def _sindex_drain_points(parm_dict):
# for each drain point in the drain points shape file find the cell value in the combined stability index grid file
# and use that value to populate the corresponding row in the drainpoints table
driver = ogr.GetDriverByName(utils.GDALFileDriver.ShapeFile())
dataSource = driver.Open(parm_dict[ParameterNames.drain_points_file], 1)
layer = dataSource.GetLayer()
layerDefn = layer.GetLayerDefn()
fld_index_graipdid = layerDefn.GetFieldIndex('GRAIPDID')
si_grid = gdal.Open(parm_dict[ParameterNames.csi_grid_file])
si_band = si_grid.GetRasterBand(1)
road_impact = False
if parm_dict[ParameterNames.demang_file]:
road_impact = True
field_to_create = 'SIR' if road_impact else 'SI'
try:
#delete field if it exists in drainpoints shapefile
fld_index_dp = layerDefn.GetFieldIndex(field_to_create)
if fld_index_dp > 0:
layer.DeleteField(fld_index_dp)
# add a new field (column) to the attribute table of drainpoints shapefile
layer.CreateField(ogr.FieldDefn(field_to_create, ogr.OFTReal))
fld_index_dp = layerDefn.GetFieldIndex(field_to_create)
except:
pass
try:
conn = pyodbc.connect(utils. MS_ACCESS_CONNECTION % parm_dict[ParameterNames.mdb])
cursor = conn.cursor()
for feature in layer:
geom = feature.GetGeometryRef()
total_points = geom.GetPointCount()
if total_points > 0:
# lookup grid cell at drain point
row, col = utils.get_coordinate_to_grid_row_col(geom.GetX(0), geom.GetY(0), si_grid)
si_cell_data = si_band.ReadAsArray(xoff=col, yoff=row, win_xsize=1, win_ysize=1)
graipdid = feature.GetFieldAsInteger(fld_index_graipdid)
dp_row = cursor.execute("SELECT * FROM DrainPoints WHERE GRAIPDID=%d" % graipdid).fetchone()
if dp_row:
if si_cell_data[0][0] == si_band.GetNoDataValue():
if road_impact:
dp_row.SIR = -9999
else:
dp_row.SI = -9999
else:
if road_impact:
dp_row.SIR = float(si_cell_data[0][0])
else:
dp_row.SI = float(si_cell_data[0][0])
if road_impact:
update_sql = "UPDATE DrainPoints SET SIR=? WHERE GRAIPDID=?"
data = (dp_row.SIR, dp_row.GRAIPDID)
else:
update_sql = "UPDATE DrainPoints SET SI=? WHERE GRAIPDID=?"
data = (dp_row.SI, dp_row.GRAIPDID)
cursor.execute(update_sql, data)
# write si data to drainpoints shapefile
feature.SetField(fld_index_dp, data[0])
# rewrite the feature to the layer - this will in fact save the data to the file
layer.SetFeature(feature)
geom = None
conn.commit()
except:
raise
finally:
# cleanup
if conn:
conn.close()
if dataSource:
dataSource.Destroy()
def compute_mass_potential(graip_db, dp_shp, slpd, alpha, si=None, sic=None, dist=None):
conn = pyodbc.connect(utils.MS_ACCESS_CONNECTION % graip_db)
cursor = conn.cursor()
slpd_gdal = gdal.Open(slpd)
slpd_gdal_band = slpd_gdal.GetRasterBand(1)
if si:
si_gdal = gdal.Open(si)
si_gdal_band = si_gdal.GetRasterBand(1)
if sic:
sic_gdal = gdal.Open(sic)
sic_gdal_band = sic_gdal.GetRasterBand(1)
if dist:
dist_gdal = gdal.Open(dist)
dist_gdal_band = dist_gdal.GetRasterBand(1)
# open the drainpoints shapefile
driver = ogr.GetDriverByName(utils.GDALFileDriver.ShapeFile())
dataSource = driver.Open(dp_shp, 1)
layer = dataSource.GetLayer()
try:
# for each drain point in shape file
for dp in layer:
geom = dp.GetGeometryRef()
# find grid row and col corresponding to drain point
row, col = utils.get_coordinate_to_grid_row_col(geom.GetX(0), geom.GetY(0), slpd_gdal)
geom = None
# get the id of the drain point from shape file
graipdid = dp.GetField('GRAIPDID')
# get current grid cell data
current_cell_slope_data = slpd_gdal_band.ReadAsArray(xoff=col, yoff=row, win_xsize=1, win_ysize=1)
if si:
current_cell_si_data = si_gdal_band.ReadAsArray(xoff=col, yoff=row, win_xsize=1, win_ysize=1)
if sic:
current_cell_sic_data = sic_gdal_band.ReadAsArray(xoff=col, yoff=row, win_xsize=1, win_ysize=1)
if dist:
current_cell_dist_data = dist_gdal_band.ReadAsArray(xoff=col, yoff=row, win_xsize=1, win_ysize=1)
dp_row = cursor.execute("SELECT * FROM DrainPoints WHERE GRAIPDID=%d" % graipdid).fetchone()
if dp_row:
if current_cell_slope_data[0][0] != slpd_gdal_band.GetNoDataValue():
dp_row.Slope = float(current_cell_slope_data[0][0])
dp_row.ESI = dp_row.ELength * math.pow(dp_row.Slope, alpha)
else:
dp_row.Slope = utils.NO_DATA_VALUE
dp_row.ESI = utils.NO_DATA_VALUE
update_sql = "UPDATE DrainPoints SET Slope=?, ESI=? WHERE GRAIPDID=?"
data = (dp_row.Slope, dp_row.ESI, dp_row.GRAIPDID)
cursor.execute(update_sql, data)
if si:
if current_cell_si_data[0][0] != si_gdal_band.GetNoDataValue():
dp_row.SI = float(current_cell_si_data[0][0])
else:
dp_row.SI = utils.NO_DATA_VALUE
update_sql = "UPDATE DrainPoints SET SI=? WHERE GRAIPDID=?"
data = (dp_row.SI, dp_row.GRAIPDID)
cursor.execute(update_sql, data)
if sic:
if current_cell_sic_data[0][0] != sic_gdal_band.GetNoDataValue():
dp_row.SIR = float(current_cell_sic_data[0][0])
else:
dp_row.SIR = utils.NO_DATA_VALUE
update_sql = "UPDATE DrainPoints SET SIR=? WHERE GRAIPDID=?"
data = (dp_row.SIR, dp_row.GRAIPDID)
cursor.execute(update_sql, data)
if dist:
if current_cell_dist_data[0][0] != dist_gdal_band.GetNoDataValue():
dp_row.DistToStream = float(current_cell_dist_data[0][0])
else:
dp_row.DistToStream = utils.NO_DATA_VALUE
update_sql = "UPDATE DrainPoints SET DistToStream=? WHERE GRAIPDID=?"
data = (dp_row.DistToStream, dp_row.GRAIPDID)
cursor.execute(update_sql, data)
conn.commit()
except:
raise
finally:
# cleanup
if conn:
conn.close()
if dataSource:
dataSource.Destroy()
def _create_weight_grids_from_points(weight_min_raster_file, weight_max_raster_file, params_dict):
# Reference: c++ function: createweightgridfrompoints
"""
Creates the temporary weight grids (min and max) to be used with TauDEM areadinf function
:param weight_min_raster_file: temporary weight grid file to which minimum weight data needs to be written
:param weight_max_raster_file: temporary weight grid file to which maximum weight data needs to be written
:param params_dict: a dictionary containing user parameter inputs for stability index computation
:return: None
"""
driver = ogr.GetDriverByName(utils.GDALFileDriver.ShapeFile())
data_source = driver.Open(params_dict[ParameterNames.drain_points_file], 1)
layer = data_source.GetLayer()
layer_defn = layer.GetLayerDefn()
try:
layer_defn.GetFieldIndex('GRAIPDID')
except:
data_source.Destroy()
raise utils.ValidationException("Invalid drain points shape file. Attribute 'GRAIPDID' is missing in "
"this file.")
try:
conn = pyodbc.connect(utils.MS_ACCESS_CONNECTION % params_dict[ParameterNames.mdb])
cursor = conn.cursor()
dp_rows = cursor.execute("SELECT * FROM DrainPoints ORDER BY GRAIPDID ASC").fetchall()
dp_type_rows = cursor.execute("SELECT * FROM DrainTypeDefinitions").fetchall()
accum_rmax = {}
accum_rmin = {}
for row in dp_rows:
accum_area = 0
matching_dp_type_row = [dpt_row for dpt_row in dp_type_rows if dpt_row.DrainTypeID == row.DrainTypeID][0]
if matching_dp_type_row.CCSI:
accum_area = row.ELength * float(params_dict[ParameterNames.road_width])
accum_rmin[row.GRAIPDID] = accum_area * float(params_dict[ParameterNames.min_additional_runoff])
accum_rmax[row.GRAIPDID] = accum_area * float(params_dict[ParameterNames.max_additional_runoff])
# open the output temp weight grid files to write data to it
weight_min_grid_file = gdal.Open(weight_min_raster_file, GA_Update)
weight_max_grid_file = gdal.Open(weight_max_raster_file, GA_Update)
# for each drain point in shape file
for dp in layer:
geom = dp.GetGeometryRef()
# find weight grid row and col corresponding to drain point
row, col = utils.get_coordinate_to_grid_row_col(geom.GetX(0), geom.GetY(0), weight_min_grid_file)
geom = None
# get the id of the drain point from shape file
graipdid = dp.GetField('GRAIPDID')
def _write_weight_to_grid(grid_file, weight_values):
# create a 2D array to store weight data
weight_array = np.zeros((1, 1), dtype=np.float32)
grid_file_band = grid_file.GetRasterBand(1)
# get current grid cell data
current_cell_data = grid_file_band.ReadAsArray(xoff=col, yoff=row, win_xsize=1, win_ysize=1)
if current_cell_data[0][0] != utils.NO_DATA_VALUE:
weight_array[0][0] = weight_values[graipdid]
# here we are writing to a specific cell of the grid
grid_file_band.WriteArray(weight_array, xoff=col, yoff=row)
_write_weight_to_grid(weight_min_grid_file, accum_rmin)
_write_weight_to_grid(weight_max_grid_file, accum_rmax)
grid_file_band = weight_min_grid_file.GetRasterBand(1)
grid_file_band.FlushCache()
grid_file_band = weight_max_grid_file.GetRasterBand(1)
grid_file_band.FlushCache()
except:
raise
finally:
if data_source:
data_source.Destroy()
if conn:
conn.close()
weight_min_grid_file = None
weight_max_grid_file = None
def compute_length_elevation_interpolation(rd_shapefile, input_dem):
"""
Calculates road segment length and elevation and writes to roadlines shapefile
:param rd_shapefile: Path to roadlines shapefile
:param input_dem: Path to dem file
:return: None
"""
# DEBUG:
print("Computing length/elevation interpolation...")
driver = ogr.GetDriverByName(utils.GDALFileDriver.ShapeFile())
dataSource = driver.Open(rd_shapefile, 1)
layer = dataSource.GetLayer()
layerDefn = layer.GetLayerDefn()
dem = gdal.Open(input_dem)
dem_nx = dem.RasterXSize
dem_ny = dem.RasterYSize
gt = dem.GetGeoTransform()
dem_band = dem.GetRasterBand(1)
# Compute mid-point grid spacings
# ref: http://gis.stackexchange.com/questions/7611/bilinear-interpolation-of-point-data-on-a-raster-in-python
# gt[0] dem originX
# gt[3] dem originY
# gt[1] dem cell width (in pixel)
# gt[5] dem cell height (in pixel)
ax = array([gt[0] + ix * gt[1] + gt[1] / 2.0 for ix in range(dem_nx)])
ay = array([gt[3] + iy * gt[5] + gt[5] / 2.0 for iy in range(dem_ny)])
try:
# delete field "Length" if it exists
fld_index = layerDefn.GetFieldIndex('Length')
if fld_index > 0:
layer.DeleteField(fld_index)
# delete "Range" if it exists
fld_index = layerDefn.GetFieldIndex('Range')
if fld_index > 0:
layer.DeleteField(fld_index)
except:
pass
# add a new field (column) 'Length' to the attribute table
layer.CreateField(ogr.FieldDefn('Length', ogr.OFTReal))
fld_index_length = layerDefn.GetFieldIndex('Length')
# add a new field (column) 'Range' to the attribute table
layer.CreateField(ogr.FieldDefn('Range', ogr.OFTReal))
fld_index_range = layerDefn.GetFieldIndex('Range')
for feature in layer:
try:
geom = feature.GetGeometryRef()
if geom:
total_points = geom.GetPointCount()
# write length value to shapefile
# feature.SetField(fld_index_length, geom.Length())
rd_length = geom.Length()
if total_points > 0:
# calculate range from the elevation of 2 end points of the road segment
# using interpolation
# first find the row, col of the dem corresponding to
# the fist point of the road segment
row, col = utils.get_coordinate_to_grid_row_col(
geom.GetX(0), geom.GetY(0), dem)
# get the dem cells corresponding to row, col needed to generate the interpolation function
dem_array = dem_band.ReadAsArray(xoff=col,
yoff=row,
win_xsize=2,
win_ysize=2)
# define the interpolation function
bilinterp = interpolate.interp2d(ax[col:col + 2],
ay[row:row + 2],
dem_array,
kind='linear')
# find the elevation of the 1st point using the interpolation function
elevation_1 = bilinterp(geom.GetX(0), geom.GetY(0))[0]
# find the row, col of the dem corresponding to
# the 2nd point of the road segment
row, col = utils.get_coordinate_to_grid_row_col(
geom.GetX(total_points - 1),
geom.GetY(total_points - 1), dem)
# get the dem cells corresponding to row, col needed to generate the interpolation function
dem_array = dem_band.ReadAsArray(xoff=col,
yoff=row,
win_xsize=2,
win_ysize=2)
# define the interpolation function
bilinterp = interpolate.interp2d(ax[col:col + 2],
ay[row:row + 2],
dem_array,
kind='linear')
# find the elevation of the 1st point using the interpolation function
elevation_2 = bilinterp(geom.GetX(total_points - 1),
geom.GetY(total_points - 1))[0]
rd_range = abs(elevation_2 - elevation_1)
else:
rd_range = 0 # sometimes shape/feature have no points - in that case we say range is zero
else:
rd_length = 0
rd_range = 0
# write length value to shapefile
feature.SetField(fld_index_length, rd_length)
# write range value to shapefile
feature.SetField(fld_index_range, rd_range)
# rewrite the feature to the layer - this will in fact save the data
layer.SetFeature(feature)
geom = None
except Exception as ex:
dataSource.Destroy()
raise
# close datasource
dataSource.Destroy()
# DEBUG:
print("Finished computing length/elevation interpolation...")
def create_drainpoint_weighted_grid(input_dem, graip_db, dpsi_gridfile,
dp_shapefile, is_stream_connected):
"""
Creates a new grid file with drain point sediment production data
:param input_dem: Path to dem file
:param graip_db: Path to graip database file
:param dpsi_gridfile: Path the output grid file to which sediment data will be writen
:param dp_shapefile: Path to drainpoint shapefile
:param is_stream_connected: Flag(True/False) to indicate if sediment data grid file be created for all
drainpoints or only stream connected points
:return: None
"""
# DEBUG:
print("Starting to write sediment data to output grid file.")
dataSource = None
conn = None
try:
conn = pyodbc.connect(utils.MS_ACCESS_CONNECTION % graip_db)
cursor = conn.cursor()
# TODO: May be use the no data value from the input dem
# (ref: http://www.gdal.org/classGDALRasterBand.html#adcca51d230b5ac848c43f1896293fb50)
# create a new weighted tif file based on the dem file
dem = gdal.Open(input_dem)
geotransform = dem.GetGeoTransform()
originX = geotransform[0]
originY = geotransform[3]
pixelWidth = geotransform[1]
pixelHeight = geotransform[5]
rows = dem.RasterYSize
cols = dem.RasterXSize
# DEBUG:
print("Creating sediment output grid file.")
driver = gdal.GetDriverByName(utils.GDALFileDriver.TifFile())
number_of_bands = 1
outRaster = driver.Create(dpsi_gridfile, cols, rows, number_of_bands,
gdal.GDT_Float32)
outRaster.SetGeoTransform(
(originX, pixelWidth, 0, originY, 0, pixelHeight))
# DEBUG:
print("Initializing sediment output grid file with zeros.")
# TODO: use the band Fill() method to initialize the raster (ref:http://www.gdal.org/classGDALRasterBand.html#a55bf20527df638dc48bf25e2ff26f353)
# initialize the newly created tif file with zeros
# grid_initial_data = np.zeros((rows, cols), dtype=np.float32)
# grid_initial_data[:] = 0.0 # this causes memory error in case of big dem
outband = outRaster.GetRasterBand(1)
outband.SetNoDataValue(utils.NO_DATA_VALUE)
# initialize the newly created tif file with zeros - this solves the memory error
outband.Fill(0.0)
#outband.WriteArray(grid_initial_data)
# DEBUG:
print("Finished initializing sediment grid file.")
# set the projection of the tif file same as that of the dem
outRasterSRS = osr.SpatialReference()
outRasterSRS.ImportFromWkt(dem.GetProjectionRef())
outRaster.SetProjection(outRasterSRS.ExportToWkt())
# open the drainpoints shapefile
driver = ogr.GetDriverByName(utils.GDALFileDriver.ShapeFile())
dataSource = driver.Open(dp_shapefile, 1)
layer = dataSource.GetLayer()
# for each drain point in shape file
# DEBUG:
print("Looping over drain points in shapefile")
for dp in layer:
geom = dp.GetGeometryRef()
# find grid row and col corresponding to drain point
row, col = utils.get_coordinate_to_grid_row_col(
geom.GetX(0), geom.GetY(0), dem)
geom = None
# get the id of the drain point from shape file
graipdid = dp.GetField('GRAIPDID')
def _write_sed_accum_to_grid():
# create a 2D array to store sediment production data
sed_array = np.zeros((1, 1), dtype=np.float32)
# get current grid cell data
current_cell_data = outband.ReadAsArray(xoff=col,
yoff=row,
win_xsize=1,
win_ysize=1)
if current_cell_data[0][0] != utils.NO_DATA_VALUE:
sed_array[0][0] = current_cell_data[0][0] + dp_row.SedProd
else:
sed_array[0][0] = dp_row.SedProd
# here we are writing to a specific cell of the grid
outband.WriteArray(sed_array, xoff=col, yoff=row)
# find the drain point matching row from the DrainPoints db table
dp_row = cursor.execute(
"SELECT SedProd, StreamConnectID FROM DrainPoints WHERE GRAIPDID=?",
graipdid).fetchone()
if is_stream_connected:
if dp_row.StreamConnectID == 2:
_write_sed_accum_to_grid()
else:
_write_sed_accum_to_grid()
outband.FlushCache()
# calculate raster statistics (min, max, mean, stdDev)
outband.GetStatistics(0, 1)
# DEBUG:
print("Finished writing data to sediment grid file.")
except:
raise
finally:
if dataSource is not None:
dataSource.Destroy()
if conn:
conn.close()
dem = None
outRaster = None
def compute_length_elevation_interpolation(rd_shapefile, input_dem):
"""
Calculates road segment length and elevation and writes to roadlines shapefile
:param rd_shapefile: Path to roadlines shapefile
:param input_dem: Path to dem file
:return: None
"""
# DEBUG:
print ("Computing length/elevation interpolation...")
driver = ogr.GetDriverByName(utils.GDALFileDriver.ShapeFile())
dataSource = driver.Open(rd_shapefile, 1)
layer = dataSource.GetLayer()
layerDefn = layer.GetLayerDefn()
dem = gdal.Open(input_dem)
dem_nx = dem.RasterXSize
dem_ny = dem.RasterYSize
gt = dem.GetGeoTransform()
dem_band = dem.GetRasterBand(1)
# Compute mid-point grid spacings
# ref: http://gis.stackexchange.com/questions/7611/bilinear-interpolation-of-point-data-on-a-raster-in-python
# gt[0] dem originX
# gt[3] dem originY
# gt[1] dem cell width (in pixel)
# gt[5] dem cell height (in pixel)
ax = array([gt[0] + ix*gt[1] + gt[1]/2.0 for ix in range(dem_nx)])
ay = array([gt[3] + iy*gt[5] + gt[5]/2.0 for iy in range(dem_ny)])
try:
# delete field "Length" if it exists
fld_index = layerDefn.GetFieldIndex('Length')
if fld_index > 0:
layer.DeleteField(fld_index)
# delete "Range" if it exists
fld_index = layerDefn.GetFieldIndex('Range')
if fld_index > 0:
layer.DeleteField(fld_index)
except:
pass
# add a new field (column) 'Length' to the attribute table
layer.CreateField(ogr.FieldDefn('Length', ogr.OFTReal))
fld_index_length = layerDefn.GetFieldIndex('Length')
# add a new field (column) 'Range' to the attribute table
layer.CreateField(ogr.FieldDefn('Range', ogr.OFTReal))
fld_index_range = layerDefn.GetFieldIndex('Range')
for feature in layer:
try:
geom = feature.GetGeometryRef()
if geom:
total_points = geom.GetPointCount()
# write length value to shapefile
# feature.SetField(fld_index_length, geom.Length())
rd_length = geom.Length()
if total_points > 0:
# calculate range from the elevation of 2 end points of the road segment
# using interpolation
# first find the row, col of the dem corresponding to
# the fist point of the road segment
row, col = utils.get_coordinate_to_grid_row_col(geom.GetX(0), geom.GetY(0), dem)
# get the dem cells corresponding to row, col needed to generate the interpolation function
dem_array = dem_band.ReadAsArray(xoff=col, yoff=row, win_xsize=2, win_ysize=2)
# define the interpolation function
bilinterp = interpolate.interp2d(ax[col:col+2], ay[row:row+2], dem_array,
kind='linear')
# find the elevation of the 1st point using the interpolation function
elevation_1 = bilinterp(geom.GetX(0), geom.GetY(0))[0]
# find the row, col of the dem corresponding to
# the 2nd point of the road segment
row, col = utils.get_coordinate_to_grid_row_col(geom.GetX(total_points-1),
geom.GetY(total_points-1), dem)
# get the dem cells corresponding to row, col needed to generate the interpolation function
dem_array = dem_band.ReadAsArray(xoff=col, yoff=row, win_xsize=2, win_ysize=2)
# define the interpolation function
bilinterp = interpolate.interp2d(ax[col:col+2], ay[row:row+2], dem_array,
kind='linear')
# find the elevation of the 1st point using the interpolation function
elevation_2 = bilinterp(geom.GetX(total_points-1), geom.GetY(total_points-1))[0]
rd_range = abs(elevation_2 - elevation_1)
else:
rd_range = 0 # sometimes shape/feature have no points - in that case we say range is zero
else:
rd_length = 0
rd_range = 0
# write length value to shapefile
feature.SetField(fld_index_length, rd_length)
# write range value to shapefile
feature.SetField(fld_index_range, rd_range)
# rewrite the feature to the layer - this will in fact save the data
layer.SetFeature(feature)
geom = None
except Exception as ex:
dataSource.Destroy()
raise
# close datasource
dataSource.Destroy()
# DEBUG:
print ("Finished computing length/elevation interpolation...")
def create_drainpoint_weighted_grid(input_dem, graip_db, dpsi_gridfile, dp_shapefile, is_stream_connected):
"""
Creates a new grid file with drain point sediment production data
:param input_dem: Path to dem file
:param graip_db: Path to graip database file
:param dpsi_gridfile: Path the output grid file to which sediment data will be writen
:param dp_shapefile: Path to drainpoint shapefile
:param is_stream_connected: Flag(True/False) to indicate if sediment data grid file be created for all
drainpoints or only stream connected points
:return: None
"""
# DEBUG:
print ("Starting to write sediment data to output grid file.")
dataSource = None
conn = None
try:
conn = pyodbc.connect(utils.MS_ACCESS_CONNECTION % graip_db)
cursor = conn.cursor()
# TODO: May be use the no data value from the input dem
# (ref: http://www.gdal.org/classGDALRasterBand.html#adcca51d230b5ac848c43f1896293fb50)
# create a new weighted tif file based on the dem file
dem = gdal.Open(input_dem)
geotransform = dem.GetGeoTransform()
originX = geotransform[0]
originY = geotransform[3]
pixelWidth = geotransform[1]
pixelHeight = geotransform[5]
rows = dem.RasterYSize
cols = dem.RasterXSize
# DEBUG:
print ("Creating sediment output grid file.")
driver = gdal.GetDriverByName(utils.GDALFileDriver.TifFile())
number_of_bands = 1
outRaster = driver.Create(dpsi_gridfile, cols, rows, number_of_bands, gdal.GDT_Float32)
outRaster.SetGeoTransform((originX, pixelWidth, 0, originY, 0, pixelHeight))
# DEBUG:
print ("Initializing sediment output grid file with zeros.")
# TODO: use the band Fill() method to initialize the raster (ref:http://www.gdal.org/classGDALRasterBand.html#a55bf20527df638dc48bf25e2ff26f353)
# initialize the newly created tif file with zeros
# grid_initial_data = np.zeros((rows, cols), dtype=np.float32)
# grid_initial_data[:] = 0.0 # this causes memory error in case of big dem
outband = outRaster.GetRasterBand(1)
outband.SetNoDataValue(utils.NO_DATA_VALUE)
# initialize the newly created tif file with zeros - this solves the memory error
outband.Fill(0.0)
#outband.WriteArray(grid_initial_data)
# DEBUG:
print ("Finished initializing sediment grid file.")
# set the projection of the tif file same as that of the dem
outRasterSRS = osr.SpatialReference()
outRasterSRS.ImportFromWkt(dem.GetProjectionRef())
outRaster.SetProjection(outRasterSRS.ExportToWkt())
# open the drainpoints shapefile
driver = ogr.GetDriverByName(utils.GDALFileDriver.ShapeFile())
dataSource = driver.Open(dp_shapefile, 1)
layer = dataSource.GetLayer()
# for each drain point in shape file
# DEBUG:
print ("Looping over drain points in shapefile")
for dp in layer:
geom = dp.GetGeometryRef()
# find grid row and col corresponding to drain point
row, col = utils.get_coordinate_to_grid_row_col(geom.GetX(0), geom.GetY(0), dem)
geom = None
# get the id of the drain point from shape file
graipdid = dp.GetField('GRAIPDID')
def _write_sed_accum_to_grid():
# create a 2D array to store sediment production data
sed_array = np.zeros((1, 1), dtype=np.float32)
# get current grid cell data
current_cell_data = outband.ReadAsArray(xoff=col, yoff=row, win_xsize=1, win_ysize=1)
if current_cell_data[0][0] != utils.NO_DATA_VALUE:
sed_array[0][0] = current_cell_data[0][0] + dp_row.SedProd
else:
sed_array[0][0] = dp_row.SedProd
# here we are writing to a specific cell of the grid
outband.WriteArray(sed_array, xoff=col, yoff=row)
# find the drain point matching row from the DrainPoints db table
dp_row = cursor.execute("SELECT SedProd, StreamConnectID FROM DrainPoints WHERE GRAIPDID=?",
graipdid).fetchone()
if is_stream_connected:
if dp_row.StreamConnectID == 2:
_write_sed_accum_to_grid()
else:
_write_sed_accum_to_grid()
outband.FlushCache()
# calculate raster statistics (min, max, mean, stdDev)
outband.GetStatistics(0, 1)
# DEBUG:
print ("Finished writing data to sediment grid file.")
except:
raise
finally:
if dataSource is not None:
dataSource.Destroy()
if conn:
conn.close()
dem = None
outRaster = None
def _sindex_drain_points(mdb, dp, si):
# for each drain point in the drain points shape file find the cell value in the combined stability index grid file
# and use that value to populate the corresponding row in the drainpoints table
driver = ogr.GetDriverByName(utils.GDALFileDriver.ShapeFile())
dataSource = driver.Open(dp, GA_Update)
layer = dataSource.GetLayer()
layerDefn = layer.GetLayerDefn()
fld_index_graipdid = layerDefn.GetFieldIndex('GRAIPDID')
si_grid = gdal.Open(si)
si_band = si_grid.GetRasterBand(1)
field_to_create = 'SI'
try:
#delete field if it exists in drainpoints shapefile
fld_index_dp = layerDefn.GetFieldIndex(field_to_create)
if fld_index_dp > 0:
layer.DeleteField(fld_index_dp)
# add a new field (column) to the attribute table of drainpoints shapefile
layer.CreateField(ogr.FieldDefn(field_to_create, ogr.OFTReal))
fld_index_dp = layerDefn.GetFieldIndex(field_to_create)
except:
pass
try:
conn = pyodbc.connect(utils.MS_ACCESS_CONNECTION % mdb)
cursor = conn.cursor()
for feature in layer:
geom = feature.GetGeometryRef()
total_points = geom.GetPointCount()
if total_points > 0:
# calculate range from the elevation of 2 end points of the road segment
row, col = utils.get_coordinate_to_grid_row_col(
geom.GetX(0), geom.GetY(0), si_grid)
si_cell_data = si_band.ReadAsArray(xoff=col,
yoff=row,
win_xsize=1,
win_ysize=1)
graipdid = feature.GetFieldAsInteger(fld_index_graipdid)
dp_row = cursor.execute(
"SELECT * FROM DrainPoints WHERE GRAIPDID=%d" %
graipdid).fetchone()
if dp_row:
if si_cell_data[0][0] == si_band.GetNoDataValue():
dp_row.SI = -9999
else:
dp_row.SI = float(si_cell_data[0][0])
update_sql = "UPDATE DrainPoints SET SI=? WHERE GRAIPDID=?"
data = (dp_row.SI, dp_row.GRAIPDID)
cursor.execute(update_sql, data)
# write si data to drainpoints shapefile
feature.SetField(fld_index_dp, data[0])
# rewrite the feature to the layer - this will in fact save the data to the file
layer.SetFeature(feature)
geom = None
conn.commit()
except:
raise
finally:
# cleanup
if conn:
conn.close()
if dataSource:
dataSource.Destroy()
