scholarly journals REALISTIC ECONOMIC BENEFITS FROM BEACH NOURISHMENT

1988 ◽  
Vol 1 (21) ◽  
pp. 116 ◽  
Author(s):  
Robert G. Dean
Keyword(s):  
Central Element ◽  
Beach Nourishment ◽  
Economic Benefits ◽  
Sand Transport ◽  
Storm Damage ◽  
Large Wave ◽  
Project Area ◽  
Damage Reduction ◽  
Wave Heights ◽  
Recreational Benefits

A method is presented and Illustrated with examples to establish appropriate storm damage reduction and recreational benefits from beach nourishment projects. Unlike previous methods, benefits to project adjacent areas are recognized due to sand transport out of the project area and deposition on adjacent beaches. Assuming homogeniety along the shoreline, the character of storm damage reduction and recreational benefit relationships are such that sand transported from a project area and deposited on adjacent beaches always results in an increase rather than a reduction in benefits. A central element in calculating storm damage reduction benefits is the establishment of a proportional damage curve for upland structures as a function of beach width and storm return period. To illustrate the method, limiting cases are presented in which (A) all sediment remains within the area placed, and (B) all sediment spreads out immediately over a long segment of shoreline. Using Monte Carlo simulation to represent the random character of the storms, the method is applied to 15 realistic cases with varying project lengths, representative wave heights, added beach widths and interest rates. The present worth storm damage reduction and recreational benefits are calculated to demonstrate the effects of the various parameters. It is found that for short project lengths and relatively large wave heights, the benefits from project adjacent areas exceed those in the project area where the sand is placed. Although no littoral control structures, such as jetties are included in the present application, the method could be extended readily to include their effects.

scholarly journals Focusing of long waves with finite crest over constant depth

2013 ◽  
Vol 469 (2153) ◽  
pp. 20130015 ◽  
Author(s):  
Utku Kânoğlu ◽  
Vasily V. Titov ◽  
Baran Aydın ◽  
Christopher Moore ◽  
Themistoklis S. Stefanakis ◽  
...  
Keyword(s):  
Source Region ◽  
Wave Theory ◽  
Long Waves ◽  
Constant Depth ◽  
Large Wave ◽  
Weakly Nonlinear ◽  
Scaling Relationships ◽  
2011 Japan Tsunami ◽  
Wave Heights ◽  
Run Up

Tsunamis are long waves that evolve substantially, through spatial and temporal spreading from their source region. Here, we introduce a new analytical solution to study the propagation of a finite strip source over constant depth using linear shallow-water wave theory. This solution is not only exact, but also general and allows the use of realistic initial waveforms such as N -waves. We show the existence of focusing points for N -wave-type initial displacements, i.e. points where unexpectedly large wave heights may be observed. We explain the effect of focusing from a strip source analytically, and explore it numerically. We observe focusing points using linear non-dispersive and linear dispersive theories, analytically; and nonlinear non-dispersive and weakly nonlinear weakly dispersive theories, numerically. We discuss geophysical implications of our solutions using the 17 July 1998 Papua New Guinea and the 17 July 2006 Java tsunamis as examples. Our results may also help to explain high run-up values observed during the 11 March 2011 Japan tsunami, which are otherwise not consistent with existing scaling relationships. We conclude that N -waves generated by tectonic displacements feature focusing points, which may significantly amplify run-up beyond what is often assumed from widely used scaling relationships.

Danger! Glyphosate may Expose Weaknesses in Institutional Systems: EU Legislation and Comitology in the Face of a Controversial Reauthorisation

2020 ◽  
Vol 11 (3) ◽  
pp. 436-449
Author(s):  
Ton VAN DEN BRINK
Keyword(s):  
Plant Protection ◽  
Current System ◽  
Central Element ◽  
Essential Element ◽  
Plant Protection Products ◽  
Economic Benefits ◽  
Essential Elements ◽  
Member States ◽  
The Face ◽  
Legislative Choice

The 2017 glyphosate reauthorisation process has exposed key weaknesses of the EU’s institutional system. First, the role of Germany as Member State rapporteur and the subsequent decision to appoint a group of Member States to form the Assessment Group on Glyphosate (AGG) suggest that the nature of scientific assessments become blurred. These assessments are apparently not just purely objective, science-based and procedural elements of the authorization procedure, but require support from a significant number of Member States as well. Second, the arduous comitology trajectory in the glyphosate reauthorisation process has caused the Commission to initiate questionable changes to comitology. These changes would corrupt the coherence of the EU’s legislative system in general and the constitutional distinction between delegated and implementing acts in particular. Moreover, they would overlook the more obvious solution of relying more on discretion on the part of the Commission. Lastly, the glyphosate reauthorisation has questioned the dichotomy between legislation and executive rule-making, an equally central element of the EU’s constitutional order. This dichotomy is based on a distinction between essential elements that belong to the legislative domain and non-essential element which are more technical in nature. It has been claimed that weighing the economic benefits of pesticides against the health and environmental costs associated with their use is in essence a legislative choice. This claim highlights not so much the practical problem of how to draw the line between political and technical decision-making, but rather denies the very meaning of the dichotomy altogether. Yet, the current system on the placing on the market of plant protection products – based on the legislation providing the general framework and the executive applying this in concrete cases – is certainly not devoid of coherence and logic.

scholarly journals EXPERIMENTS ON BEACH PROFILE CHANGE WITH A LARGE WAVE FLUME

1982 ◽  
Vol 1 (18) ◽  
pp. 85 ◽  
Author(s):  
Ryoichi Kajima ◽  
Takao Shimizu ◽  
Kohki Maruyama ◽  
Shozo Saito
Keyword(s):  
Simple Model ◽  
Transport Rate ◽  
Sand Transport ◽  
Two Dimensional ◽  
Beach Profile ◽  
Large Wave ◽  
Wave Flume ◽  
Grain Sizes ◽  
Profile Changes ◽  
Profile Change

Two-dimensional beach profile changes were investigated with a newly constructed prototype-scale wave flume. The flume is 205 m long, 3.4 m wide and 6 m deep. Sand of two grain sizes was used in the experiments. Analysis of the results was made through use of the parameter C, introduced by Sunamura and Horikawa (1974) to classify beaches as either erosional and accretionary. Beach profile changes obtained in the flume were similar to those in the prototype (field). Net sand transport rate distributions were classified into five types, two of which do not seem to have been observed in laboratory (smallscale) experiments. A simple model describing the five types was developed for evaluating two-dimensional beach profile changes.

scholarly journals WAVE OVERTOPPIMG EQUATION

1976 ◽  
Vol 1 (15) ◽  
pp. 156 ◽  
Author(s):  
J. Richard Weggel
Keyword(s):  
Scale Effects ◽  
Beach Erosion ◽  
Scale Model ◽  
Lake Okeechobee ◽  
Wave Runup ◽  
Large Wave ◽  
Engineering Research ◽  
Test Conditions ◽  
Model Wave ◽  
Wave Heights

In the early 1950's the Corps of Engineers' Jacksonville District initiated a series of laboratory tests to investigate the overtopping of proposed levee sections for Lake Okeechobee, Florida. For economic reasons, the alternative to build levees with crest elevations that were at times below the limit of wave runup was investigated and the quantities of water carried over the structures for various freeboard allowances, structure slopes and wave conditions determined. The initial tests were conducted at the Waterways Experiment Station (WES) in Vieksburg, Mississippi for the Jacksonville District at what was taken to be a 1 to 30 model scale. Model wave heights varied from 1+.05 cm to 12.2 cm (0.133 to 0.^0 ft). In order to expand the range of test conditions investigated, the Beach Erosion Board, currently the Coastal Engineering Research Center (CERC), commissioned an expanded series of tests that considered the overtopping of riprap faced, curved and stepped seawalls as well as the overtopping of "smooth" slopes. These tests, also conducted at WES, were considered to be at a 1 to 17 scale with model wave heights ranging from 5-36 cm to 21.5 cm (0.176 to O.706 ft). A number of tests were subsequently conducted in CERC's large wave tank to determine the influence scale effects might have on overtopping. These tests are referred to as 1 to 2 1/2 scale tests. The model wave heights investigated ranged from U8.8 cm to 11*0.2 cm. (1.60 to h.6o ft).

Numerical Simulation of Nonlinear Wave Propagation and Breaking Over Constant-Slope Bottom

2006 ◽  
Author(s):  
Aggelos S. Dimakopoulos ◽  
Athanassios A. Dimas
Keyword(s):  
Numerical Simulation ◽  
Free Surface ◽  
Free Surface Flow ◽  
Surface Flow ◽  
Surface Boundary ◽  
Nonlinear Wave Propagation ◽  
Large Wave ◽  
Slope Bottom ◽  
Wave Heights ◽  
Constant Slope

The numerical simulation of the two-dimensional free-surface flow resulting from the propagation of nonlinear gravity waves over constant-slope bottom is presented. The simulation is based on the numerical solution of the Euler equations subject to the fully nonlinear free-surface boundary conditions and the appropriate bottom, inflow and outflow conditions using a hybrid finite-differences and spectral-method scheme. Wave breaking is accounted for by a surface roller model. The formulation includes a boundary-fitted transformation and is suitable for future extension to incorporate large-eddy and large-wave simulation terms. Results are presented for the simulation of the free-surface flow over two different bottom topographies, with constant slope values of 1:10 and 1:50, and three different inflow wave heights. Over the bottom slope, waves of small wave heights are modified according to linear theory. For nonlinear waves, wavelengths are becoming shorter, the free surface elevation deviates from its initial sinusoidal shape and wave heights increase with decreasing depth. Breaking is observed for the cases with the larger initial wave height and the smaller outflow depth.

Research on Readjustments of Land Property Rights in Comprehensive Land Management

2014 ◽  
Vol 484-485 ◽  
pp. 488-492
Author(s):  
Yi Liu ◽  
Xin Ju Li
Keyword(s):  
Property Rights ◽  
Land Management ◽  
Economic Benefits ◽  
Analysis Method ◽  
Ecological Benefits ◽  
Project Area ◽  
The Social ◽  
The Right ◽  
Rural Construction ◽  
Land Property Rights

Research purpose: The paper studies readjustments of land property rights which practice in the project area of Fan Zhen comprehensive land management in Taian City. According to the study make reasonable suggestions, for the similar areas of readjustments of land property rights provide experience. Research Methods: Investigating method and contrastive analysis method. Results: The right of the project area to an adjustment measures properly, and has achieved good economic benefits, social benefits and ecological benefits. Research Conclusions: Developing the new rural construction the problem from the social, economic and environmental field, effectively protect the fundamental interests of farmers to get sustainable development.

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