DEM-based river cross-section extraction and 1-D streamflow simulation for eco-hydrological modeling: a case study in upstream Hiikawa River, Japan

Designing for exceedance events consists in designing a continuous route for overland flow to deal with flows exceeding the sewer system’s capacity and to mitigate flooding risk. A review is carried out here on flood safety/hazard criteria, which generally establish thresholds for the water depth and flood velocity, or a relationship between them. The effects of the cross-section shape, roughness and slope of streets in meeting the criteria are evaluated based on equations, graphical results and one case study. An expedited method for the verification of safety criteria based solely on flow is presented, saving efforts in detailing models and increasing confidence in the results from simplified models. The method is valid for 0.1 m2/s 0.5 m2/s. The results showed that a street with a 1.8% slope, 75 m1/3s−1 and a rectangular cross-section complies with the threshold 0.3 m2/s for twice the flow of a street with the same width but with a conventional cross-section shape. The flow will be four times greater for a 15% street slope. The results also highlighted that the flood flows can vary significantly along the streets depending on the sewers’ roughness and the flow transfers between the major and minor systems, such that the effort detailing a street’s cross-section must be balanced with all of the other sources of uncertainty.

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A case study on deformation characteristics of a large cross-section tunnel passing through a soft-plastic layer with different spatial locations

Arabian Journal of Geosciences ◽

10.1007/s12517-021-06544-2 ◽

2021 ◽

Vol 14 (4) ◽

Author(s):

Qiuyang Hong ◽

Hongpeng Lai ◽

Yuyang Liu ◽

Rui Chen ◽

Cheng Liu ◽

...

Keyword(s):

Cross Section ◽

Plastic Layer ◽

Deformation Characteristics ◽

Large Cross Section ◽

Spatial Locations

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A Review of Numerical Simulations of Secondary Flows in River Bends

Water ◽

10.3390/w13070884 ◽

2021 ◽

Vol 13 (7) ◽

pp. 884

Author(s):

Rawaa Shaheed ◽

Abdolmajid Mohammadian ◽

Xiaohui Yan

Keyword(s):

Numerical Modeling ◽

Numerical Simulations ◽

Secondary Flow ◽

Cross Section ◽

Turbulence Models ◽

Main Flow ◽

Secondary Flows ◽

River Bends ◽

River Cross Section ◽

River Bend

River bends are one of the common elements in most natural rivers, and secondary flow is one of the most important flow features in the bends. The secondary flow is perpendicular to the main flow and has a helical path moving towards the outer bank at the upper part of the river cross-section, and towards the inner bank at the lower part of the river cross-section. The secondary flow causes a redistribution in the main flow. Accordingly, this redistribution and sediment transport by the secondary flow may lead to the formation of a typical pattern of river bend profile. It is important to study and understand the flow pattern in order to predict the profile and the position of the bend in the river. However, there are a lack of comprehensive reviews on the advances in numerical modeling of bend secondary flow in the literature. Therefore, this study comprehensively reviews the fundamentals of secondary flow, the governing equations and boundary conditions for numerical simulations, and previous numerical studies on river bend flows. Most importantly, it reviews various numerical simulation strategies and performance of various turbulence models in simulating the flow in river bends and concludes that the main problem is finding the appropriate model for each case of turbulent flow. The present review summarizes the recent advances in numerical modeling of secondary flow and points out the key challenges, which can provide useful information for future studies.

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History, Colonialism, and Archival Methods in Socio-Hydrological Scholarship: A Case Study of the Boerasirie Conservancy in British Guiana

World ◽

10.3390/world1030015 ◽

2020 ◽

Vol 1 (3) ◽

pp. 205-215

Author(s):

Joshua Mullenite

Keyword(s):

Environmental History ◽

Cross Section ◽

Science And Technology Studies ◽

Model Development ◽

Human Geography ◽

Hydrological Models ◽

British Guiana ◽

Current Role

In this article, I review a cross-section of research in socio-hydrology from across disciplines in order to better understand the current role of historical-archival analysis in the development of socio-hydrological scholarship. I argue that despite its widespread use in environmental history, science and technology studies, anthropology, and human geography, archival methods are currently underutilized in socio-hydrological scholarship more broadly, particularly in the development of socio-hydrological models. Drawing on archival research conducted in relation to the socio-hydrology of coastal Guyana, I demonstrate the ways in which such scholarship can be readily incorporated into model development.

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Decision Support for the (Inter-)Basin Management of Water Resources Using Integrated Hydro-Economic Modeling

Hydrology ◽

10.3390/hydrology8010042 ◽

2021 ◽

Vol 8 (1) ◽

pp. 42

Author(s):

Gerald Norbert Souza da Silva ◽

Márcia Maria Guedes Alcoforado de Moraes

Keyword(s):

Decision Support ◽

Water Resources ◽

Water Allocation ◽

Hydrological Modeling ◽

Well Being ◽

Water Transfer ◽

Economic Modeling ◽

Trade Offs ◽

Study Results

The development of adequate modeling at the basin level to establish public policies has an important role in managing water resources. Hydro-economic models can measure the economic effects of structural and non-structural measures, land and water management, ecosystem services and development needs. Motivated by the need of improving water allocation using economic criteria, in this study, a Spatial Decision Support System (SDSS) with a hydro-economic optimization model (HEAL system) was developed and used for the identification and analysis of an optimal economic allocation of water resources in a case study: the sub-middle basin of the São Francisco River in Brazil. The developed SDSS (HEAL system) made the economically optimum allocation available to analyze water allocation conflicts and trade-offs. With the aim of providing a tool for integrated economic-hydrological modeling, not only for researchers but also for decision-makers and stakeholders, the HEAL system can support decision-making on the design of regulatory and economic management instruments in practice. The case study results showed, for example, that the marginal benefit function obtained for inter-basin water transfer, can contribute for supporting the design of water pricing and water transfer decisions, during periods of water scarcity, for the well-being in both basins.

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Logging Optimization and Data Analysis Enabling Bypass Pay Identification and Hydrocarbon Quantification with Advanced Pulsed Neutron Behind Casing

10.2118/208512-ms ◽

2021 ◽

Author(s):

Sviatoslav Iuras ◽

Samira Ahmad ◽

Chiara Cavalleri ◽

Yernur Akashev

Keyword(s):

Cross Section ◽

Pore Space ◽

High Energy ◽

Elastic Cross Section ◽

Gas Production ◽

Donets Basin ◽

Lithology Identification ◽

Open Hole ◽

Pulsed Neutron

Abstract Ukraine ranks the third largest gas reserves in Europe. Gas production is carried out mainly from the Dnieper-Donets Basin (DDB). A gradual decline in reserves is forcing Ukraine to actively search for possible sources to increase reserves by finding bypassed gas intervals in existing wells or exploration of new prospects. This paper describes 3 case studies, where advanced pulsed neutron logging technology has shown exceptional value in gas-bearing layer identification in different scenarios. The logging technology was applied for formation evaluation. The technology is based on the neutron interaction with the minerals and the fluids contained in the pore space. The logging tool combines measurements from multiple detectors and spacing for self-compensated neutron cross-capture section (sigma) and hydrogen index (HI), and the Fast Neutron Cross Section (FNXS) high-energy neutron elastic cross section rock property. Comprehensive capture and inelastic elemental spectroscopy are simultaneously recorded and processed to describe the elemental composition and the matrix properties, reducing the uncertainties related to drilling cuttings analysis, and overall, the petrophysical evaluation combined with other log outputs. The proposed methodology was tested in several wells, both in open hole and behind casing. In the study we present its application in three wells from different fields of the DDB. The log data acquisition and analysis were performed across several sandstone beds and carbonates formation with low porosities (<10%), in various combinations of casing and holes sizes. The results showed the robustness and effectiveness of using the advanced pulsed neutron logging (PNL) technologies in multiple cases: Case Study A: Enabling a standalone cased hole evaluation and highlighting new potential reservoir zones otherwise overlooked due to absence of open hole logs. Case Study B: Finding by-passed hydrocarbon intervals that were missed from log analysis based on conventional open hole logs for current field operator. Case Study C: Identifying gas saturated reservoirs and providing solid lithology identification that previously was questioned from drilling cuttings in an unconventional reservoir.

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