Urbanization has been identified as one of the issues with the greatest environmental impacts on water resources. This study aims to make an environmental diagnosis of urban water management with a ...systematic approach in a basin with great hydrogeological complexity. We have analyzed urban water management in the Langueyú basin, Argentina, in the period comprehended between 1940 and 2015 in which the city has had a disordered urban growth. It showed that the lack of integrated management together with urban expansion have resulted in a process of building densification and infrastructure that favors the recurrence and magnitude of exceptional hydrological events. This has been accompanied by a spatial displacement of these events and a lack of sanitary services with the same sense of urbanization. It was also demonstrated that the lack of integrated water management this not only had consequences on the Tandil city services associated with the urban hydrological cycle, but also on the quality of its surface water resources (contamination of streams in its urban section) and groundwater (elevation of nitrates levels in water from wells water supply). The absence of a systemic approach to the problem has not considered the relationships between the subsystems involved in water management. This management has been based mainly on the application of structural measures. The main non-structural measure carried out has been to expand the regulations and some neighbor's struggle movements. Other non-structural measures promoted by several actors involved in urban water management, such as authorities, should be carried out in order to raise awareness amongst the population on the importance of water resource protection, especially in areas with hydrogeological limitations.
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•Urban water management (UWM) is an organizing axis of space.•Urban water cycle includes different subsystems closely and complexly linked.•UWM should have a systemic approach that is necessary to address that complexity.•Structural measures only are not enough for a sustainable UWM.•Sustainable UWM requires non-structural measures with different stakeholders.
Flood disasters have appeared more frequently in recent years because of climate change and urbanization, and Integrated Flood Risk Management (IFRM) has emerged as an effective method to reduce ...damage from these floods. This research studies IFRM methods in three aspects: flood risk identification of high-risk areas, flood risk assessment to quantify economic losses, and flood risk management to identify structural measures with the greatest engineering benefits. These methods were applied to Beijing as a case study, and the results showed that the Zuoan-Road area was a high-risk area with economic losses ranging from 0.7 million to 35.9 million euros over different return periods. There are five structural measures in Zuoan-Road area, with engineering benefits ranging from 0.97 to 1.60 over different return periods, and the one with the greatest engineering benefits had a fifty-year return period. The results of this research can be used to support urban flood risk management in Beijing.
•Engineering Management mostly reduces flood risk through structural measures, but doesn’t consider the engineering benefit.•Integrated flood risk management can achieve a better engineering benefit than engineering management.•Flood economic losses and engineering benefits of structure measures can be calculated by integrated flood risk management.•A case study in Beijing was analyzed and the structure measure with greatest engineering benefits was obtained.
We introduce a class of networks formed by randomly interconnected cliques, with prescribed distribution of clique sizes and density of inter-clique connections. For these random networks of cliques, ...we determine the conditions for existence of a giant component and provide analytical expressions for clustering coefficients and assortativity. Also, we estimate their modularity and numerically find the average distance between nodes. As an application to real systems, we successfully compare our analytical predictions with the statistical structural properties of an intra-generational kinship (sibling and spouse) network built from genealogical data. The present model provides a tool for constructing networks with controlled structure, in particular, displaying small-world features.
Flood risk and its reduction in China Kundzewicz, ZW; Su, Buda; Wang, Yanjun ...
Advances in water resources,
August 2019, 2019-08-00, 20190801, Letnik:
130
Journal Article
Recenzirano
•Floods in China often cause annual loss in excess of 10 billion US$.•Flood risk has grown in many places in China and is likely to grow further in the future.•Floods of a given return period in the ...reference interval are projected to become more frequent in much of China.•There is a strong link between climate variability and abundant humidity in China.
Despite massive flood protection efforts in China, undertaken since the ancient times, disastrous floods continue to plague the country. In this paper, we discuss changes in flood hazard and flood risk in China. First, we review published results (including our own works) on change detection in observed records of intense precipitation, high river flow and flood damage in China. We provide information on essential features of extreme floods in last decades – floods on large rivers, urban floods, and flash floods. Next, we review available projections for the future (including our own results), related to intense precipitation, high river flow and flood damage in China. We try to interpret the difference in flood hazard projections obtained in various publications. Since the spread of river flood hazard projections is large, projections have to be interpreted with caution, because of the impact on decisions related to climate change adaptation, flood risk reduction, and water resources management. We review flood risk reduction strategies in China, focusing on the present situation and division of responsibilities. China has embarked upon an ambitious and vigorous task to improve flood preparedness, by both structural (“hard”) defences, such as: dikes, dams and flood control reservoirs, and diversions, as well as non-structural (“soft”) measures: spatial planning and zoning; watershed management (source control), flood forecasting and warning systems; and awareness raising. The strategy of flood mitigation includes flood retention and urban water management to alleviate the burden of flash and urban flooding.
Self-compacting concrete has the advantages of high fluidity, high uniform density, and low porosity. To promote the engineering application of self-compacting concrete, this article studies the ...axial compression test of ten square steel tube self-compacting concrete columns. The effects of design parameters such as different grades of concrete strength and internal structures of circular steel tubes, square steel tubes, and H-shaped steel on the mechanical properties of self-compacting fly ash concrete filled square steel tube columns are studied. The failure mode, characteristic load and characteristic displacement, ductility, and energy dissipation capacity of each specimen are analyzed. On the basis of the test, the finite element analysis model of steel tube self-compacting concrete column is established, and the test results and simulation results are compared and analyzed. The results show that: the failure mode of the square steel tube specimen is the multilayer middle and upper ring buckling failure. Internal structural measures of square steel tube and H-shaped steel can improve the bearing capacity, ductility, and energy dissipation capacity of the specimen. It is not recommended to use the specimen with an outer square and an inner circle design. The results of the finite element simulation have a high degree of matching with the test results, which intuitively reflects the changes in force of each component.
•The cause of fatigue failure in steel wire rope suspenders on suspension bridges has been identified.•The recommended approach of utilizing auxiliary cables is successful in decreasing ...tensile-bending fatigue stress levels.•These discoveries are significant for guiding the development and upkeep of comparable infrastructure ventures.
In consideration of the significant impact of train loads on the fatigue of suspenders in railway bridges, this paper focuses on the first railway suspension bridge in China − the Jinsha River Railway Suspension Bridge. The study analyzes the force characteristics and bending failure features of the steel wire ropes in railway suspension bridges, aiming to provide insights into the design of such structures. Firstly, a finite element model of the Jinsha River Railway Suspension Bridge is established in this paper. The natural frequencies are analyzed and compared with on-site measurements to validate the accuracy of the finite element model. Secondly, the tension force amplitude and angular displacement amplitude of the suspenders are analyzed under design loads, and the failure characteristics of the cables are experimentally examined. Subsequently, a wear fatigue test for steel wire rope is designed, evaluating the fatigue life of the suspender in the bridge. The computational results are compared with experimental data to validate their accuracy. Finally, structural measures to reduce the bending fatigue of railway suspension bridge suspenders are proposed to ensure their safety during the service life. The study reveals that the presence of bending stress exacerbates the fatigue failure of suspension cables in railway suspension bridges, with the failure mode identified as fatigue failure due to the tension-bending-wear coupling effect. Furthermore, our findings indicate that the implementation of auxiliary cables can reduce the displacement differential at both ends of the suspension cables by approximately 4/5, and decrease the axial tensile stress amplitude by about 3/4. Consequently, this significantly enhances the fatigue life of the suspension cables.
Business process modeling is one of the main tools of the BPM (Business Process Management) concept. With the help of business process modeling, business scenarios can be presented in the form of ...graphical models that can be easily understood by both information technology (IT) professionals and non-IT professionals – business analysts, software customers, department heads, top managers, and other stakeholders interested in business process improvement. Business process improvement is usually done through the automation of activities, which were identified as “bottlenecks” after analysis. However, it is possible to analyze a business process model only if it is clear and correct in terms of compliance with both the notation used and the real business process it depicts. This paper considers the analysis of BPMN (Business Process Model and Notation) business process model structural measures. It is assumed that business process models, which by their structural features violate rules of business process modeling, are neither understandable nor suitable for further work with them, which also can lead to various errors occurring at the stage of business process analysis, as well as at the stage of its improvement and implementation of proposed changes, i.e., during development, testing and maintenance of distinct software components, information system modules or BPM-system scenarios that ensure business process execution. Therefore, in this paper, we propose to identify the main elements of BPMN business process models and their structural measures that affect models’ understandability and maintainability and could be sources of errors. Considering selected measures, it is proposed to calculate respective values for a large collection of BPMN business process models, and then study compliance with theoretical business process modeling guidelines on practice when real business process models are designed. In order to provide efficient storage and processing of a large collection of BPMN business process models data, there were developed a database, and a software component. Results of analysis of BPMN business process model structural measures obtained using developed database and software component are demonstrated and discussed. The conclusion is made, as well as future research directions in this field are formulated.
Communities are being menaced by floods since ages. Flood occurrence not only imposes loss to the infrastructure and property but it also claims thousands of lives and leave millions homeless. Floods ...occur due to hydro-metrological and natural factors, however in recent years, human intervention has added new dimensions to it. South Asia's geography makes it susceptible to natural disasters and the most flood vulnerable regions in the world. In addition to this, countries in this region exhibit a high level of vulnerability unfortunately due to lack of resources, namely adaptive as well as coping capacities. Pakistan in particular, has a long history of floods. The country has witnessed almost 19 major flood events resulting into a cumulative flooding of over 594,700 km2 area with 166,075 villages affected and a total direct cumulative losses to the tune of about US $ 30 billion that ended up into the loss of 10,668 precious lives in the past 60 years. However, the floods of 2010 and 2011 were the most devastating. The national flood policy has been enhanced through several federal and provincial acts since the country came into existence. Unfortunately, there has not been reported any major reduction in the flood-to-damage ratio. Herein a brief review has been carried out that ponders on the current state of knowledge of the topic, particularly the nature of flood in the South Asian region, mainly Pakistan.
Risk analysis and appraisal of the benefits of structural flood risk management measures such as embankments is well established. Here, a method to quantify, over extended timescales, the ...effectiveness of non-structural measures such as land use spatial planning, insurance and flood resilient construction is presented. The integrated approach couples socio-economic and climate change scenarios with long term land use modelling and flood risk analysis to generate maps and time series of expected annual damages. The analysis has been applied on a case study in the Thames Estuary in the UK. Stakeholders helped develop a number of scenarios that might lead to substantial changes in existing planning and insurance policies in the UK. The effectiveness of these changes was analysed and showed the substantial benefits in terms of reduction of future flood risks that are achievable with changes in planning policy, financial incentives and resilient property construction in the floodplain. Moreover, the reward can be increased through earlier action. Subsequently, the benefits of a range of policies are explored under the UK Foresight socio-economic scenarios. Different structural and non structural flood management interventions are tested and the results demonstrate that despite the potential for large increases in flood risk in the Thames Estuary, in all scenarios substantial flood risk reductions are possible. The effectiveness of non-structural measures is however sensitive to socio-economic changes and governance arrangements. The analysis described here will help to identify portfolios of non-structural and structural options that are robust to uncertainties.
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