How to add coastal structures into model

Discussion of how to use ROMS on different regional and basin scale applications.

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How to add coastal structures into model

#1 Post by liangliang »

Hello all:
In my study region,there are some coastal structures .For example ,breakwaters,jetties ,and so on.
Usually,the size of structures is too small for grid size to generate in grid.Whether can i add coastal structures into model in other method?

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Re: How to add coastal structures into model

#2 Post by kate »

Right now there is no way to include anything that's too small to mask out. Maybe there could be a way to specify the flow through a wall between adjacent grid cells and then set it to zero, but you'd have to have the grid aligned with them just so and you wouldn't really be resolving them anyway.

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Re: How to add coastal structures into model

#3 Post by xiaozhu557 »

when i creat the grid file by EASYGRID, it report a error!
In the easygrid.m files, I set
% Geographical and Grid parameters --------
lat = 0.86; % Latitude (degrees) of the bottom-left corner of the grid.
lon = 99; % Longitude (degrees) of the bottom-left corner of the grid.

X = 3120000; % Width of domain (meters) 26.33
Y = 2800000; % Length of domain (meters)
rotangle = 0; % Angle (degrees) to rotate the grid conterclock-wise
resol = 11000; % Cell width and height (i.e. Resolution)in meters. Grid cells are forced to be (almost) square.
N = 10; % Number of vertical levels

And the *_bathy.mat file is created by myself, and the area is 0.8~26.5N 98.5~131 E,resolution is 2 minutes.

??? Error using ==> qhullmx
qhull precision warning:
The initial hull is narrow (cosine of min. angle is 1.0000000000000002).
A coplanar point may lead to a wide facet. Options 'QbB' (scale to unit box)
or 'Qbb' (scale last coordinate) may remove this warning. Use 'Pp' to skip
this warning. See 'Limitations' in

qhull precision error: initial simplex is not convex. Distance=1.2e-014

While executing: | qhull d Qt Qbb Qc

Options selected for Qhull 2003.1 2003/12/30:
delaunay Qtriangulate Qbbound-last Qcoplanar-keep _pre-merge
_zero-centrum Pgood Qinterior-keep _max-width 35 Error-roundoff 1.6e-013
_one-merge 1.2e-012 Visible-distance 3.3e-013 U-coplanar-distance 3.3e-013
Width-outside 6.6e-013 _wide-facet 2e-012 _narrow-hull -2.2e-016

precision problems (corrected unless 'Q0' or an error)

flipped facets

The input to qhull appears to be less than 3 dimensional, or a
computation has overflowed.

Qhull could not construct a clearly convex simplex from points:

The center point is coplanar with a facet, or a vertex is coplanar
with a neighboring facet. The maximum round off error for
computing distances is 1.6e-013. The center point, facets and distances
to the center point are as follows:

distance= -8.9e-015

distance= -1.8e-015

distance= -1.8e-015

distance= -3.6e-015

These points either have a maximum or minimum x-coordinate, or
they maximize the determinant for k coordinates. Trial points
are first selected from points that maximize a coordinate.

The min and max coordinates for each dimension are:

0: 99 130.5 difference= 31.5

1: 0.8333 36.17 difference= 35.33

2: 0 35.33 difference= 35.33

If the input should be full dimensional, you have several options that
may determine an initial simplex:
- use 'QJ' to joggle the input and make it full dimensional
- use 'QbB' to scale the points to the unit cube
- use 'QR0' to randomly rotate the input for different maximum points
- use 'Qs' to search all points for the initial simplex
- use 'En' to specify a maximum roundoff error less than 1.6e-013.
- trace execution with 'T3' to see the determinant for each point.

If the input is lower dimensional:
- use 'QJ' to joggle the input and make it full dimensional
- use 'Qbk:0Bk:0' to delete coordinate k from the input. You should
pick the coordinate with the least range. The hull will have the
correct topology.
- determine the flat containing the points, rotate the points
into a coordinate plane, and delete the other coordinates.
- add one or more points to make the input full dimensional.

This is a Delaunay triangulation and the input is co-circular or co-spherical:
- use 'Qz' to add a point "at infinity" (i.e., above the paraboloid)
- or use 'QJ' to joggle the input and avoid co-circular data

Error in ==> delaunayn at 117
t = qhullmx(x', 'd ', opt);

Error in ==> griddata>linear at 151
tri = delaunayn([x y]);

Error in ==> griddata at 120
zi = linear(x,y,z,xi,yi,opt);

Error in ==> south_sea_easygrid at 281
h = griddata(xbathy,ybathy,zbathy,lon_rho,lat_rho,'linear');

But when I run easygrid.m and use the depth from ETOPO5 by

%This reads in worldwide bathymetry at 60 second (1 minute) resolution,
%30seconds max
xbathy = xbathy(:); %columnize
ybathy = ybathy(:); %columnize
zbathy = -zbathy(:); %columnize, and make depth positive
% outname=strcat(name,'_bathy.mat','interpreter','none')

it is OK. So I don't know the reasons when I use my depth mat file, it is created by
save south_sea_bathy xbathy ybathy zbathy

Who can tell me the reasons for that? Thank you very much!!

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