37 research outputs found

    Study of the hydrodynamic processes of rivers and floodplains with obstructions

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    A study has been undertaken to supplement design methods and develop innovative approaches for the effective management of rivers and floodplains to reduce flood risk. The focus has been on enhancing the understanding and representation of the hydrodynamic processes of a variety of flow conditions and the associated hydraulic interaction with selected obstruction types, such as mangroves and vehicles for the representative river basins of the Merbok and Klang, on the West Coast of Peninsular Malaysia, and the Valency, near Boscastle, in the UK. For the study of the hydrodynamic processes of natural floodplains, a numerical model has been refined to investigate the effects of mangroves on tsunamis, with the inclusion of modelling idealised test cases. A similar model has then been applied to a mangrove fringed floodplain for the Merbok river basin. In recognising the importance of mangroves as natural defences against flooding disasters, a novel innovative and environmentally friendly approach, namely the Artificial Mangrove Shelter (AMS), has been first initiated and modelled, for the sustainable restoration and rehabilitation of mangroves along floodplains. In studying the hydrodynamic processes of urban floodplains, a series of experimental investigations has been undertaken on stationary scaled model vehicles in laboratory flumes, to study the effects of vehicles on flood flow propagation and, the influence of the flood flows on the stability of the vehicles. In order to develop a useful innovative approach to evaluate the degree of hydraulic stability for vehicles, a novel three colour zone envelope curve has been first introduced and developed, herein known as the Traffic Light of Hydraulic Stability (TLHS), to identify the likelihood of vehicle movement. The study was then extended to investigate the consequential hydraulic impact of flooded vehicles on blocked bridges, through a physical modelling study in a laboratory flume, with the purpose being to replicate a typical section of prototype floodplain conditions for the Boscastle and Klang. In this study, eventually natural and urban environments along the rivers and floodplains have consideration the hydrodynamic processes and interaction between hydraulic obstructions and flood flows, with novel and practical approaches being developed for effective management of rivers and floodplains

    Study of the hydrodynamic processes of rivers and floodplains with obstructions

    Get PDF
    A study has been undertaken to supplement design methods and develop innovative approaches for the effective management of rivers and floodplains to reduce flood risk. The focus has been on enhancing the understanding and representation of the hydrodynamic processes of a variety of flow conditions and the associated hydraulic interaction with selected obstruction types, such as mangroves and vehicles for the representative river basins of the Merbok and Klang, on the West Coast of Peninsular Malaysia, and the Valency, near Boscastle, in the UK. For the study of the hydrodynamic processes of natural floodplains, a numerical model has been refined to investigate the effects of mangroves on tsunamis, with the inclusion of modelling idealised test cases. A similar model has then been applied to a mangrove fringed floodplain for the Merbok river basin. In recognising the importance of mangroves as natural defences against flooding disasters, a novel innovative and environmentally friendly approach, namely the Artificial Mangrove Shelter (AMS), has been first initiated and modelled, for the sustainable restoration and rehabilitation of mangroves along floodplains. In studying the hydrodynamic processes of urban floodplains, a series of experimental investigations has been undertaken on stationary scaled model vehicles in laboratory flumes, to study the effects of vehicles on flood flow propagation and, the influence of the flood flows on the stability of the vehicles. In order to develop a useful innovative approach to evaluate the degree of hydraulic stability for vehicles, a novel three colour zone envelope curve has been first introduced and developed, herein known as the Traffic Light of Hydraulic Stability (TLHS), to identify the likelihood of vehicle movement. The study was then extended to investigate the consequential hydraulic impact of flooded vehicles on blocked bridges, through a physical modelling study in a laboratory flume, with the purpose being to replicate a typical section of prototype floodplain conditions for the Boscastle and Klang. In this study, eventually natural and urban environments along the rivers and floodplains have consideration the hydrodynamic processes and interaction between hydraulic obstructions and flood flows, with novel and practical approaches being developed for effective management of rivers and floodplains.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

    Trend assessment of changing climate patterns over the major agro-climatic zones of Sindh and Punjab

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    The agriculture sector, due to its significant dependence on climate patterns and water availability, is highly vulnerable to changing climate patterns. Pakistan is an agrarian economy with 30% of its land area under cultivation and 93% of its water resources being utilized for agricultural production. Therefore, the changing climate patterns may adversely affect the agriculture and water resources of the country. This study was conducted to assess the climate variations over the major agro-climatic zones of Sindh and Punjab, which serve as an important hub for the production of major food and cash crops in Pakistan. For this purpose, the climate data of 21 stations were analyzed using the Mann–Kendall test and Sen's slope estimator method for the period 1990–2022. The results obtained from the analysis revealed that, in Sindh, the mean annual temperature rose by ~0.1 to 1.4°C, with ~0.1 to 1.2°C in cotton-wheat Sindh and 0.8 to 1.4°C in rice-other Sindh during the study period. Similarly, in Punjab, the mean annual temperature increased by ~0.1 to 1.0°C, with 0.6 to 0.9°C in cotton-wheat Punjab and 0.2 to 0.6°C in rainfed Punjab. Seasonally, warming was found to be highest during the spring season. The precipitation analysis showed a rising annual precipitation trend in Sindh (+30 to +60 mm) and Punjab (+100 to 300 mm), while the monsoon precipitation increased by ~50 to 200 mm. For winter precipitation, an upward trend was found in mixed Punjab, while the remaining stations showed a declining pattern. Conclusively, the warming temperatures as found in the analysis may result in increased irrigation requirements, soil moisture desiccation, and wilting of crops, ultimately leading to low crop yield and threatening the livelihoods of local farmers. On the other hand, the increasing precipitation may favor national agriculture in terms of less freshwater withdrawals. However, it may also result in increased rainfall-induced floods inundating the crop fields and causing water logging and soil salinization. The study outcomes comprehensively highlighted the prevailing climate trends over the important agro-climatic zones of Pakistan, which may aid in devising an effective climate change adaptation and mitigation strategy to ensure the state of water and food security in the country

    Green Wall as Urban Flood Mitigation

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    This study intends to look into modular-typed green wall, specifically with coconut peat as the growing medium. Commonly, such design is attached to vertical outdoor wall. Therefore, it is suggested to direct roof runoff to the green wall as an urban flood mitigation strategy. Characteristics of coconut peat are investigated through experimental works. The application as urban runoff control is demonstrated through a modelling case study of a typical commercial lot. SWMM model is developed by taking the advantage of its low impact development interface to apply bio-retention system as a green wall. Scenarios of using dry and saturated coconut peats are subjected to intense 15-minute 10-year ARI storm event. Outputs of the model suggest that a straight column of green wall modules in 700 mm wide, 200 mm thick and 12000 mm high is capable to fully capture the 6.3 m3 of total roof runoff generated by the design storm. Hence, the idea of adopting green wall for urban flood mitigation is encouraging

    A Sustainable Indoor Air Quality Monitoring Approach through Potable Living Wall for Closed Confined Spaces: A Way Forward to Fight Covid19

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    The COVID-19 pandemic has greatly influenced various aspects of life, part of which has consequently paved the way toward improvements in building design criteria, especially for closed confined spaces. The closed confined spaces are directly proportional to the quantity and quality of the volatile organic compounds (VOCs) present in the atmosphere, from which human beings breathe. In managing the impact produced by VOCs, a practical, sustainable, economical and environmentally friendly concept of indoor living walls has become a prominent feature for improving the indoor air quality (IAQ) of closed confined spaces to efficiently reduce sick building syndrome (SBS) factors. In modification of common practice of ventilation systems, living wall technology leverages the natural ability of plants to purify indoor air quality by reducing air pollutants and allows the recycling of indoor air and the creation of a productive and inspiring environment. In this paper, the concept of a portable living wall through the use of a native plant species locally available in Sindh, Pakistan is introduced. Herein, the portable living concept was assessed by means of the design, construction, and data collection (testing and monitoring) of various environmental parameters carried out before and after the installation of the living wall. The study was monitored for 90 days, and analyses for various types of air pollutants were carried out in the environmental laboratory. During the monitoring period, the parameters humidity, VOCs, hazardous chemicals of concern (HCOC), CO2 and CO showed reductions in their values, with changes observed ranging from 61.5 to 58%, 0.66 to 0.01 ppm, 0.2 to 0.01 ppm, 1070 to 528 ppm and 0.2 to 0.01 ppm, respectively. The outcomes showed noticeable changes in air pollutants coupled with reductions in heating, ventilation and air conditioning (HVAC) energy consumption by up to 25%, mainly due to limited air requirements for ventilation

    Evaluation of stormwater runoff quality during monsoon and inter-monsoon seasons at tropical urban catchments

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    Information on pollution level and the influence of a hydrologic regime on stormwater pollutant loading in tropical urban areas remains scarce. More local data is still required, as rainfall and runoff generation processes in tropical environment differ greatly from temperate regions. This study compares the stormwater runoff quality from urban catchments during monsoon and inter-monsoon seasons in the south of Peninsular Malaysia. Stormwater samples and flow rate data were collected from 38 storm events at three individual sites. Samples were analysed for total suspended solids (TSS), 5-day biochemical oxygen demand (BOD), chemical oxygen demand (COD), oil and grease (O&G), nitrate nitrogen (NO3-N), ammoniacal nitrogen (NH3-N), and total phosphorus (TP). Event mean concentration (EMC) was calculated for each pollutant for every monitored storm event at all study sites. The Mann–Whitney test was used to test for significance (p < 5%) in differences between the median EMCs of the pollutants. The results revealed that EMCs for stormwater runoff during the monsoon season were lower than that during the inter-monsoon season. Significant differences (p <.05) were found for EMC values for TSS, oil and grease, NH3-N, and TP but not for BOD, COD, and NO3-N. Stormwater pollutant loading of TSS, NH3-N, and TP is higher during the inter-monsoon season while BOD, COD, and NO3-N show higher loadings during the monsoon season. A better understanding of pollutant transport mechanisms will aid in formulating an effective stormwater management measures to control the urban stormwater pollution in the tropics
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