Model setup XBeach 1D

Setup a 1D XBeach model with the Python toolbox.

# import default modules
import numpy as np
import matplotlib.pyplot as plt
from matplotlib import cm
import sys
import os

# method to import xbtools with try routine
try:
    import xbTools
except ImportError:
    print('**no xbTools installation found in environment, adding parent path of notebook to see if it works')
    sys.path.append(os.path.abspath(os.path.join('..', '..', 'xbeach-toolbox')))

**no xbTools installation found in environment, adding parent path of notebook to see if it works

Import the toolbox.

## import xbeach tools
#sys.path.append(os.path.abspath(os.path.join('..' )))

from xbTools.grid.creation import xgrid, ygrid
from xbTools.grid.extension import seaward_extend
from xbTools.xbeachtools import XBeachModelSetup
from xbTools.general.wave_functions import offshore_depth

Data

Load and plot the bathymetry data

## load data
bathy = np.loadtxt('..//examples//data//input//bathy.dep')
bathy = bathy[0,:]

## set bathy grid
nx = 124
ny = 72
dx = 5
dy = 20

x = np.linspace(0,(nx-1)*dx,nx)

## plot
plt.figure()
plt.plot(x,bathy)
plt.xlabel('x [m]')
plt.ylabel('z [m]')
plt.grid('on')
plt.title('bathy')

Text(0.5, 1.0, 'bathy')

Create x-grid

Create spatially varying x-grid resolution. In this example a minimum grid resolution of 2 m is applied.

Note that the following settings can be specified:

xgrid(x,z,           ppwl=20,           dxmin=5,           dxmax=np.inf,           vardx=1,           wl = 0,           eps = 0.01,           Tm = 8,           xdry=None,           zdry=None,           dxdry = None,           depthfac = 2,           maxfac = 1.15,           nonh = False)

xgr,zgr = xgrid(x, bathy,dxmin=2)


plt.figure()
plt.plot(x,bathy,'-o')
plt.plot(xgr,zgr,'.-')
plt.legend(['Bathy','xgr'])
plt.xlabel('x [m]')
plt.ylabel('z [m]')
plt.grid('on')

Interpolate

Interpolate data to xb grid.

zgr = np.interp(xgr, x, bathy)

plt.figure()
plt.plot(x,bathy,'-o')
plt.plot(xgr,zgr,'.-')
plt.xlabel('x [m]')
plt.ylabel('x [m]')
plt.title('xb bathy')
plt.grid('on')

Seaward extend

Extend the grid to the required offshore depth. In this case 20 m with a artifial slope of 1/20.

If desired the function offshore_depth can also be used to determine the required offshore water depth.

#d_start, slope, Hm0_shoal = offshore_depth(Hm0=9, Tp=15, depth_offshore_profile=15, depth_boundary_conditions=20)

xgr, ygr, zgr = seaward_extend(xgr,[0],zgr,slope=1/20,depth=-20)



plt.figure()
plt.plot(xgr.T,zgr[:,:].T)
plt.xlabel('x [m]')
plt.ylabel('z [m]')

Text(0, 0.5, 'z [m]')

Create model setup

Create the model setup class

xb_setup = XBeachModelSetup('Test som 2')

print(xb_setup)

Test som 2

Add the grid, wave boundary conditions and parameter to the model.

Note that the following grid settings can be specified:

set_grid(self,xgr,ygr,zgr, posdwn=1, xori=0, yori=0,alfa=0, thetamin=-90, thetamax = 90, dtheta=10, dtheta_s=10)

Two different boundary conditions can be specified: jonstable or parametric.

xb_setup.set_grid(xgr,None,zgr)

xb_setup.set_waves('parametric',{'Hm0':2, 'Tp':5, 'mainang':270, 'gammajsp':3.3, 's' : 10000, 'fnyq':1})
#xb_setup.set_waves('jonstable',{'Hm0':[1.5, 2, 1.5],'Tp':[4, 5, 4],'gammajsp':[3.3, 3.3, 3.3], 's' : [20,20,20], 'mainang':[270,280, 290],'duration':[3600, 3600, 3600],'dtbc':[1,1,1]})

xb_setup.set_params({'Wavemodel':'surfbeat',
                     'morphology':0,
                     'befriccoef':0.01,
                     'tstop':3600,
                     'zs0':0,
                     'nglobalvar':['zb','zs','H'],
                     'npointvar':['zs','zb'],
                     'nmeanvar':['zb'],
                     'npoints':['1 0', '6 0', '10 0', '12 0']})

Write the model setup

sim_path = os.path.join('xb-1D')
if not os.path.exists(sim_path):
    os.mkdir(sim_path)
xb_setup.write_model(sim_path)

Not possible to plot wave boundary