Extensive land subsidence and submergence occurred in the coal mining areas (Huainan and Huaibei) in Anhui Province, China. As a result, lots of subsided lakes have been formed due to their unique geological features. Four typical lakes were selected to evaluate the internal phosphorus (P) releasing risk based on the specification of P, Fe and Al from the sediments. Sediment P, Fe and Al in the top 5 cm were extracted sequentially, aiming at obtained fractionation for environmental indicators. Experiments of P isothermal adsorption were conducted to characterize P sorption ability. The results suggested that P internal loading potential was related to Al and Fe compounds in sedimentary environments of soil inundation, primarily determined by regional soil properties. Internal P releasing risk was mainly controlled by the properties of calcareous soils in the Huaibei; whereas controlled by Fe and Al in the Huainan. Overall, the obtained results fit well with the model proposed by Kopáček et al.(2005), which predicted low P flux as molar ratio of [NH4Cl-Al + BD-Al + NaOH-Al] : [NH4Cl-Fe + BD-Fe] >3 or [NaOH-Al] : [NH4Cl-P + BD-P] >25 from sediments when anoxia is developed. However, this threshold has site-specific flexibility, with its lower limit approaching 20:1 applicable for the three lakes in Huainan. Higher loads of external input organic matters or enriched Fe oxides bound P tend to change this limit and lead to internal loading risk with environmental anoxia.

Prestressing steel is an effective means of increasing the load carrying capacity and control the deflection of structural steel members. Although the method of prestressing is not new, the application and development of the technique for steel members has been limited and not as advanced as prestressed concrete structures. Prestressing force is commonly introduced using hydraulic jacks and utilizes high strength tendons as the prestressing material. In this paper, a new method of applying prestressing force is introduced. The method involves a segmental beam consisting of three segments and a normal strength bottom plate (BP) as the pretressing material attached to the two initially inclined outer segments of the steel H-beam. Pretressing force is introduced by taking advantage of the geometry of the segmental assembly of the beam. Experiment, analytical studies, and finite element (FE) analysis using ABAQUS is performed to verify the feasibility and applicability of the method and to understand the behavior of a mechanically prestressed segmental steel beam. Results showed that the prestressing method significantly increases the load carrying capacity and at the same time reduces the deflection of the beam. The difficulties encountered in the method are the rigorous assembly and the introduction of the exact required amount of prestressing force. Overall, the method of prestressing performed in the study can be used to introduce pretressing force which improves the performance of steel beams, provided that proper detailing is implemented.

A numerical approximation for modeling morphological behavior in open channels is presented in this paper. The scheme is based on Godunov-type finite volume method which is preferred for its conservation preserving ability. The Saint Venant equations for river flow coupled with sediment continuity form the governing system of equations. Flux computation through cell interfaces is computed by Harten-Lax-van Leer-Contact (HLLC) approximate Riemann solver method at each time step. Second-order temporal and spatial accuracy is confirmed by employing Henn’s method and high-order reconstruction technique with limited gradient, respectively. The coupled model is able to handle discontinuities in surface water flow and bed profiles, and prevent spurious oscillations in all cases. A hydrostatic reconstruction technique is used to handle wet-dry fronts and avoid negative water depths and unphysical high velocities in complex domains. A modification in surface gradient method satisfies the well-balancing between flux computations of momentum and slope-source terms. Comparison of model-results for various tests with their analytical and experimental solutions shows that our numerical scheme is robust in simulating steady and unsteady flows over a various domains.

Clogging of the filter media which is brought by physical, chemical, and biological factors tend to reduce the lifespan of filters and remains a challenge. In this study, a laboratory column test method was used to investigate the evolution of physical and biological clogging in a non-vegetated filter media system with layers of sand, gravel, and woodchip. Blank column tests using either sand or gravel were conducted and investigated. Several column setups with varying arrangements and particle sizes of sand and gravel were also prepared to identify the best filter media combination that is least susceptible to clogging without compromising the treatment capacity. Artificial stormwater runoff was introduced in the system at a specific hydraulic loading rate (HLR) and influent characteristics. The degree of clogging was quantified by monitoring the variations in the hydraulic head at different levels of the columns. Water samples were also collected, tested, and analyzed at the end of each test run in order to measure the treatment efficiency of the filter. The insights and results of this study can justify the physical and biological clogging formation in filter media and therefore be used to suggest some filter media particle size modifications that can help to improve the sediment removal and treatment performance. Moreover, it can also aid to reduce the maintenance frequency and costs of a stormwater filter system.

Future climate change is expected to raise the mean sea level of Korea by about 0.85m-1.29m. Consequently, flood damage in the coastal area would likewise increase and the scale of damage would also become much larger. Various researches have been conducted to efficiently respond to natural disasters caused by climate change. However, there haven’t been many researches related to the analysis and evaluation of coastal area flood vulnerability caused by the rise in sea level. Hence, this study selected Gilsan River basin, a branch of Geum River as the subject matter and tried to evaluate the effect of sea level rise caused by climate change on the coastal area and adjacent rivers. This study also calculated the change in water quantity in the coastal area by considering the sea level rise as well as the future precipitation according to climate change. It also prepared/compared the relevant flood inundation map. The study result showed that the overall flood level increased as the elevation of the water surface rose due to the rise in sea level. In addition, the extent of increase in flood level caused by sea level rise was greater at a location nearer the outlet and it was smaller at a place farther from the outlet. Based on this result, it could be verified that in coastal rivers, climate change can have an effect not only on the precipitation increase but also on the flood water level and flood inundation due to the rise in sea level. The result of this study could be used as basic data for creating technology that would assess the flood vulnerability of coastal urban regions and evaluate preventive measures for coastal disaster risks.

This study analyzes the buckling safety in the area of circumferentially edge-stiffened door openings without any additional longitudinal stiffeners of offshore tubular steel towers. The tubular steel tower is subjected to six (6) different load situations which are deemed to be normal and abnormal operating cases for the ultimate limit state. Analytical method using parametric equations based on Eurocode 3 - Design of Steel Structures and numerical method of finite element are used to analyze the critical meridional buckling stress. ABAQUS, a finite element program, is used for the numerical method analysis. Buckling safety analysis in the localized area near the opening is studied, and points of interest are defined for comparison between the two aforementioned analyses. Findings are tabulated and shown in illustrative charts, and conclusions are made.

Drought prediction is of significance importance for drought disaster risk management and mitigation. The regression based statistical models and physical process based models are commonly used for drought prediction. The statistical models assume stationarity of data which limits their ability to capture highly non-linear patterns of droughts. On the other hand, reliable long-range rainfall forecast is necessary for drought prediction using physical process based models. However, the long-range rainfall prediction especially in the Asian monsoon regions is quite challenging for climate models. In this study, the use of Adaptive Neuro-Fuzzy Inference System (ANFIS) was explored to develop a model for prediction of droughts over the East Asia monsoon region (20oN–50oN,103oE–149oE) by employing Standardized Precipitation Index (SPI) as a drought index. Most of the drought studies in the East Asia have been focused on basin or country scale. In this study, we identified homogeneous rainfall zones in the East Asia monsoon region using cluster analysis methods and analyzed the impact of global Sea Surface Temperature Anomalies (SSTA) on drought in each zone. The ANFIS-based model was developed and evaluated with different configurations to identify optimal model architecture and suitable predictor variables for drought prediction. The performance of the proposed model was assessed by comparison of observed and predicted values of the drought index using different statistical measures.

The presence of pharmaceuticals in the environment has led to apparent toxicity with different aquatic species. Clarithromycin, for example, is used in treating respiratory tract infections, has been recently found in the surface waters and rivers which might threaten non-targeted organisms in these matrices. In this study, a model vertebrate Danio rerio (zebrafish) was exposed to 100ppb clarithromycin for 72 hours to evaluate acute toxicity through significantly affected metabolic compounds in the fish’s pathway. Metabolites obtained from q-TOF LC/MS were identified and mapped with the zebrafish’s metabolic pathway using Metlin, and KEGG respectively. 335 compounds are believed to have been significantly altered by the acute exposure of the antibiotic with the fish. The most affected pathways are ABC transporters, steroid hormone biosynthesis, arachidonic acid metabolism, purine metabolism, and biosynthesis of amino acids. With the said findings, it can be concluded that, although concentration of some pharmaceuticals may be as low as the one used in this study, its effects on the aquatic species exposed to it might be significant and should be given immediate attention

Biofilters are widely used for treating various types of wastewater and also recently in controlling non-point source (NPS) pollution including piggery stormwater. Gravels are common substrates employed in this type of biofilters. In this study, three parallel woodchip based biofilters with different thickness of woodchip layer were constructed and operated for about 300 days in 2013. Sampling was conducted every 2 days. The water temperature, pH, electric conductivity (EC), turbidity and DO were measured in situ. Other water quality parameters were analyzed in accordance with the Standard Methods for the Examination of Water and Wastewater (APHA et al. 1995). On one hand, with less woodchip media packed in the biofilter, better removal of TN, TP, NH4-N, TCOD was achieved. On the other hand, almost all NO3-N were removed regardless of the thickness of woodchip. In addition, with deeper thickness of woodchip media in the biofilter, more increased alkalinity and released organic matters were observed at the effluent. Alkalinity is important in biological nitrogen processes, especially in the reactions of ammonia transformation into nitrate (nitrification). Organic matters released from woodchip served as the carbon source to derive denitrification. It seems that only small amount of the woodchip were sufficient to achieve nice removal of nitrogen and phosphorus. Therefore, the amount of the woodchip could be a key in designing a woodchip biofilter.

In this study, the time-area curve for an elliptical shaped basin was analytically derived. The assumptions introduced to derive the time-area curve are as follows. First, an infinite number of raindrops reach the impervious surface of the elliptical shaped basin evenly in space. Second, the vertical axis of the ellipse is assumed to be the channel of the elliptical shaped basin. Third, the direction of the surface runoff is always perpendicular to the channel flow. Fourth, the flow velocity remains the same in any location within each channel and land surface, the ratio of their flow velocity is consistent everywhere within the basin. As a result, the time-area curve for the basin can be derived with the equivalent ellipse of the basin along with the proper characteristic velocity within each channel and land surface. Furthermore, by multiplying the flow velocity with this time-area curve, one can derive the inflow to the linear reservoir, of which the outflow becomes the Clark IUH.

Present day, 1.1 billion people face the lack of water; 1.3 billion people cannot access modern energy and 1.02 billion people are still starving. Meanwhile, the number of human population keeps increasing and this will induce the water, energy, and food scarcity in the future even worse. Increasing the stock or finding new alternative resources of water, energy and food individually is the most practical way to avoid the scarcity. Behind this improvement, it must be realized that these resources are connected each other. Water needs energy to be treated and distributed; in opposite way energy production requires water for cooling system or as the sources in hydropower plant. Food is in needed water and energy for growing, producing and delivering. Food can also become new energy source from biofuel but the food intensification will deteriorate water quality. Therefore, the integrated development and management, known as Water-Energy-Food (WEF) Nexus, is needed to reach the balance and optimal development. Fulfilling the human need faces another challenge when the climate change influences the availability of these resources. Many researchers report that climate change causes increase in the earth temperature alters the rainfall pattern and magnitude which affect the safe water availability. Further, it can affect the food and energy production. Taking an inappropriate use of water, energy and food will threaten the amount of resources itself. As it is a complex and complicated interconnection, it is difficult to determine the appropriate uses solely based on human judgment. Many researchers have developed computer models to simulate the correlation between each element and aid the decision maker. Due to its complexity, most of models only focus on one or two elements such as water-energy or water-food and put other element as the secondary parameter. This study provides overview of the WEF Nexus and inter-connections among the three elements. Furthermore, we will envision a development of an evaluation model that can simulate and optimize the use of water, energy and food efficiently under the climate change condition. If succeed, this model could be a decision support system for government or stakeholder to implement a regulation related to efficient use of water, energy and food.

This research study aims to examine who vulnerable people are on disaster & emergency situations in South Korea. There are various vulnerable people such as children, senior citizen, the disabled and foreigners. I choose foreigners who live in South Korea as vulnerable group among them because there would be no system and study for helping foreigners on the situations, comparing to other vulnerable groups. Foreigners' residents often could have accidents from disaster and emergency situations because they live in South Korea for long time and various places such as factory, farmland, fishery and so on. To solve these problems, we should be willing to cope with emergencies for foreigners’ residents. First of all, it is necessary that a variety of educations and promotions should be a prerequisite to foreign residents' easy access to safety. As well, revitalizing a variety of communities, we need to figure out a way to cope with emergent disasters. This study will present some preparations to solve the problems, as exhibited in the following. First, multilingual emergency disaster & emergency services applications. Second, foreign residents provide disaster & emergency related promotional media. Third, education and social institutions established disaster & emergency. Forth, selection foreign volunteer firefighters. The research being sought by this study is a set of findings that contribute to the development of practical and realistic policy recommendations which may be used for disaster & emergency management practitioners, as well as policy and decision makers at all level.

This study focuses on the effects of load height on the inelastic lateral buckling of doubly stepped I-beams. The effects of having compact and non-compact flanges are also covered by this study. Two sections are analyzed: one having compact flanges and web while the other section has a compact web and non-compact flanges. The loadings are limited to those having an inflection point of zero. Also, the three main locations for the loads analyzed would be at the top of the flange, at the shear and at the bottom flange. The nonlinear analysis is done using the finite element program, ABAQUS. Also, to take into consideration the effect of inelastic buckling, residual stresses and geometric imperfections are applied to the models made. The results of the analysis would then determine if the location of the loads has significant effects on the buckling strength of the stepped beams. Also, the results are compared to the results of previous studies involving the effects of load-height on prismatic beams. The final results are tabulated and conclusions and new design methods are provided.

Global climate change has made natural disasters become large-scale, diversified, and concentrated, causing social and economic damages one after another. The frequency of natural disasters and the scale of subsequent damages are continuously increasing and more than 90% of damages are caused by rainfall, wind speed, and snowfall. In particular, flood damage accounts for the greatest percentage of damage, which prompts us to prepare necessary preventive measures. Flood damage caused by river inundation often occurred in the past. Recently, however, inland flood damages, such as the inundation of Gangnam Station in 2011 and 2012, caused by urbanization have been increasing, which makes it necessary to simulate flood inundation and calculate the damages while considering the effect of inland inundation as well as river inundation. Accordingly, this study analyzed the inland inundation reduction effect through a simulation of flood inundation utilizing flood pumping stations in Anyang River. An economic analysis was also conducted. In addition, this study prepared/compared the flow inundation map based on the existence and operation of flood pumping stations during a localized heavy rainfall event and tried to analyze the economic feasibility by comparing the expected flood damage and the cost of flood pumping stations using Multi-dimensional Flood Damage Assessment. Through this study, results will be provided as reference data for qualitative flood inundation simulation and economic analysis of the basin where natural discharge of direct runoff is impossible and compulsive drainage is taking place.

Sewage Pipe Renewal (SPR) method rehabilitate pipeline by forming a PVC profile inside the pipe by using a winding machine without excavating the soil above the pipe which lowers the cost of the rehabilitation. This study will investigate the effects of varying the pipe’s diameter to its wall thickness ratio. The dimensions for the diameter and minimum wall thickness of the non-reinforced concrete pipe will be based from ASTM C14. The finite element analysis software, ABAQUS, will be used to model and perform the analysis for the composite pipes. To account for the soil-pipe interaction, soil springs will be used as the bedding support to hold the pipe in place. Additionally, three soil types will be used to compare the behavior of the pipe with different diameter to thickness ratios. The results from the finite element analysis will be shown in tables and plotted into graphs and a concluding remarks will be provided.

Detection of water bodies and their flow paths is elemental process of terrain analysis in any application related with surface water. Several algorithms have been proposed for automatic extraction of surface flow paths from Digital Elevation Models (DEMs) (e.g., O’Callaghan and Mark, 1984; Tarboton, 1997; Paik, 2008). While these algorithms have been widely applied, DEMs-based approaches have fundamental limitation in detecting water bodies. To resolve this issue, we propose a hybrid approach that utilizes DEMs and satellite imagery together. These dataset supplement each other’s weakness, providing extra information for better detection of water bodies and flow paths. The proposed approach is tested for the Geum River, showing successfully extraction of flow boundaries and more resonable flow paths within water bodies.

One of the best solutions for the deficiency of clean water, especially for developing countries, is rainwater disinfection. In the past decades a lot of studies have been made to develop photocatalytic processes using TiO2 determining the performance on their surface oriented photocatalysis. However, most of these researches failed to consider the economical aspect as well as the effectiveness on the disinfection to antibiotic resistance genes. On the other hand, due to the issues of climate change and increased impermeable layer in urban area, flooding prevention is the best solution in water management systems. To remedy these two problems, a roof-harvested rainwater storage system was designed. In addition, a breakthrough technique using a solar simulator with self-rotating TiO2 nanotubes, to apply a photocatalytic system in disinfecting storage rainwater harvested from roof, was established. Roof-harvested storage rainwater was analysed for TN, TP, SS and COD. Aside from these parameters, Escherichia coli (with multidrug resistant pB10 plasmid) was added to the sample. Samples were injected to the self-rotating TiO2 nanotube reactor system with exposure time of 0 to 360 min and 7 different setups. Results show that the developed system has increased disinfection properties compared to negative samples, though the presence of antibiotic resistant bacteria.

Storm water pollution has been the various concerns over the past decade. Decreasing the contamination levels of runoffs to the minimum accepted levels to protect the water quality of rivers, estuaries, streams, lakes, seas, and other bodies of waters have been the objectives of various storm water best management practices (BMP) implemented. BMPs has been augmented to existing water treatment facilities to provide additional resources for potable water usage. Novel filter materials are used to improve the performance of media filters and extend their capabilities to removing other pollutants such as organic/aromatic hydrocarbons and heavy metals. Among the novel materials being considered are photocatalyst nanoparticles coated into the sand media filter. Photocatalysts have been applied in the degradation of organic pollutants with the help of visible light irradiation. This paper describes the synthesis and use of nanoparticle–coated zeolite media filter to remove dissolved metals (Cu and Zn). Catalyst surface analysis revealed that the Cu and Zn were chemically adsorbed, and were transformed into its corresponding elemental forms.

Recently, Low Impact Development (LID) technology has been developed and used to collect, infiltrate, filter and confine runoff in order to enhance the storm water quality and to preserve the natural water cycle. In this study, two technologies were employed in order to treat runoff from an impervious surface such as a paved road and a parking lot. The infiltration trench which was constructed to manage stormwater runoff from a paved road abates and temporarily holds stormwater runoff and removes sediments and attached pollutants within the sub-surface structure prior to infiltration into the subsoils. On the other hand, the tree box filter which incorporates trees and other gardening plants to regulate and treat runoff drains the stormwater from a parking lot. The infiltration trench and tree box filter represent only 1% of the catchment area that they drain. This research was conducted to evaluate the hydrologic and water quality effects of the infiltration trench and tree box filter after LID. Storm event monitoring was conducted for the infiltration trench from May 2009 to August 2014 with a total of 38 storm events and 24 storm events in the tree box filter from July 2010 to July 2014. Hydrologic (i.e., total rainfall, antecedent dry day (ADD), runoff volume, etc.) and water quality (i.e. particulates, nutrients, organics, and heavy metals) parameters were analyzed before and after LID. The major findings of this study are as follows: The runoff before LID was discharged directly to the sewers and could lead to local flooding of transport systems and pollution to receiving waters during intense storm events. But, after LID the runoff was partially reduced for atleast 50% on the two (2) urban landuses. Furthermore, the pollutant concentration before LID was observed to be at high concentrations. However, it was reduced to an approximate of 60% after LID. With the combined processes of infiltration, filtration, retention and evapotranspiration that were provided by the infiltration trench and tree box filter, the runoff was partially reduced and a significant decrease in pollutant concentration has been observed. The results and findings of this study will help facilitate the LID for further application.

상수관은 급격한 기온 변화나 지진에 의한 지반의 변이 및 노후화에 의해 파단이 일어나게 된다. 관의 파단은 상수관망에서 발생할 수 있는 가장 흔한 파괴 상황 중 하나로 시스템으로 공급되는 전체 유량과 관망 내 수두 손실을 증가시킨다. 이러한 변화는 시스템 내에 설치된 압력 및 유량계의 측정값에 영향을 주며 사용성을 저하시킨다. 관 파괴 탐지가 지연되면 주위 지반의 액상화에 의해 싱크홀이 발생하게 되어 복구 시간 및 비용 (사회적 비용 포함)의 증가를 야기하기도 한다. 따라서, 관 파단의 정확하고 신속한 탐지가 필요하다. 본 연구에서는 공정관리 및 품질공학에서 적용되어온 통계적 공정관리 방법을 관 파단 탐지에 적용하였다. 시스템 내에 설치된 압력 및 유량계로부터 측정된 시계열 값을 과거 통계 값과 비교하여 관 파단 여부를 결정하였다. 실제 네트워크에서 수요량의 변동성을 고려해 발생시킨 압력 및 유량 자료를 이용하여 단변량과 다변량 방법을 포함, 총 여섯 가지 통계적 공정관리 방법의 성능을 비교하였다.