gsflow.builder.flow_accumulation Module

class gsflow.builder.flow_accumulation.FlowAccumulation(data, xcenters, ycenters, acc_type='d8', hru_type=None, closed_basin=False, flow_dir_array=None, verbose=False)

Class to perform flow accumulation on a DEM (raster) or resampled to a model grid

Parameters

datanp.ndarray

two dimensional numpy array of dem data

xcentersnp.ndarray

a two dimensional array of x coordinate cell centers

ycentersnp.ndarray

two dimensional array of y coordinate cell centers

acc_typestr

flow accumulation type, currently supported options are “d8”

hru_typenp.array

optional numpy array of hru type numbers that can be used as a masking array to exclude lakes, swales, etc… 0 == inactive 1 == land (included in flow accumulation) 2 == lake (excluded from flow accumulation) 3 == swale (excluded from flow accumulation)

closed_basinbool

method to indicate that basin is closed without considering lake flow. If true hru_type 2 is used in the flow direction calculations. False ignores hru_type 2.

flow_dir_arraynp.ndarray

previously calculated flow direction array of dimension nrow, ncol that can be supplied to FlowAccumulation

verbosebool

flag to print verbose output

Attributes

get_vectors

Method to get flow vectors array

Methods

define_subbasins(self, pour_points, modelgrid)	Method to perform sub-basin delineation on the flow direction array
define_watershed(self, pour_point, modelgrid)	Method to perform watershed delineation on the flow direction array
flow_accumulation(self)	NIDP method to calculate the flow accumulation array using
flow_directions(self[, dijkstra, breach])	Method to get flow directions array
get_cascades(self, streams[, pour_point, …])	Method to calculate cascade parameters for PRMS
get_dem_data(self)	Method to get processed DEM data after flow accumulation
load_cascades(f)	Method to load a saved binary cascades file
load_streams(f)	Method to load a saved binary streams file
make_streams(self, fdir_array, fa_array, …)	Method to make streams for both PRMS and MODFLOW SFR

get_hru_type

define_subbasins(self, pour_points, modelgrid, fmt='rowcol')

Method to perform sub-basin delineation on the flow direction array

Parameters

pour_pointsstr, tuple

pour point can be supplied as either a shapefile, a list with an [(x, y)] tuple of coordinates, or as the model zero based [(row, column)] location.

modelgridflopy.discretization.StructuredGrid

structured grid instance from flopy

fmtstr

format of the pour point information. Acceptable types include “xy”, “rowcol”, and “shp”

Returns

np.ndarraydelinated array of the watershed (1 is active,

0 is inactive)

define_watershed(self, pour_point, modelgrid, fmt='rowcol')

Method to perform watershed delineation on the flow direction array

Parameters

pour_pointstr, tuple

pour point can be supplied as either a shapefile, a list with an [(x, y)] tuple of coordinates, or as the model zero based [(row, column)] location.

modelgridflopy.discretization.StructuredGrid

structured grid instance from flopy

fmtstr

format of the pour point information. Acceptable types include “xy”, “rowcol”, and “shp”

Returns

np.ndarraydelinated array of the watershed (1 is active,

0 is inactive)

flow_accumulation(self)

NIDP method to calculate the flow accumulation array using

Returns

np.ndarray of flow directions

flow_directions(self, dijkstra=False, breach=0.0)

Method to get flow directions array

Parameters

dijkstrabool

method to use a modified dijkstra algorithmn to solve tricky flat areas. Default is False and uses a distance based topology method to solve flat areas.

breachfloat

absolute value of breaching tolerance for digital dams. Use caution while applying breaching values. These should be small numbers.

Returns

np.ndarray of flow directions

get_cascades(self, streams, pour_point=None, modelgrid=None, fmt='rowcol')

Method to calculate cascade parameters for PRMS

Parameters

streams_StreamsObj

Stream information object returned from the FlowAccumulation.make_streams method

pour_pointlist, str

optional, but required if watershed deliniation has not been run prior to running get_cascades. pour point can be supplied as either a shapefile, a list with an [(x, y)] tuple of coordinates, or as the model zero based [(row, column)] location.

modelgridflopy.discretization.StructuredGrid

fmtstr

format of the pour point information. Acceptable types include “xy”, “rowcol”, and “shp”

Returns

_Cascades object

get_dem_data(self)

Method to get processed DEM data after flow accumulation

Returns

np.ndarray

property get_vectors

Method to get flow vectors array

Returns

(u, v): tuple (np.ndarray of flow vectors)

static load_cascades(f)

Method to load a saved binary cascades file

Parameters

fstr

file name

Returns

_Cascades

static load_streams(f)

Method to load a saved binary streams file

Parameters

fstr

file name

Returns

_StreamsObj

make_streams(self, fdir_array, fa_array, threshold, min_stream_len=None, max_reach=None, default_slope=0.001, min_slope=0.0001, max_slope=1.0)

Method to make streams for both PRMS and MODFLOW SFR

Parameters

fdir_arraynp.ndarray

flow direction array

fa_arraynp.ndarray

flow accumulation array

thresholdfloat

accumulated area threshold for defining streams

min_stream_lenint

optional minimum stream length in number of cells

max_reachint

optional maximum number of reach cells per segment

default_slopefloat

default slope value for setting SFR slope of all cells

min_slopefloat

minimum slope calculated by make streams for SFR

max_slopefloat

maximum SFR slope calculated by make streams

Returns

_StreamsObjobject containing SFR and PRMS stream information