Source code for fences

'''This file is part of AeoLiS.

AeoLiS is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.

AeoLiS is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with AeoLiS.  If not, see <http://www.gnu.org/licenses/>.

AeoLiS  Copyright (C) 2015 Bas Hoonhout

bas.hoonhout@deltares.nl         b.m.hoonhout@tudelft.nl
Deltares                         Delft University of Technology
Unit of Hydraulic Engineering    Faculty of Civil Engineering and Geosciences
Boussinesqweg 1                  Stevinweg 1
2629 HVDelft                     2628CN Delft
The Netherlands                  The Netherlands

'''

import logging
import numpy as np
import scipy.special
import scipy.interpolate
from scipy import ndimage, misc
#import matplotlib
#import matplotlib.pyplot as plt
from builtins import range, int
import math
from collections import namedtuple
from copy import copy
from pprint import pprint as pp
import sys
import os
from aeolis.wind import velocity_stress

# package modules
from aeolis.utils import *

# initialize logger
logger = logging.getLogger(__name__)

def initialize(s,p):
    if p['process_fences']:
        s['fence_height'][:,:] = p['fence_file']
        s['fence_base'] = copy(s['zb'])  # initial fence base is the bed elevation
        s['fence_top'] = s['fence_base'] + s['fence_height']
        s['fence_height_init'] = s['fence_height']
        s['zf'] = s['fence_height']
    return s

def update_fences(s,p):
    s = update_fence_height(s, p)
    if p['ny'] > 0:
        s = fence_shear2d(s, p)
    else:
        s = fence_shear1d(s, p)

    s = velocity_stress(s,p)
    return s

def update_fence_height(s, p):
    s['fence_height'] = s['fence_top']-s['zb']
    ix = s['fence_height_init'] < 0.1
    s['fence_height'][ix] = 0
    ix = s['fence_top'] < 0.1
    s['fence_height'][ix] = 0
    ix = s['fence_height'] < 0.1
    s['fence_height'][ix] = 0

    #if exceeds 1.5 m then assume the fence has eroded out
    ix = s['fence_height'] > 1.5
    s['fence_height'][ix] = 0
    s['fence_height_init'][ix] = 0

    return s


def fence_shear2d(s, p):
    x = s['x']
    y = s['y']
    zf = s['fence_height']
    ustarx = s['ustars']
    ustary = s['ustarn']

    #dx = p['dx']/10
    #dy = p['dx']/10

    dx = np.maximum(p['dx']/2, 0.25)
    dy = dx


    udir = s['udir'][0, 0]
    if udir < 0:
        udir = udir + 360
    udir = udir - np.floor(udir / 360) * 360

    if udir == 0 or udir == 360 or udir == -360 or udir == -180 or udir == 180:
        udir += 0.00001

    igrid, cgrid, x0, y0 = initialize_computational_grid(x, y, zf, ustarx, ustary, dx, dy, buffer_width=100)
    igrid, cgrid = calc_fence_shear(igrid, cgrid, udir, x0, y0, p)

    s['ustars'] = igrid['ustarx']
    s['ustarn'] = igrid['ustary']
    s['ustar'] = np.sqrt(s['ustars']**2 + s['ustarn']**2)

    return s


def initialize_computational_grid(x, y, z, ustarx, ustary, dx, dy, buffer_width=100., buffer_relaxation=None):
    if buffer_relaxation is None:
        buffer_relaxation = buffer_width / 4.

    mult_all = np.ones(x.shape)

    igrid = dict(x=x,
                 y=y,
                 z=z,
                 ustarx=ustarx,
                 ustary=ustary,
                 mult_all=mult_all)

    cgrid = dict(dx=dx,
                 dy=dy)

    x0, y0, cgrid = set_computational_grid(igrid, cgrid, buffer_width)

    return igrid, cgrid, x0, y0


[docs] def set_computational_grid(igrid, cgrid, buffer_width): '''Define computational grid The computational grid is square with dimensions equal to the diagonal of the bounding box of the input grid, plus twice the buffer width. ''' gi = igrid gc = cgrid # grid center x0, y0 = np.mean(gi['x']), np.mean(gi['y']) # grid size D = np.sqrt((gi['x'].max() - gi['x'].min()) ** 2 + (gi['y'].max() - gi['y'].min()) ** 2) + 2 * buffer_width # determine equidistant, square grid xc, yc = get_exact_grid(x0 - D / 2., x0 + D / 2., y0 - D / 2., y0 + D / 2., gc['dx'], gc['dy']) gc['xi'] = xc gc['yi'] = yc return x0, y0, gc
[docs] def calc_fence_shear(igrid, cgrid, udir, x0, y0, p): '''Compute wind shear for given wind speed and direction Parameters ---------- u0 : float Free-flow wind speed udir : float Wind direction in degrees process_separattion : ''' gc = cgrid # computational grid gi = igrid # initial grid # Populate computational grid (rotate to wind direction + interpolate input topography) populate_computational_grid(igrid, cgrid, udir + 90., x0, y0) # Compute wind shear stresses on computational grid gc = compute_fenceshear(gi, gc, udir, p) ustarx_init = gc['ustarx'][0,0] gc['ustarx'] = gc['ustarx'] * gc['mult_all'] gc['ustary'] = np.zeros(gc['x'].shape) #ensure bad data doesnt make it through #ix = gc['mindist'] > 20 #gc['ustarx'][ix] = ustarx_init gc['ustarx'], gc['ustary'] = rotate(gc['ustarx'], gc['ustary'], udir + 90) # Rotate both (i&c) grids + results in opposite dir. gi['x'], gi['y'] = rotate(gi['x'], gi['y'], -(udir + 90.), origin=(x0, y0)) gc['x'], gc['y'] = rotate(gc['x'], gc['y'], -(udir + 90.), origin=(x0, y0)) gc['ustary'], gc['ustarx'] = rotate(gc['ustarx'], gc['ustary'], -(udir + 90)) # Interpolate wind shear results to real grid gi['ustarx'] = interpolate(gc['x'], gc['y'], gc['ustarx'], gi['x'], gi['y']) gi['ustary'] = interpolate(gc['x'], gc['y'], gc['ustary'], gi['x'], gi['y']) # Rotate real grid and wind shear results back to orignal orientation gc['x'], gc['y'] = rotate(gc['x'], gc['y'], udir + 90., origin=(x0, y0)) gi['x'], gi['y'] = rotate(gi['x'], gi['y'], +(udir + 90.), origin=(x0, y0)) gi['ustarx'], gi['ustary'] = rotate(gi['ustarx'], gi['ustary'], +(udir + 90)) #avoid any boundary effects #gi['ustarx'][1,:] = gi['ustarx'][2,:] #gi['ustarx'][:,1] = gi['ustarx'][:,2] #gi['ustarx'][-2,:] = gi['ustarx'][-3,:] #gi['ustarx'][:,-2] = gi['ustarx'][:,-3] #gi['ustary'][1,:] = gi['ustary'][1,:] #gi['ustary'][:,1] = gi['ustary'][:,1] #gi['ustary'][-2,:] = gi['ustary'][-2,:] #gi['ustary'][:,-2] = gi['ustary'][:,-2] gi['ustarx'][0,:] = gi['ustarx'][1,:] gi['ustarx'][:,0] = gi['ustarx'][:,1] gi['ustarx'][-1,:] = gi['ustarx'][-2,:] gi['ustarx'][:,-1] = gi['ustarx'][:,-2] gi['ustary'][0,:] = gi['ustary'][1,:] gi['ustary'][:,0] = gi['ustary'][:,1] gi['ustary'][-1,:] = gi['ustary'][-2,:] gi['ustary'][:,-1] = gi['ustary'][:,-2] return gi, gc
# Input functions for __call()
[docs] def populate_computational_grid(igrid, cgrid, alpha, x0, y0): '''Interpolate input topography to computational grid Adds and fills buffer zone around the initial grid and rotates the computational grid to current wind direction. The computational grid is filled by interpolating the input topography and initial wind induced shear stresses to it. Parameters ---------- alpha : float Rotation angle in degrees ''' gi = igrid gc = cgrid x = gi['x'] shp = x.shape try: ny = shp[2] except: ny = 0 # Add buffer zone around grid # buffer is based on version bart, sigmoid function is no longer required if ny <= 0: dxi = gi['x'][0, 0] dyi = gi['y'][0, 0] else: dxi = gi['x'][1, 1] - gi['x'][0, 0] dyi = gi['y'][1, 1] - gi['y'][0, 0] buf = 100 # amount of cells xi, yi = np.meshgrid( np.linspace(gi['x'][0, 0] - buf * dxi, gi['x'][-1, -1] + buf * dxi, gi['x'].shape[1] + 2 * buf), np.linspace(gi['y'][0, 0] - buf * dyi, gi['y'][-1, -1] + buf * dyi, gi['y'].shape[0] + 2 * buf)) zi = np.zeros((xi.shape)) zi[buf:-buf, buf:-buf] = gi['z'] # Filling buffer zone edges zi[buf:-buf, :buf] = np.repeat(zi[buf:-buf, buf + 1][:, np.newaxis], buf, axis=1) zi[buf:-buf, -buf:] = np.repeat(zi[buf:-buf, -buf - 1][:, np.newaxis], buf, axis=1) zi[:buf, buf:-buf] = np.repeat(zi[buf + 1, buf:-buf][np.newaxis], buf, axis=0) zi[-buf:, buf:-buf] = np.repeat(zi[-buf - 1, buf:-buf][np.newaxis], buf, axis=0) # Filling buffer zone corners zi[:buf, :buf] = zi[buf + 1, buf + 1] zi[-buf:, :buf] = zi[-buf - 1, buf + 1] zi[:buf, -buf:] = zi[buf + 1, -buf - 1] zi[-buf:, -buf:] = zi[-buf - 1, -buf - 1] # Rotate computational grid to the current wind direction xc, yc = rotate(gc['xi'], gc['yi'], alpha, origin=(x0, y0)) # Interpolate input topography to computational grid zfc = interpolate(gi['x'], gi['y'], gi['z'], xc, yc) ustarxc = interpolate(gi['x'], gi['y'], gi['ustarx'], xc, yc) ustaryc = interpolate(gi['x'], gi['y'], gi['ustary'], xc, yc) # Interpolate input wind - shear # tauxc = interpolate(gi['x'], gi['y'], gi['taux'], xc, yc) # tauyc = interpolate(gi['x'], gi['y'], gi['tauy'], xc, yc) gc['x'] = xc gc['y'] = yc gc['z'] = zfc # gc['taux'] = tauxc # gc['tauy'] = tauyc gc['zfc'] = zfc gc['ustarx'] = ustarxc gc['ustary'] = ustaryc return gc
[docs] def compute_fenceshear(igrid, cgrid, udir, p): '''Compute wind shear perturbation for given free-flow wind speed on computational grid Parameters ---------- u0 : float Free-flow wind speed nfilter : 2-tuple Wavenumber range used for logistic sigmoid filter. See :func:`filter_highfrequencies` ''' gc = cgrid zf = gc['z'] ny, nx = gc['z'].shape mult_all = np.ones(zf.shape) #mindist = np.ones(zf.shape) * 1000 for iy in range(ny): # intialize other grid parameters x = gc['x'][iy, :] zp = gc['z'][iy, :] red_all = np.zeros(x.shape) nx2 = x.size c1 = p['okin_c1_fence'] intercept = p['okin_initialred_fence'] for igrid in range(nx2): # only look at cells with a roughness element if zp[igrid] > 0: # print(zp[igrid]) # local parameters if udir >= 180 and udir <= 360: xrel = x - x[igrid] else: xrel = -(x - x[igrid]) red = np.zeros(x.shape) mult = np.ones(x.shape) h = zp[igrid] for igrid2 in range(nx2): if xrel[igrid2] >= 0 and xrel[igrid2] / h < 20: # apply okin model # apply okin model mult[igrid2] = intercept + (1 - intercept) * (1 - math.exp(-xrel[igrid2] * c1 / h)) #ifind = xrel > 0 #if np.size(ifind) > 0: # mindist[iy, igrid2] = np.minimum(np.min(xrel[ifind]), mindist[iy, igrid2]) red = 1 - mult # fix potential issues for summation ix = red < 0.00001 red[ix] = 0 ix = red > 1 red[ix] = 1 ix = xrel < 0 red[ix] = 0 # combine all reductions between plants red_all = red_all + red # cant have more than 100% reduction ix = red_all > 1 red_all[ix] = 1 # convert to a multiple mult_all[iy, :] = 1 - red_all #mult_all[iy, igrid2] = mult_all[iy, igrid2] - mult_temp #avoid any boundary effects mult_all[0,:] = 1 mult_all[:,0] = 1 mult_all[-1,:] = 1 mult_all[:,-1] = 1 cgrid['mult_all'] = mult_all #cgrid['mindist'] = mindist return cgrid
[docs] def get_exact_grid(xmin, xmax, ymin, ymax, dx, dy): '''Returns a grid with given gridsizes approximately within given bounding box''' x = np.arange(np.floor(xmin / dx) * dx, np.ceil(xmax / dx) * dx, dx) y = np.arange(np.floor(ymin / dy) * dy, np.ceil(ymax / dy) * dy, dy) x, y = np.meshgrid(x, y) return x, y
[docs] def rotate(x, y, alpha, origin=(0, 0)): '''Rotate a matrix over given angle around given origin''' xr = x - origin[0] yr = y - origin[1] a = alpha / 180. * np.pi R = np.asmatrix([[np.cos(a), -np.sin(a)], [np.sin(a), np.cos(a)]]) xy = np.concatenate((xr.reshape((-1, 1)), yr.reshape((-1, 1))), axis=1) * R return (np.asarray(xy[:, 0].reshape(x.shape) + origin[0]), np.asarray(xy[:, 1].reshape(y.shape) + origin[1]))
[docs] def interpolate(x, y, z, xi, yi): '''Interpolate one grid to an other''' xy = np.concatenate((y.reshape((-1, 1)), x.reshape((-1, 1))), axis=1) xyi = np.concatenate((yi.reshape((-1, 1)), xi.reshape((-1, 1))), axis=1) # version Bart inter = scipy.interpolate.RegularGridInterpolator((y[:, 0], x[0, :]), z, bounds_error=False, fill_value=0.) zi = inter(xyi).reshape(xi.shape) return zi
def fence_shear1d(s, p): ustar = s['ustar'].copy() ustars = s['ustars'].copy() ustarn = s['ustarn'].copy() ets = np.zeros(s['zb'].shape) etn = np.zeros(s['zb'].shape) ix = ustar != 0 ets[ix] = ustars[ix] / ustar[ix] etn[ix] = ustarn[ix] / ustar[ix] udir = s['udir'][0,0]+180 x = s['x'][0,:] zp = s['fence_height'][0,:] red = np.zeros(x.shape) red_all = np.zeros(x.shape) nx = x.size c1 = p['okin_c1_fence'] intercept = p['okin_initialred_fence'] if udir < 360: udir = udir + 360 if udir > 360: udir = udir - 360 #Calculate shear reduction by looking through all cells that have plants present and looking downwind of those features for igrid in range(nx): if zp[igrid] > 0: # only look at cells with a roughness element mult = np.ones(x.shape) h = zp[igrid] #vegetation height at the appropriate cell if udir >= 180 and udir <= 360: xrel = -(x - x[igrid]) else: xrel = x - x[igrid] for igrid2 in range(nx): if xrel[igrid2] >= 0 and xrel[igrid2]/h < 20: # apply okin model mult[igrid2] = intercept + (1 - intercept) * (1 - math.exp(-xrel[igrid2] * c1 / h)) red = 1 - mult # fix potential issues for summation ix = red < 0.00001 red[ix] = 0 ix = red > 1 red[ix] = 1 ix = xrel < 0 red[ix] = 0 # combine all reductions between plants red_all = red_all + red # cant have more than 100% reduction ix = red_all > 1 red_all[ix] = 1 # convert to a multiple mult_all = 1 - red_all ustarfence = s['ustar'][0,:] * mult_all ix = ustarfence < 0.01 ustarfence[ix] = 0.01 #some small number so transport code doesnt crash s['ustar'][0,:] = ustarfence s['ustars'][0,:] = s['ustar'][0,:] * ets[0,:] s['ustarn'][0,:] = s['ustar'][0,:] * etn[0,:] return s