outside the boundaries of the built-up areas of Riyadh did not have significant changes when using historical LULC scenarios or LULC 2030 probabilities scenarios. The increase in runoff depths and discharge rates in the sub-basins reflected the direct influence of the urbanisation process on surface runoff. The increase in simulated surface runoff and discharge can be attributed mainly to the potential decrease of relatively permeable barren lands and the increase of impervious urban surfaces. Limitations faced during the SWAT model development suggest further research should aim to get detailed and accurate runoff estimates in Riyadh city to sufficiently assist decision-makers and city officials to adopt runoff and flood hazard management schemes in the city

    The Reading Perception Of Medical Staff About The Use Of Prehospital Ultrasound

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    This study was a focus on the use of pre-hospital ultrasound in Saudi Arabia. Generally, ultrasound is used in a high frequency by health care providers in different countries within hospitals or pre-hospital. The main point of using the ultrasound was to reduce the time of diagnosis at the hospital and decrease the rate of mortality and morbidity. The study was a cross-sectional study and was used to assess the perception of medical staff about the use of pre-hospital ultrasound. This survey study had 130 participants, and 80 of them were agreed to involve in this study. It was conducted in King Abdulaziz Hospital of National Guards, Al Ahsa and College of Applied Medical Sciences, King Saud Bin Abdul Aziz University for Health Sciences, Al Ahsa Campus, Saudi Arabia. ATLAST ti 8 was used for systematic literature review and SPSS v23 obviously for data analysis. This was a new and novel study as the Pre-hospital ultrasound was not used before in the pre-hospital. On the other hand, the findings showed that the participants displayed a high level of interest in improving their knowledge and skills of using ultrasound during its application in the pre-hospital setting. It was also recommended to have more research in future on the subject

    Hydrocele of the canal of Nuck

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    Hydrocele of the canal of Nuck is a rare condition in female children caused by a failure of complete obliteration of the canal of Nuck. The canal of Nuck is an abnormal patent pouch of the peritoneum extending anterior to the round ligament of the uterus into the labia majora. Incomplete obliteration of this canal (patent processus vaginalis) can result in either an inguinal hernia or a hydrocele. Here, we report two cases of hydrocele of the canal of Nuck presented within a two-month period. In the first case, incarcerated right-sided inguinal hernia was suspected while the second case was clinically diagnosed as encysted hydrocele of canal of Nuck. Both patients underwent surgical exploration. Hydrocelectomy with high ligation was also performed. One month after the surgery, the first patient showed signs of hydrocele on contralateral side, while the other patient showed no sign of contralateral hydrocele or hernia

    THE READING PERCEPTION OF MEDICAL STAFF ABOUT THE USE OF PREHOSPITAL ULTRASOUND

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    This study was a focus on the use of pre-hospital ultrasound in Saudi Arabia. Generally, ultrasound is used in a high frequency by health care providers in different countries within hospitals or pre-hospital. The main point of using the ultrasound was to reduce the time of diagnosis at the hospital and decrease the rate of mortality and morbidity. The study was a cross-sectional study and was used to assess the perception of medical staff about the use of pre-hospital ultrasound. This survey study had 130 participants, and 80 of them were agreed to involve in this study. It was conducted in King Abdulaziz Hospital of National Guards, Al Ahsa and College of Applied Medical Sciences, King Saud Bin Abdul Aziz University for Health Sciences, Al Ahsa Campus, Saudi Arabia. ATLAST ti 8 was used for systematic literature review and SPSS v23 obviously for data analysis. This was a new and novel study as the Pre-hospital ultrasound was not used before in the pre-hospital. On the other hand, the findings showed that the participants displayed a high level of interest in improving their knowledge and skills of using ultrasound during its application in the pre-hospital setting. It was also recommended to have more research in future on the subject

    A Success Story in Controlling Sand and Dust Storms Hotspots in the Middle East

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    Using 30 years of satellite observations, two sand and dust storms (SDS) source locations (hotspots) were detected on the southern side of the Mesopotamian Flood Plain. Around 40 million people in the region are affected by the two hotspots, including populations in Iraq, Iran, Kuwait, Saudi Arabia, Qatar, Bahrain, and Emirates. Both hotspots encompass roughly 8212 km2 and contribute 11% to 85% in 2005 and 2021, respectively, of the total SDS in the region. Dust physical (particle surface area and size percentages) and chemical (mineralogy, major and trace elements, and radionuclides) properties show close similarities between source and downwind samples during SDS originated solely from the two hotspots. Deposited dust size particles show a finning trend towards the north in the Middle East compared to the south. A comprehensive assessment of the chemical and physical properties of soil and dust samples was conducted as an essential step in developing and implementing a mitigation plan in order to establish a success story in reducing SDS, improving air quality, and benefiting the gulf countries and neighboring regions

    Identification and Characterization of Plasmids and Genes from Carbapenemase-Producing Klebsiella pneumoniae in Makkah Province, Saudi Arabia

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    Klebsiella pneumoniae (K. pneumoniae) is involved in several hospital and community-acquired infections. The prevalence of K. pneumoniae-producing-carbapenemase (KPC) resistance genes rapidly increases and threatens public health worldwide. This study aimed to assess the antibiotic resistance level of K. pneumoniae isolates from Makkah Province, Saudi Arabia, during the Islamic ‘Umrah’ ritual and to identify the plasmid types, presence of genes associated with carbapenem hydrolyzing enzymes, and virulence factors. The phenotypic and genotypic analyses based on the minimum inhibitory concentration (MIC), biofilm formation, PCR, and characterization of KPC-encoding plasmids based on the replicon typing technique (PBRT) were explored. The results showed that most isolates were resistant to carbapenem antibiotics and other antibiotics classes. This study identified sixteen different replicons of plasmids in the isolates and multiple genes encoding carbapenem factors, with blaVIM and blaOXA-48 being the most prevalent genes identified in the isolates. However, none of the isolates exhibited positivity for the KPC production activity. In addition, this study also identified six virulence-related genes, including kfu, wabG, uge, rmpA, fimH, and a capsular polysaccharide (CPS). Together, the data reported in this study indicate that the isolated K. pneumoniae during the pilgrimage in Makkah were all resistant to carbapenem antibiotics. Although the isolates lacked KPC production activity, they carried multiple carbapenem-resistant genes and virulence factors, which could drive their resistant phenotype. The need for specialized methods for KPC detection, monitoring the possibility of nosocomial transmission, and diverse therapeutic alternatives are necessary for controlling the spreading of KPC. This study can serve as a reference for clinicians and researchers on types of K. pneumoniae commonly found during religious gathering seasons in Saudi Arabia

    Lessons Learned from Large-Scale, First-Tier Clinical Exome Sequencing in a Highly Consanguineous Population

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