Current Practice in Fluvial Geomorphology - Dynamics and Diversity最新文献

{"title":"River Plume in Sediment-Laden Rivers","authors":"L. Yilmaz","doi":"10.5772/intechopen.90089","DOIUrl":"https://doi.org/10.5772/intechopen.90089","url":null,"abstract":"Fractal dimension, which is a measure for the degree of complexity or that of fractals, is given for the erosion and sedimentation of fluvial beds. An alternative to fractal dimension is ht-index, which quantifies complexity in a unique way while sediment particles begin to move if a situation is eventually reached when the hydrodynamic force exceeds a certain critical value. Back to question, the physical meaning of fractal dimension is that many natural and social phenomena are nonlinear rather than linear, and are fractal rather than Euclidean. We need a new paradigm for studying our surrounding phenomena, not Newtonian physics for simple systems, but complexity theory for complex systems, not linear mathematics such as calculus, Gaussian statistics, and Euclidean geometry, but online mathematics including fractal geometry, chaos theory, and complexity science in general.","PeriodicalId":210504,"journal":{"name":"Current Practice in Fluvial Geomorphology - Dynamics and Diversity","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-01-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116474654","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Introductory Chapter: Current Practice in Fluvial Geomorphology: Research Frontiers, Issues and Challenges","authors":"K. Ghosh, S. Mukhopadhyay","doi":"10.5772/intechopen.89687","DOIUrl":"https://doi.org/10.5772/intechopen.89687","url":null,"abstract":"Over the last one and half century, the prime interest area of fluvial geomorphology has meandered from global system and local process [1]. Returning to the discipline’s critical role in regional-to-local scale problem solving [2], fluvial geomorphology has experienced awesome progress in understanding of the trends and patterns of riverine landscape dynamics [3, 4]. However, it is necessary to understand the current research interests of the fluvial geomorphologists amid the global challenges. In this direction, all regular research articles allied to fluvial geomorphology in one of the leading geomorphological journals, Geomorphology (ISSN: 0169-555X), are scrutinized for 2018. Among all the 329 regular articles published in 24 volumes (300–323) during 2018, 112 (34%) are within the discipline of fluvial geomorphology. Afterward, the subject matters of the selected articles are grouped into 10 broad themes (Table 1 and Figure 1). As this review work considers one single globally recognized journal and takes a single year as sample therefore, the result may not necessarily highlight all the current research progresses but obviously could detect the directions in which the subject is developing/inclining. While going through the title and abstracts of the 112 sampled research papers, we have grouped them quite readily into 10 broad themes (Figure 1) which are addressed further in turn by the focal words (Table 1). The theme ‘Fluvial sediment environment’ had the greatest number of papers counting 25 (22%); 20 (18%) fall within ‘Holocene Fluvial Chronology (Historical Channel change, Stratigraphy, Paleo Hydrology)’, 18 (16%) in ‘Modelling fluvial environment and application of advanced techniques’, and 11 (10%) in ‘Anthropogenic Controls’. ‘Fluvial morphology (Processes and forms)’ and ‘fluvial hydraulics’ include 7 (6%) articles each, while 6 (5%) fall under ‘(Neo)tectonics’, and ‘Gully and hill slope erosion’. Apart from these, 5 articles (4%) addressed Riverine ecology and 7 (6%) fall within ‘crosscutting fields’ (i.e. fluvial geomorphology in association with other branches of geomorphology). It is interesting to note that there is no article pertaining to ‘river management and restoration’ which is one of the focal themes in present research frontiers of fluvial geomorphology [5]. In consideration of the popular remark ‘Geomorphology is largely an intellectual child of the Twentieth Century’ [6], the review results show that fluvial geomorphology is continuously refocusing on process and forms and thereby making interface with other disciplines like sedimentology. Moreover, much of the research articles we have revisited for the present assessment are basically geomorphological","PeriodicalId":210504,"journal":{"name":"Current Practice in Fluvial Geomorphology - Dynamics and Diversity","volume":"44 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-01-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126636946","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Remote Sensing and River Basin Management: An Expository Review with Special Reference to Southwest Nigeria","authors":"Adewole Adedayo Oreoluwa, Eludoyin Adebayo Oluwole","doi":"10.5772/intechopen.88681","DOIUrl":"https://doi.org/10.5772/intechopen.88681","url":null,"abstract":"This chapter is part of the focus on the development in river basin management, and its specific objective is to provide an expository review of drainage basin morphometry and the relevance of remote sensing technology, especially for locations in developing countries, where sophisticated remote sensing technology are either expensive or challenged by limited professionals. The chapter is divided into six subsections, treating issues on remote sensing, drainage density and presenting specific case study, among others. The study reveals that remote sensing technology is efficient for providing decision support system for both gauged and ungauged river basins, and that freely available remote sensing data can efficiently fill the data gaps in many developing countries. It however warned on the need to consider variations in sensors capacity and mission as important attributes that can generate different spatial radiometric issues which may negatively affect the quality of the results. It concluded that researchers on drainage basin analysis in developing countries will benefit immensely from the freely available remote sensing data in the region.","PeriodicalId":210504,"journal":{"name":"Current Practice in Fluvial Geomorphology - Dynamics and Diversity","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-10-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129486168","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of the Evapotranspiration of Thornthwaite and of Penman-Monteith in the Estimation of Monthly Streamflows Based on a Monthly Water Balance Model","authors":"M. M. Portela, J. F. Santos, T. D. C. Studart","doi":"10.5772/intechopen.88441","DOIUrl":"https://doi.org/10.5772/intechopen.88441","url":null,"abstract":"The river discharge monitoring networks are generally sparser and more recent than those of other hydrological variables, like rainfall or temperature. Further-more, most of the streamflow series show long periods without records and several gaps, thereby limiting their use. Hydrological modeling provides a tool to overcome the poor quality of the streamflow data. However, its applicability to fill in the gaps or increase the time spans of the existing series and also to estimate streamflows at ungauged catchments depends on the simplicity and on the few data requirements of the approach selected, which makes the water balance models suitable choices. In the previous scope, the role of evapotranspiration in a water balance model was investigated for Portugal based on two approaches: a more complex with more data requirements, the Penman-Monteith method, and a very simple one only based on temperature data, the Thornthwaite method. The results showed that the monthly streamflows estimated based on any of the previous evapotranspiration models are almost the same. In fact, when the differences between the two models are higher, the surface runoff process is no longer controlled by the evapotranspiration but instead by the absence of rainfall and by the dryness of the soil.","PeriodicalId":210504,"journal":{"name":"Current Practice in Fluvial Geomorphology - Dynamics and Diversity","volume":"41 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132154628","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Modeling River Morphodynamic Process Using a Depth-Averaged Computational Model and an Application to a Mountain River","authors":"Yafei Jia, Yaoxin Zhang, K. Yeh, C. Liao","doi":"10.5772/INTECHOPEN.86692","DOIUrl":"https://doi.org/10.5772/INTECHOPEN.86692","url":null,"abstract":"Bank erosion is a dominant river morphodynamic process resulting in encroaching valuable farming land and channel migration. Prediction of bank erosion and channel migration requires understanding of the morphodynamics of the entire river system. Numerical modeling is an ideal method for this task. How-ever, models with full capabilities and applications on complex real-world problems are rare. In this study the finite element-based computational model, CCHE2D, and its flow, sediment transport, and bank erosion modules are introduced. The model is capable of simulating unsteady flows with nonuniform sediment transport and cohesive/non-cohesive material bank erosion. The effects of helical secondary current on sediment transport induced by flow curvatures are reflected in both bed load and suspended sediment formulations. This model is validated using multiple sets of experimental data and applied to bank erosion problems of the Chuoshui River, a real-world mountain river in Taiwan. Characterized by typhoon floods, steep channel slopes, and high sediment load and mobility, this river often exhibits a braided pattern consisting of multiple curved channels. Channel bed change and bank erosion caused by 10 years of typhoon floods in a selected reach have been simulated, and the computed bank erosion results agreed with the field observation.","PeriodicalId":210504,"journal":{"name":"Current Practice in Fluvial Geomorphology - Dynamics and Diversity","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116323034","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Overview of Hydrological Dynamics and Geomorphological Aspects of the Amazon Region Rivers to Characterize Fluvial Sensitivity to Oil Spills","authors":"P. Silva, F. Miranda, C. Beisl, L. Landau, Alexandre Evsukoff","doi":"10.5772/INTECHOPEN.86592","DOIUrl":"https://doi.org/10.5772/INTECHOPEN.86592","url":null,"abstract":"This chapter presents a collection of studies performed in the Amazon region that includes thematic products portraying its fluvial sensitivity to oil spills. The research addresses the intense Amazonian seasonal dynamics, as well as the environmental peculiarities of this singular ecosystem. Periodic changes caused by natural phenomena have a significant impact on not only flooded alluvial plains and riverine habitats but also on petroleum exploration, production, and transportation activities. Therefore, the implementation of tools to assess the potential impact of oil spills in the Amazonian rivers must be adjusted to the local conditions. The main deliverables of the research are (1) fluvial oil spill sensitivity index maps contemplating each phase of the hydrological cycle (low water, high water, receding water, and rising water), (2) a computational method to represent fluctuations of the seasonal inundation, and (3) a risk analysis method using linguistic rules for the construction of a risk matrix.","PeriodicalId":210504,"journal":{"name":"Current Practice in Fluvial Geomorphology - Dynamics and Diversity","volume":"53 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-06-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129460008","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Experimental Study of Local Scour around Side-by-Side Bridge Piers under Ice-Covered Flow Conditions","authors":"M. R. Namaee, J. Sui, Peng Wu","doi":"10.5772/INTECHOPEN.86369","DOIUrl":"https://doi.org/10.5772/INTECHOPEN.86369","url":null,"abstract":"A precise prediction of maximum scour depth (MSD) around piers under ice-covered conditions is crucial for the safe design of the bridge foundation. Due to the lack of information for local scour under ice-covered flow condition, it is extremely hard to give proper estimation of MSD. In the current study, a set of flume experiments were completed to investigate local scour around four pairs of circular bridge piers with nonuniform bed materials under open channel, smooth and rough ice cover conditions. Three different bed materials with median particle size of 0.47, 0.50, and 0.58 mm were used to simulate natural river conditions. Regardless of pier size, the maximum scour depths were observed in front of the piers under all flow conditions. Additionally, a smaller pier size and a larger space between piers yield a smaller scour depth. Results showed that the maximum scour depth decreases with increase in the grain size of armor layer. The distribution of vertical velocity shows that the strength of downfall velocity is the greatest under rough ice cover. Empirical equations were developed to estimate the maximum scour depth around side-by-side bridge piers under both open-channel and ice-covered flow conditions.","PeriodicalId":210504,"journal":{"name":"Current Practice in Fluvial Geomorphology - Dynamics and Diversity","volume":"134 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-05-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123414499","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}