scholarly journals Tsunami damage reduction performance of a mangrove forest in Banda Aceh, Indonesia inferred from field data and a numerical model

2010 ◽  
Vol 115 (C6) ◽  
Author(s):  
H. Yanagisawa ◽  
S. Koshimura ◽  
T. Miyagi ◽  
F. Imamura
Keyword(s):  
Numerical Model ◽  
Mangrove Forest ◽  
Field Data ◽  
Damage Reduction ◽  
Tsunami Damage ◽  
Banda Aceh

Developing Fragility Functions for Tsunami Damage Estimation Using Numerical Model and Post-Tsunami Data from Banda Aceh, Indonesia

2009 ◽  
Vol 51 (3) ◽  
pp. 243-273 ◽  
Author(s):  
Shunichi Koshimura ◽  
Takayuki Oie ◽  
Hideaki Yanagisawa ◽  
Fumihiko Imamura
Keyword(s):  
Numerical Model ◽  
Fragility Functions ◽  
Damage Estimation ◽  
Tsunami Damage ◽  
Banda Aceh

Multiphase Transient Slugging Flow in Subsea Oil and Gas Production

2016 ◽  
Author(s):  
Zhenhua Zhang ◽  
Longbin Tao
Keyword(s):  
Data Analysis ◽  
Temperature Distribution ◽  
Numerical Model ◽  
Slug Flow ◽  
Field Data ◽  
Oil And Gas ◽  
Gas Production ◽  
Worst Case ◽  
Oil And Gas Production ◽  
Significant Difference

Slug flow in horizontal pipelines and riser systems in deep sea has been proved as one of the challenging flow assurance issues. Large and fluctuating gas/liquid rates can severely reduce production and, in the worst case, shut down, depressurization or damage topside equipment, such as separator, vessels and compressors. Previous studies are primarily based on experimental investigations of fluid properties with air/water as working media in considerably scaled down model pipes, and the results cannot be simply extrapolated to full scale due to the significant difference in Reynolds number and other fluid conditions. In this paper, the focus is on utilizing practical shape of pipe, working conditions and fluid data for simulation and data analysis. The study aims to investigate the transient multiphase slug flow in subsea oil and gas production based on the field data, using numerical model developed by simulator OLGA and data analysis. As the first step, cases with field data have been modelled using OLGA and validated by comparing with the results obtained using PIPESYS in steady state analysis. Then, a numerical model to predict slugging flow characteristics under transient state in pipeline and riser system was set up using multiphase flow simulator OLGA. One of the highlights of the present study is the new transient model developed by OLGA with an added capacity of newly developed thermal model programmed with MATLAB in order to represent the large variable temperature distribution of the riser in deep water condition. The slug characteristics in pipelines and temperature distribution of riser are analyzed under the different temperature gradients along the water depth. Finally, the depressurization during a shut-down and then restart procedure considering hydrate formation checking is simulated. Furthermore, slug length, pressure drop and liquid hold up in the riser are predicted under the realistic field development scenarios.

scholarly journals Predicting mangrove forest dynamics across a soil salinity gradient using an individual-based vegetation model linked with plant hydraulics

2021 ◽  
Author(s):  
Masaya Yoshikai ◽  
Takashi Nakamura ◽  
Rempei Suwa ◽  
Sahadev Sharma ◽  
Rene Rollon ◽  
...  
Keyword(s):  
Salt Stress ◽  
Soil Salinity ◽  
Mangrove Forest ◽  
Field Data ◽  
Salinity Gradient ◽  
Carbon Gain ◽  
Mangrove Forests ◽  
Bruguiera Gymnorrhiza ◽  
Rhizophora Stylosa ◽  
Plant Hydraulics

Abstract. In mangrove forests, soil salinity is one of the most significant environmental factors determining mangrove forest distribution and productivity as it limits plant water uptake and carbon gain. However, salinity control on mangrove productivity through plant hydraulics has not been investigated by existing mangrove models. Thus, we present a new individual-based model linked with plant hydraulics to incorporate physiological characterization of mangrove growth under salt stress. Plant hydraulics was associated with mangroves nutrient uptake and biomass allocation apart from water flux and carbon gain. The developed model was performed for two-coexisting species of Rhizophora stylosa and Bruguiera gymnorrhiza in a subtropical mangrove forest in Japan. The model predicted that the productivity of both species was affected by soil salinity through downregulation of stomatal conductance, while B. gymnorrhiza trees grow faster and suppress the growth of R. stylosa trees by shading that resulted in a B. gymnorrhiza-dominated forest under low soil salinity conditions (< 28 ‰). Alternatively, the increase in soil salinity significantly reduced the productivity of B. gymnorrhiza compared to R. stylosa, leading to an increase in biomass of R. stylosa despite the enhanced salt stress (> 30 ‰). These predicted patterns in forest structures across soil salinity gradient remarkably agreed with field data, highlighting the control of salinity on productivity and tree competition as factors that shape the mangrove forest structures. The model reproducibility of forest structures was also supported by the predicted self-thinning processes, which likewise agreed with field data. In addition, the mangroves morphological adjustment to increasing soil salinity – by decreasing transpiration and increasing hydraulic conductance – was reasonably predicted. Aside from the soil salinity, seasonal dynamics in atmospheric variables (solar radiation and temperature) was highlighted as factors influencing mangrove productivity in a subtropical region. The physiological principle-based improved model has the potential to be extended to other mangrove forests in various environmental settings, thus contributing to a better understanding of mangrove dynamics under future global climate change.

A practical technique for estimating service life of MSW leachate collection systems

2013 ◽  
Vol 50 (2) ◽  
pp. 165-178 ◽  
Author(s):  
R. Kerry Rowe ◽  
Yan Yu
Keyword(s):  
Numerical Model ◽  
Service Life ◽  
Field Data ◽  
Oxygen Demand ◽  
Collection System ◽  
Leachate Collection ◽  
Design Charts ◽  
Leachate Characteristics ◽  
Practical Model ◽  
Measured Field

The leachate characteristics and clogging of the leachate collection system at the Keele Valley Landfill is examined using the numerical model “BioClog”. The calculated effluent leachate concentrations (e.g., the chemical oxygen demand and calcium concentrations) and calculated calcium fraction in the clog material are in encouraging agreement with measured field data. A new practical model is developed and calibrated against the data from the sophisticated numerical model to estimate the service life of leachate collection systems in typical municipal solid waste (MSW) landfills. The procedures for using the new practical model are provided and illustrated by examples. Design charts are presented that may aid the design of leachate collection systems for typical MSW landfills.

Field Data and Satellite Imagery of Tsunami Effects in Banda Aceh

Science ◽  
2005 ◽  
Vol 308 (5728) ◽  
pp. 1596-1596 ◽  
Author(s):  
J. C. Borrero
Keyword(s):  
Satellite Imagery ◽  
Field Data ◽  
Banda Aceh

scholarly journals FLOW COMPUTATIONS NEARBY A STORM SURGE BARRIER UNDER CONSTRUCTION WITH TWO-DIMENSIONAL NUMERICAL MODELS

1986 ◽  
Vol 1 (20) ◽  
pp. 143
Author(s):  
H.E. Klatter ◽  
J.M.C. Dijkzeul ◽  
G. Hartsuiker ◽  
L. Bijlsma
Keyword(s):  
Numerical Model ◽  
Storm Surge ◽  
Field Data ◽  
Numerical Models ◽  
Flow Patterns ◽  
Scale Model ◽  
Energy Losses ◽  
Local Energy ◽  
Two Dimensional ◽  
Physical Scale

This paper discusses the application of two-dimensional tidal models to the hydraulic research for the storm surge barrier in the Eastern Scheldt in the Netherlands. At the site of the barrier local energy losses dominate the flow. Three methods are discussed for dealing with these energy losses in a numerical model based on the long wave equations. The construction of the storm surge barrier provided extensive field data for various phases of the construction of the barrier and these field data are used as a test case for the computation at methods developed. One method is preferred since it gives good agreement between computations and field data. The two-dimensional flow patterns, the discharge and the head-difference agree well,, The results of scale model tests were also available for comparison. This comparison demonstrated that depth-averaged velocities, computed by a two-dimensional numerical model, are as accurate as values obtained from a large physical scale model. Even compicated flow patterns with local energy losses and sharp velocity gradients compared well.

scholarly journals SWASH OSCILLATION AND RESULTING SEDIMENT MOVEMENT

1988 ◽  
Vol 1 (21) ◽  
pp. 87 ◽  
Author(s):  
Nobuhisha Kobayashi ◽  
Michael S. Strzelecki ◽  
Andojo Wurjanto
Keyword(s):  
Numerical Model ◽  
Field Data ◽  
Wave Setup ◽  
Sediment Movement

A numerical model for predicting the swash oscillation on a beach is described and compared with field data on wave setup and swash statistics on a moderately steep beach with a nearshore bar.

scholarly journals Crustal Fault Zones (CFZ) as Geothermal Power Systems: A Preliminary 3D THM Model Constrained by a Multidisciplinary Approach

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-24
Author(s):  
Hugo Duwiquet ◽  
Laurent Guillou-Frottier ◽  
Laurent Arbaret ◽  
Mathieu Bellanger ◽  
Théophile Guillon ◽  
...  
Keyword(s):  
High Temperature ◽  
Numerical Model ◽  
Power Systems ◽  
Fault Zone ◽  
Field Data ◽  
Large Scale ◽  
Numerical Models ◽  
Massif Central ◽  
Temperature Anomalies ◽  
Stress Direction

The Pontgibaud crustal fault zone (CFZ) in the French Massif Central provides an opportunity to evaluate the high-temperature geothermal potential of these naturally permeable zones. Previous 2D modeling of heat and mass transfer in a fault zone highlighted that a subvertical CFZ concentrates the highest temperature anomalies at shallow depths. By comparing the results of these large-scale 2D numerical models with field data, the depth of the 150°C isotherm was estimated to be at a depth of 2.5 km. However, these results did not consider 3D effects and interactions between fluids, deformation, and temperature. Here, field measurements are used to control the 3D geometry of the geological structures. New 2D (thin-section) and 3D (X-ray microtomography) observations point to a well-defined spatial propagation of fractures and voids, exhibiting the same fracture architecture at different scales (2.5 μm to 2 mm). Moreover, new measurements on porosity and permeability confirm that the highly fractured and altered samples are characterized by large permeability values, one of them reaching 10-12 m2. Based on a thermoporoelastic hypothesis, a preliminary 3D THM numerical model is presented. A first parametric study highlights the role of permeability, stress direction, and intensity on fluid flow. In particular, three different convective patterns have been identified (finger-like, blob-like, and double-like convective patterns). The results suggest that vertical deformation zones oriented at 30 and 70° with respect to the maximum horizontal stress direction would correspond to the potential target for high-temperature anomalies. Finally, a large-scale 3D numerical model of the Pontgibaud CFZ, based on THM coupling and the comparison with field data (temperature, heat flux, and electrical resistivity), allows us to explore the spatial geometry of the 150°C isotherm. Although simplified hypotheses have been used, 3D field data have been reproduced.

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