scholarly journals Sediment budget analysis of the Guayas River using a process-based model

2018 ◽  
Author(s):  
Pedro D. Barrera Crespo ◽  
Erik Mosselman ◽  
Alessio Giardino ◽  
Anke Becker ◽  
Willem Ottevanger ◽  
...  

Abstract. The Equatorial Daule and Babahoyo rivers meet and combine into the tidal Guayas River, which flows into the largest estuary on the Pacific coast of South America. The city of Guayaquil, located along the Guayas, is the main port of Ecuador but, at the same time, the planet's fourth most vulnerable city to future flooding due to climate change. Fluvial sedimentation, which has increased in the recent years, is seen as one of the factors contributing to the risk of flooding. The planning and design of effective mitigation measures requires a good understanding of the causes which have led to the current hazards. In this study, the process-based Delft3D FM model was used in order to explain the dominant processes in the river and the effects that past interventions along the river and its estuary have had in the overall sediment budget. Additionally, a simulation including sea level rise was used in order to understand the possible future impact of climate change on the sediment budget. Results indicate that the increased import of marine sediment is the result of the recent increase in tidal asymmetry due to land reclamation and a decrease of episodic flushing by river floods due to upstream dam construction. This is in contrast with the local perception of the problem, which ascribes sedimentation to deforestation in the upper catchment. Only the deposition of silt and clay in connected stagnant water bodies could perhaps be ascribed to upstream deforestation.

2019 ◽  
Vol 23 (6) ◽  
pp. 2763-2778 ◽  
Author(s):  
Pedro D. Barrera Crespo ◽  
Erik Mosselman ◽  
Alessio Giardino ◽  
Anke Becker ◽  
Willem Ottevanger ◽  
...  

Abstract. The equatorial Daule and Babahoyo rivers meet and combine into the tidal Guayas River, which flows into the largest estuary on the Pacific coast of South America. The city of Guayaquil, located along the Guayas, is the main port of Ecuador but, at the same time, the planet's fourth most vulnerable city to future flooding due to climate change. Sedimentation, which has increased in recent years, is seen as one of the factors contributing to the risk of flooding. The cause of this sedimentation is the subject of the current research. We used the process-based Delft3D FM model to assess the dominant processes in the river and the effects that past interventions along the river and its estuary have had on the overall sediment budget. Additionally, a simulation including sea level rise was used in order to understand the possible future impact of climate change on the sediment budget. Results indicate an increase in tidal asymmetry due to land reclamation and a decrease in episodic flushing by river floods due to upstream dam construction. These processes have induced an increased import of marine sediment potentially responsible for the observed sedimentation. This is in contrast with the local perception of the problem, which ascribes sedimentation to deforestation in the upper catchment. Only the deposition of silt and clay in connected stagnant water bodies could perhaps be ascribed to upstream deforestation.


2021 ◽  
Author(s):  
Barbara Vojvodíková ◽  
Jiří Kupka ◽  
Adéla Brázdová ◽  
Radim Fojtík ◽  
Iva Tichá

To increase their resilience to climate change, cities are looking to apply elements of urban environmental acupuncture. The essence of such measures is many smaller sites that is functioning as mitigation measures. Many of these small places then create a large overall effect. The advantage of these small-scale measures is that they can be in densely populated areas The assessment tool described in this paper is designed for city representatives and is an aid to assess the suitability of applying a particular measure based on the parameters described. The evaluation itself then helps to decide whether the solution is suitable for a particular site or whether any of the parameters need to be adjusted to make it suitable, or whether it would be appropriate to change the proposed solution. The intention of the evaluation is not to assess the technical solution but relies primarily on the location, long-term (especially financial) sustainability and acceptance by the citizens of the city. The paper presents an example of the application of the evaluation to four sites in city Liptovský Mikuláš, describing the results and identifying parameters that can be improved to ensure the urban environmental acupuncture is accepted by citizens and thus future-proofed.


2021 ◽  
Vol 13 (18) ◽  
pp. 10254
Author(s):  
Anton Galich ◽  
Simon Nieland ◽  
Barbara Lenz ◽  
Jan Blechschmidt

Bicycle usage is significantly affected by weather conditions. Climate change is, therefore, expected to have an impact on the volume of bicycle traffic, which is an important factor in the planning and design of bicycle infrastructures. To predict bicycle traffic in a changed climate in the city of Berlin, this paper compares a traditional statistical approach to three machine learning models. For this purpose, a cross-validation procedure is developed that evaluates model performance on the basis of prediction accuracy. XGBoost showed the best performance and is used for the prediction of bicycle counts. Our results indicate that we can expect an overall annual increase in bicycle traffic of 1–4% in the city of Berlin due to the changes in local weather conditions caused by global climate change. The biggest changes are expected to occur in the winter season with increases of 11–14% due to rising temperatures and only slight increases in precipitation.


2017 ◽  
Vol 7 (2) ◽  
Author(s):  
Aris Widodo

Jakarta is hit by a tidal flood every year and cause some loss for the city. Beside that flood caused by sea level rise, the city risk on sinking is higher because of land subsidence problem. Without any significant action, it is predicted that Jakarta will face USD 521 million loss risks on 2050 caused by flood. To overcome the sinking problem, Indonesian government plays an active role on the international action to combat climate change. In addition, Indonesian government also implements NCICD project, in which create giant sea wall and land reclamation on the Jakarta Bay.  However, the land reclamation raises an argument that it would create an environment disaster for the city. Because of that, it is suggested that Jakarta should only create a sea wall without land reclamation. Moreover, Jakarta government also should ensure that Spatial City Planning and New Rule on ground water extraction are well implemented so the land subsidence in the city is stopped.


2019 ◽  
Vol 16 (1-2) ◽  
pp. 153-179
Author(s):  
Angie Chung ◽  
Johng Song ◽  
Carolyn Choi

Based on the experiences of a Koreatown scholar, the executive director of a Koreatown nonprofit, and a longtime resident student, the article advocates for greater attention to the complex and dynamic power structures of ethnic enclaves in community-academic partnerships. We discuss the changing landscapes of Koreatown as the global nexus of the Pacific Rim economy, the city of Los Angeles’s urban redevelopment plans, and growing diversity and inequality. Programs that aim to engage effectively with ethnic communities must reassess how knowledge is produced and conveyed, how we structure partnerships within stratified communities, and how to grow from issue-based partnerships to broader communities of interest.


Author(s):  
Barley Norton

This chapter addresses the cultural politics, history and revival of Vietnamese court orchestras, which were first established at the beginning of the Nguyễn dynasty (1802–1945). Based on fieldwork in the city of Hue, it considers the decolonizing processes that have enabled Vietnamese court orchestras to take their place alongside other East Asian court orchestras as a display of national identity in the global community of nations. The metaphor of ‘orchestrating the nation’ is used to refer to the ways in which Vietnamese orchestras have been harnessed for sociopolitical ends in several historical periods. Court orchestras as heritage have recourse to a generic, precolonial past, yet they are not entirely uncoupled from local roots. Through a case-study of the revival of the Nam Giao Sacrifice, a ritual for ‘venerating heaven’, the chapter addresses the dynamics of interaction and exchange between staged performances of national heritage and local Buddhist and ancestor worship rituals. It argues that with growing concern about global climate change, the spiritual and ecological resonances of the Nam Giao Sacrifice have provided opportunities for the Party-state to reassert its position as the supreme guardian of the nation and its people.


Climate ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 34
Author(s):  
Catarina C. Rolim ◽  
Patrícia Baptista

Several solutions and city planning policies have emerged to promote climate change and sustainable cities. The Sharing Cities program has the ambition of contributing to climate change mitigation by improving urban mobility, energy efficiency in buildings and reducing carbon emissions by successfully engaging citizens and fostering local-level innovation. A Digital Social Market (DSM), named Sharing Lisboa, was developed in Lisbon, Portugal, supported by an application (APP), enabling the exchange of goods and services bringing citizens together to support a common cause: three schools competing during one academic year (2018/2019) to win a final prize with the engagement of school community and surrounding community. Sharing Lisboa aimed to promote behaviour change and the adoption of energy-saving behaviours such as cycling and walking with the support of local businesses. Participants earned points that reverted to the cause (school) they supported. A total of 1260 users was registered in the APP, collecting more than 850,000 points through approximately 17,000 transactions. This paper explores how the DSM has the potential to become a new city service promoting its sustainable development. Furthermore, it is crucial for this concept to reach economic viability through a business model that is both profitable and useful for the city, businesses and citizens, since investment will be required for infrastructure and management of such a market.


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